nih-gov/pubmed.ncbi.nlm.nih.gov/1878827/index.html

3639 lines
No EOL
125 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en" >
<head itemscope itemtype="http://schema.org/WebPage" prefix="og: http://ogp.me/ns#" >
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<!-- Mobile properties -->
<meta name="HandheldFriendly" content="True">
<meta name="MobileOptimized" content="320">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="preconnect" href="https://cdn.ncbi.nlm.nih.gov">
<link rel="preconnect" href="https://www.ncbi.nlm.nih.gov">
<link rel="preconnect" href="https://www.google-analytics.com">
<link rel="stylesheet" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/css/output.ba8099dd2df4.css" type="text/css">
<link rel="stylesheet" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/css/output.452c70ce66f7.css" type="text/css">
<link rel="stylesheet" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/css/output.7bf600913d6e.css" type="text/css">
<link rel="stylesheet" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/css/output.0bfa59184c7a.css" type="text/css">
<title>Comparison of search strategies on CD Plus/MEDLINE - PubMed</title>
<link rel="preload" as="font" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/uswds/dist/fonts/merriweather-bold-webfont.woff2" type="font/woff2" crossorigin />
<!-- Favicons -->
<link rel="shortcut icon" type="image/ico" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon.ico" />
<link rel="icon" type="image/png" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon.png" />
<!-- 192x192, as recommended for Android
http://updates.html5rocks.com/2014/11/Support-for-theme-color-in-Chrome-39-for-Android
-->
<link rel="icon" type="image/png" sizes="192x192" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon-192.png" />
<!-- 57x57 (precomposed) for iPhone 3GS, pre-2011 iPod Touch and older Android devices -->
<link rel="apple-touch-icon-precomposed" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon-57.png">
<!-- 72x72 (precomposed) for 1st generation iPad, iPad 2 and iPad mini -->
<link rel="apple-touch-icon-precomposed" sizes="72x72" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon-72.png">
<!-- 114x114 (precomposed) for iPhone 4, 4S, 5 and post-2011 iPod Touch -->
<link rel="apple-touch-icon-precomposed" sizes="114x114" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon-114.png">
<!-- 144x144 (precomposed) for iPad 3rd and 4th generation -->
<link rel="apple-touch-icon-precomposed" sizes="144x144" href="https://cdn.ncbi.nlm.nih.gov/coreutils/nwds/img/favicons/favicon-144.png">
<!-- For Pinger + Google Optimize integration (NS-820) -->
<meta name="ncbi_sg_optimize_id" content="">
<!-- Mobile browser address bar color -->
<meta name="theme-color" content="#20558a">
<!-- Preserve the Referrer when going from HTTPS to HTTP -->
<meta name="referrer" content="origin-when-cross-origin">
<meta name="ncbi_pinger_gtm_track" content="true"/>
<!-- Logging params: Pinger defaults -->
<meta name="ncbi_app" content="pubmed" />
<meta name="ncbi_db" content="pubmed" />
<meta name="ncbi_phid" content="BA3600017CB8DF0500002981286C5FCE.1.m_7" />
<meta name="ncbi_pinger_stat_url" content="https://www.ncbi.nlm.nih.gov/stat" />
<meta name="log_category" content="literature" />
<meta name="ncbi_cost_center" content="pubmed" />
<!-- Logging params: Pinger custom -->
<meta name="ncbi_pdid" content="abstract" />
<meta name="log_op" content="retrieve" />
<meta name="uid" content="1878827" />
<meta name="ncbi_uid" content="1878827" />
<meta name="log_displayeduids" content="1878827" />
<meta name="log_source_db" content="pubmed,pmc" />
<meta name="log_icons_present" content="true" />
<meta name="ncbi_search_id" content="baKULWJvIKEmjmzpBLKMtQ:647ff15141af266103a93759ef71cd80" />
<meta name="ncbi_adj_nav_search_id" content="O76G0u_mXSrhAito6o4KYg:647ff15141af266103a93759ef71cd80" />
<!-- Social meta tags for unfurling urls -->
<meta name="description" content="Strategy A would be more valuable to researchers doing extensive reviews, whereas strategy B would be useful for the busy clinician who simply wants a few appropriate references quickly and is willing to sacrifice comprehensive retrieval in the interest of efficiency."><meta name="keywords" content="pmid:1878827, PMC1335828, Research Support, Non-U.S. Gov&#x27;t, L C Wright, H J Sutherland, J E Till, Algorithms*, CD-ROM*, Evaluation Studies as Topic, Information Storage and Retrieval*, MEDLINE, Surveys and Questionnaires, PubMed Abstract, NIH, NLM, NCBI, National Institutes of Health, National Center for Biotechnology Information, National Library of Medicine, MEDLINE"><meta name="robots" content="index,nofollow,noarchive"><meta property="og:title" content="Comparison of search strategies on CD Plus/MEDLINE - PubMed"><meta property="og:url" content="https://pubmed.ncbi.nlm.nih.gov/1878827/"><meta property="og:description" content="Strategy A would be more valuable to researchers doing extensive reviews, whereas strategy B would be useful for the busy clinician who simply wants a few appropriate references quickly and is willing to sacrifice comprehensive retrieval in the interest of efficiency."><meta property="og:image" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg"><meta property="og:image:secure_url" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg"><meta property="og:type" content="website"><meta property="og:site_name" content="PubMed"><meta name="twitter:domain" content="pubmed.ncbi.nlm.nih.gov"><meta name="twitter:card" content="summary_large_image"><meta name="twitter:title" content="Comparison of search strategies on CD Plus/MEDLINE - PubMed"><meta name="twitter:url" content="https://pubmed.ncbi.nlm.nih.gov/1878827/"><meta name="twitter:description" content="Strategy A would be more valuable to researchers doing extensive reviews, whereas strategy B would be useful for the busy clinician who simply wants a few appropriate references quickly and is willing to sacrifice comprehensive retrieval in the interest of efficiency."><meta name="twitter:image" content="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/pubmed-meta-image-v2.jpg">
<!-- OpenSearch XML -->
<link rel="search" type="application/opensearchdescription+xml" href="https://cdn.ncbi.nlm.nih.gov/pubmed/persistent/opensearch.xml" title="PubMed search">
<!-- Disables severely broken elements when no JS -->
<noscript>
<link rel="stylesheet" type="text/css" href="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/core/no-script.css">
</noscript>
<meta name="citation_title" content="Comparison of search strategies on CD Plus/MEDLINE">
<meta name="citation_authors" content="Wright LC;Sutherland HJ;Jackson JI;Till JE;">
<meta name="citation_date" content="09/01/1991">
<meta name="citation_publisher" content="CMAJ">
<meta name="citation_journal_title" content="CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne">
<meta name="citation_pmid" content="1878827">
<meta name="citation_abstract_html_url" content="https://pubmed.ncbi.nlm.nih.gov/1878827/">
<meta name="citation_volume" content="145">
<meta name="citation_issue" content="5">
<meta name="citation_doi" content="">
<meta name="citation_issn" content="0820-3946">
<link rel="canonical" href="https://pubmed.ncbi.nlm.nih.gov/1878827/" />
</head>
<body >
<noscript>
<div class="no-script-banner" id="no-script-banner">
<div class="warning-message">
<div class="warning-message-text">
This site needs JavaScript to work properly. Please enable it to take advantage of the complete set of features!
</div>
</div>
</div>
</noscript>
<div class="no-session-banner" id="no-session-banner" hidden>
<div class="warning-message">
<div class="warning-message-text">
Clipboard, Search History, and several other advanced features are temporarily unavailable.
</div>
<button class="close-banner-button"
title="Close Clipboard and Search History not available warning banner"
ref="linksrc=close_no_session_banner"
aria-controls="no-session-banner"
aria-label="Close Clipboard and Search History not available warning banner"
aria-expanded="true">
</button>
</div>
</div>
<a class="usa-skipnav" href="#article-details">
Skip to main page content
</a>
<!-- ========== BEGIN HEADER ========== -->
<section class="usa-banner">
<div class="usa-accordion">
<header class="usa-banner-header">
<div class="usa-grid usa-banner-inner">
<img src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/favicons/favicon-57.png" alt="U.S. flag" />
<p>An official website of the United States government</p>
<button
class="usa-accordion-button usa-banner-button"
aria-expanded="false"
aria-controls="gov-banner-top"
>
<span class="usa-banner-button-text">Here's how you know</span>
</button>
</div>
</header>
<div
class="usa-banner-content usa-grid usa-accordion-content"
id="gov-banner-top"
>
<div class="usa-banner-guidance-gov usa-width-one-half">
<img
class="usa-banner-icon usa-media_block-img"
src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-dot-gov.svg"
alt="Dot gov"
/>
<div class="usa-media_block-body">
<p>
<strong>The .gov means its official.</strong>
<br />
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure youre on a federal
government site.
</p>
</div>
</div>
<div class="usa-banner-guidance-ssl usa-width-one-half">
<img
class="usa-banner-icon usa-media_block-img"
src="https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-https.svg"
alt="Https"
/>
<div class="usa-media_block-body">
<p>
<strong>The site is secure.</strong>
<br />
The <strong>https://</strong> ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
</p>
</div>
</div>
</div>
</div>
</section>
<div class="usa-overlay"></div>
<header class="ncbi-header" role="banner" data-section="Header">
<div class="usa-grid">
<div class="usa-width-one-whole">
<div class="ncbi-header__logo">
<a href="https://www.ncbi.nlm.nih.gov/" class="logo" aria-label="NCBI Logo" data-ga-action="click_image" data-ga-label="NIH NLM Logo">
<img src="https://www.ncbi.nlm.nih.gov/coreutils/nwds/img/logos/AgencyLogo.svg" alt="NIH NLM Logo" />
</a>
</div>
<div class="ncbi-header__account">
<a id="account_login" href="https://account.ncbi.nlm.nih.gov" class="usa-button header-button" style="display:none" data-ga-action="open_menu" data-ga-label="account_menu">Log in</a>
<button id="account_info" class="header-button" style="display:none"
aria-controls="account_popup">
<span class="fa fa-user" aria-hidden="true"></span>
<span class="username desktop-only" aria-hidden="true" id="uname_short"></span>
<span class="sr-only">Show account info</span>
</button>
</div>
<div class="ncbi-popup-anchor">
<div class="ncbi-popup account-popup" id="account_popup" aria-hidden="true">
<div class="ncbi-popup-head">
<button class="ncbi-close-button" data-ga-action="close_menu" data-ga-label="account_menu"><span class="fa fa-times"></span><span class="usa-sr-only">Close</span></button>
<h4>Account</h4>
</div>
<div class="account-user-info">
Logged in as:<br/>
<b><span class="username" id="uname_long">username</span></b>
</div>
<div class="account-links">
<ul class="usa-unstyled-list">
<li><a id="account_myncbi" href="/myncbi/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_myncbi">Dashboard</a></li>
<li><a id="account_pubs" href="/myncbi/collections/bibliography/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_pubs">Publications</a></li>
<li><a id="account_settings" href="/account/settings/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_settings">Account settings</a></li>
<li><a id="account_logout" href="/account/signout/" class="set-base-url" data-ga-action="click_menu_item" data-ga-label="account_logout">Log out</a></li>
</ul>
</div>
</div>
</div>
</div>
</div>
</header>
<div role="navigation" aria-label="access keys">
<a id="nws_header_accesskey_0" href="https://www.ncbi.nlm.nih.gov/guide/browsers/#ncbi_accesskeys" class="usa-sr-only" accesskey="0" tabindex="-1">Access keys</a>
<a id="nws_header_accesskey_1" href="https://www.ncbi.nlm.nih.gov" class="usa-sr-only" accesskey="1" tabindex="-1">NCBI Homepage</a>
<a id="nws_header_accesskey_2" href="/myncbi/" class="set-base-url usa-sr-only" accesskey="2" tabindex="-1">MyNCBI Homepage</a>
<a id="nws_header_accesskey_3" href="#maincontent" class="usa-sr-only" accesskey="3" tabindex="-1">Main Content</a>
<a id="nws_header_accesskey_4" href="#" class="usa-sr-only" accesskey="4" tabindex="-1">Main Navigation</a>
</div>
<section data-section="Alerts">
<div class="ncbi-alerts-placeholder"></div>
</section>
<!-- ========== END HEADER ========== -->
<a id="maincontent" aria-label="Main page content below" role="navigation"></a>
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<form action="/" method="get" autocomplete="off" class="usa-search usa-search-big search-form content-page-layout" id="search-form" role="search">
<div class="inner-wrap">
<a class="pubmed-logo"
aria-label="Pubmed Logo"
href="/"
data-ga-category="featured_link"
data-ga-action="pubmed_logo">
<img src="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/core/images/pubmed-logo-blue.svg" alt="pubmed logo" />
</a>
<a href="#" class="search-input-trigger" data-alt-title="Hide search bar" title="Show search bar" aria-label="Show search bar">
</a>
<div role="search" class="search-input">
<div class="form-field ">
<label class="usa-sr-only" for="id_term">
Search:
</label>
<input
type="search"
name="term"
data-skip-ie-scroll-to-top=""
data-replace-term-with-exact=""
data-exact-query=""
placeholder=""
class="term-input"
required="required"
id="id_term"/><a href="#" class="clear-btn" aria-label="Clear search input" title="Clear search input" role="button" data-pinger-ignore></a><button type="submit" class="search-btn" aria-label="Search" disabled data-pinger-ignore><span class="usa-search-submit-text">Search</span></button>
</div>
</div>
<!-- Create alert and Create RSS are buttons that look like links -->
<!-- Better for them to look like buttons but no space -->
<div class="search-links-wrapper content-page-layout">
<div class="search-links">
<a href="/advanced/"
class="search-input-link adv-search-link"
data-ga-category="featured_link"
data-ga-action="adv_search">Advanced</a>
<a href="/clipboard/"
class="search-input-link clipboard-link hidden"
data-ga-category="featured_link"
data-ga-action="clipboard">
Clipboard <span class="amount-in-clipboard"></span>
</a>
</div>
<span class="search-input-link user-guide-link" role="navigation" aria-label="User guide">
<a href="/help/"
data-ga-category="featured_link"
data-ga-action="user_guide">
User Guide
</a>
</span>
</div>
</div>
</form>
<div id="article-page-header">
<div id="article-top-actions-bar" class="article-top-actions-bar">
<div class="inner-wrap">
<div class="actions-container">
<div class="return-to-search">
</div>
<div class="multiple-results-actions " role="region" aria-label="save, email, send to">
<button id="save-results-panel-trigger"
type="button"
class="save-results save-results-panel-trigger"
aria-expanded="false"
aria-controls="save-action-panel"
data-ga-category="save_share"
data-ga-action="save"
data-ga-label="open">
Save
</button><button id="email-results-panel-trigger"
type="button"
class="email-results email-results-panel-trigger"
aria-expanded="false"
aria-controls="email-action-panel"
data-ga-category="save_share"
data-ga-action="email"
data-ga-label="open">
Email
</button><div class="more-actions dropdown-block"><button id="more-actions-trigger"
type="button"
class="trigger more-actions-trigger"
ref="linksrc=show_moreactions_btn"
aria-label="Send to"
aria-controls="more-actions-dropdown">Send to</button><div id="more-actions-dropdown" class="dropdown dropdown-container" hidden><div class="content"><ul class="more-actions-links"><li><a class="clipboard-panel-trigger dropdown-block-link "
href="#"
role="button"
data-ga-category="save_share"
data-ga-action="clipboard"
data-ga-label="send">
Clipboard
</a></li><li><a role="button" class="dropdown-block-link bibliography-trigger-target" href="https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F%23open-bibliography-panel">My Bibliography</a></li><li><a role="button" class="dropdown-block-link collections-trigger-target" href="https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F%23open-collections-panel">Collections</a></li><li><a role="button" class="citation-manager-panel-trigger dropdown-block-link citation-manager-trigger-target" href="#">Citation manager</a></li></ul></div></div></div>
</div>
<div class="display-options" data-format-key="format"
data-default-format-value="abstract"
data-current-format-value="abstract" role="region">
<button
class="trigger usa-button"
title="Change format"
data-ga-category="display_options"
data-ga-action="display_options_dialog">
<span class="button-label">Display options</span>
</button>
<div class="dropdown" hidden>
<div class="title">
Display options
</div>
<div class="content">
<div class="format-container">
<span class="option-label">
Format
</span>
<select name="format" data-initial-value="abstract" aria-label="Display format" id="article-display-format">
<option value="abstract">Abstract</option>
<option value="pubmed">PubMed</option>
<option value="pmid">PMID</option>
</select>
</div>
</div>
</div>
</div>
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
</div>
</div>
</div>
<div id="article-panels-container" class="article-panels-container">
<div id="save-action-panel" class="save-action-panel action-panel" aria-hidden="true">
<div class="inner-wrap">
<h2 class="action-panel-heading">
Save citation to file
</h2>
<form id="save-action-panel-form"
class="action-panel-content action-form"
action="/results-export-ids/"
data-by-search-action="/results-export-search-data/"
data-by-ids-action="/results-export-ids/"
method="post"
data-by-search-method="post"
data-by-ids-method="post">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="action-panel-control-wrap">
<label for="save-action-format" class="action-panel-label">
Format:
</label>
<select id="save-action-format" name="results-format" class="action-panel-selector">
<option value="summary-text">Summary (text)</option>
<option value="pubmed-text">PubMed</option>
<option value="pmid">PMID</option>
<option value="abstract">Abstract (text)</option>
<option value="csv">CSV</option>
</select>
</div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Saving..."
data-ga-category="save_share"
data-ga-action="save"
data-ga-label="save">
Create file
</button>
<button class="action-panel-cancel"
aria-label="Close 'Save citations to file' panel"
ref="linksrc=close_save_panel"
aria-controls="save-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="save"
data-ga-label="cancel">
Cancel
</button>
</div>
</form>
</div>
</div>
<div id="email-action-panel"
class="email-action-panel action-panel"
aria-hidden="true"
data-recaptcha-script-url="https://www.recaptcha.net/recaptcha/enterprise.js?render=explicit&onload=onloadCaptchaCallback"
data-recaptcha-enabled="true">
<div class="inner-wrap">
<h2 class="action-panel-heading">
Email citation
</h2>
<form id="email-action-panel-form"
class="action-panel-content action-form"
action="/send-email/"
data-by-search-action="/results-export-email-by-search-data/"
data-by-ids-action="/send-email/"
data-by-search-method="post"
data-by-ids-method="post"
method="post"
>
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="action-panel-control-wrap">
<span class="action-panel-label">
Subject:
</span>
<span class="email-subject" id="email-subject" aria-label="Email subject">1 selected item: 1878827 - PubMed</span>
<input type="hidden" name="email-subject" value="1 selected item: 1878827"/>
<input type="hidden" name="email-subject-hash" value="e591b097ef60454e31f1dd2940017640cec5a48d54fd30a4ac1168498e6f73bc"/>
</div>
<div class="action-panel-control-wrap">
<label for="email-to" class="action-panel-label required-field-asterisk">
To:
</label>
<input type="email" aria-label="Recipient Email Address" placeholder="email@example.com" id="email-to" class="email-to" pattern="^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$" maxlength="100" required>
</div>
<div class="action-panel-control-wrap">
<label for="email-from" class="action-panel-label">
From:
</label>
<input type="email" aria-label="Sender Email Address" placeholder="email@example.com" id="email-from" class="email-from" pattern="^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$" maxlength="256">
</div>
<div class="action-panel-control-wrap">
<label for="email-citation-format" class="action-panel-label">
Format:
</label>
<select id="email-citation-format" name="citation-format" class="action-panel-selector email-citation-format">
<option selected="selected" value="summary">Summary</option>
<option value="summary-text">Summary (text)</option>
<option value="abstract">Abstract</option>
<option value="abstract-text">Abstract (text)</option>
</select>
</div>
<div class="include-supplemental-container">
<input type="checkbox" aria-label="Include MeSH and other data" name="include-supplemental" id="email-include-supplemental" class="email-include-supplemental">
<label for="email-include-supplemental" class="email-include-supplemental-label">MeSH and other data</label>
</div>
<div class="form-field recaptcha ">
<div class="g-recaptcha" id="id-recaptcha" data-sitekey="6LfsWHMdAAAAAClKbtOpjQ2pMjgsGxvv7NdZW9uI"></div>
</div>
<div id="captcha-error-message" class="usa-input-error-message captcha-validation-message" role="alert"></div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Sending..."
data-ga-category="save_share"
data-ga-action="email"
data-ga-label="send">
Send email
</button>
<button class="action-panel-cancel"
aria-label="Close 'Email citations' panel"
ref="linksrc=close_email_panel"
aria-controls="email-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="email"
data-ga-label="cancel">
Cancel
</button>
</div>
<input type="hidden" name="email-search-details" value="" />
<input type="hidden" name="email-search-details-hash" value="0e42663a6c3bd85498fcb88798998fed7bfdc45d457db35281e41afe13cc0524" />
</form>
</div>
</div>
<div id="collections-action-panel"
class="collections-action-panel action-panel in-progress-dots-panel"
aria-hidden="true"
data-collections-open-panel-enabled="false"
data-collections-open-panel-url-hash="#open-collections-panel">
<div class="inner-wrap">
<h3 class="action-panel-heading">
Add to Collections
</h3>
<form id="collections-action-panel-form"
class="collections-action-panel-form action-panel-content action-form action-panel-smaller-selectors"
data-existing-collections-url="/list-existing-collections/"
data-add-to-existing-collection-url="/add-to-existing-collection/"
data-create-and-add-to-new-collection-url="/create-and-add-to-new-collection/"
data-get-article-ids-by-search-url="/get-article-ids-by-search/"
data-myncbi-max-collection-name-length="100"
data-add-to-collection-max-amount="1000"
data-collections-root-url="https://www.ncbi.nlm.nih.gov/myncbi/collections/">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="choice-group" role="radiogroup">
<ul class="radio-group-items">
<li>
<input type="radio"
id="collections-action-panel-new"
class="collections-new"
name="collections"
value="new"
data-ga-category="save_share"
data-ga-action="collections"
data-ga-label="collections_radio_new">
<label for="collections-action-panel-new">Create a new collection</label>
</li>
<li>
<input type="radio"
id="collections-action-panel-existing"
class="collections-existing"
name="collections"
value="existing"
checked="true"
data-ga-category="save_share"
data-ga-action="collections"
data-ga-label="collections_radio_existing">
<label for="collections-action-panel-existing">Add to an existing collection</label>
</li>
</ul>
</div>
<div class="controls-wrapper">
<div class="action-panel-control-wrap new-collections-controls">
<label for="collections-action-panel-add-to-new" class="action-panel-label required-field-asterisk">
Name your collection:
</label>
<input
type="text"
name="add-to-new-collection"
id="collections-action-panel-add-to-new"
class="collections-action-add-to-new"
pattern="[^&quot;&amp;=&lt;&gt;\/]*" title="The following characters are not allowed in the Name field: &quot;&amp;=&lt;&gt;/"
maxlength="100"
data-ga-category="save_share"
data-ga-action="create_collection"
data-ga-label="non_favorties_collection">
<div class="collections-new-name-too-long usa-input-error-message selection-validation-message">
Name must be less than 100 characters
</div>
</div>
<div class="action-panel-control-wrap existing-collections-controls">
<label for="collections-action-panel-add-to-existing" class="action-panel-label">
Choose a collection:
</label>
<select id="collections-action-panel-add-to-existing"
class="action-panel-selector collections-action-add-to-existing"
data-ga-category="save_share"
data-ga-action="select_collection"
data-ga-label="($('#collections-action-add-to-existing').val() === 'Favorites') ? 'Favorites' : 'non_favorites_collection'">
</select>
<div class="collections-retry-load-on-error usa-input-error-message selection-validation-message">
Unable to load your collection due to an error<br>
<a href="#">Please try again</a>
</div>
</div>
</div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Adding..."
data-pinger-ignore
data-ga-category="save_share"
data-ga-action="collections"
data-ga-label="add">
Add
</button>
<button class="action-panel-cancel"
aria-label="Close 'Add to Collections' panel"
ref="linksrc=close_collections_panel"
aria-controls="collections-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="collections"
data-ga-label="cancel">
Cancel
</button>
</div>
</form>
</div>
</div>
<div id="bibliography-action-panel"
class="bibliography-action-panel action-panel in-progress-dots-panel"
aria-hidden="true"
data-bibliography-open-panel-enabled="false"
data-bibliography-open-panel-url-hash="#open-bibliography-panel">
<div class="inner-wrap">
<h3 class="action-panel-heading">
Add to My Bibliography
</h3>
<form id="bibliography-action-panel-form"
class="bibliography-action-panel-form action-panel-content action-form action-panel-smaller-selectors"
data-add-to-bibliography-max-amount="100"
data-add-to-bibliography-batch-size="10"
data-bibliography-delegates-url="/list-bibliography-delegates/"
data-add-to-bibliography-url="/add-to-bibliography/"
data-get-article-ids-by-search-url="/get-article-ids-by-search/"
data-mybib-root-url="https://www.ncbi.nlm.nih.gov/myncbi/collections/mybibliography/">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="action-panel-control-wrap bibliographies-controls">
<div class="choice-group">
<ul class="bibliographies-action-add radio-group-items">
<li>
<input name="bibliography" id="my-bibliography" class="my-bibliography" type="radio" checked/>
<label for="my-bibliography">My Bibliography</label>
</li>
</ul>
</div>
</div>
<div class="bibliographies-retry-load-on-error usa-input-error-message selection-validation-message">
Unable to load your delegates due to an error<br>
<a href="#">Please try again</a>
</div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Adding..."
data-pinger-ignore>
Add
</button>
<button class="action-panel-cancel"
aria-label="Close 'Add to bibliography' panel"
ref="linksrc=close_bibliography_panel"
aria-controls="bibliography-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="mybib"
data-ga-label="cancel">
Cancel
</button>
</div>
</form>
</div>
</div>
<div id="saved-search-action-panel" class="saved-search-action-panel action-panel " aria-hidden="true"
data-saved-search-open-panel-enabled="false"
data-saved-search-open-panel-url-hash="#open-saved-search-panel">
<div class="inner-wrap">
<h2 class="action-panel-heading">
Your saved search
</h2>
<form id="saved-search-action-panel-form"
class="saved-search-action-panel-form action-panel-content action-form"
data-create-saved-search-url="/create-saved-search/"
data-try-search-terms-url="/try-search-term/"
data-saved-search-root-url="https://www.ncbi.nlm.nih.gov/myncbi/searches/">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="action-panel-control-wrap">
<label for="saved-search-name" class="action-panel-label saved-search-name-label required-field-asterisk">
Name of saved search:
</label>
<input maxlength="200"
type="text"
name="saved-search-name"
id="saved-search-name"
class="saved-search-name"
value=""
required
pattern="[^&quot;&amp;=&lt;&gt;\/]*" title="The following characters are not allowed in the Name field: &quot;&amp;=&lt;&gt;/">
</div>
<div class="action-panel-control-wrap">
<label for="saved-search-term" class="action-panel-label required-field-asterisk">
Search terms:
</label>
<textarea name="saved-search-term" id="saved-search-term" class="saved-search-term" required></textarea>
</div>
<div class="test-search-term-wrap">
<a href="#" class="try-search-term">Test search terms</a>
</div>
<div class="choice-group action-panel-extra-margin-top">
<span class="action-panel-label" id="fieldset-label">
Would you like email updates of new search results?
</span>
<fieldset id="saved-search-alert" aria-describedby="fieldset-label">
<legend class="usa-sr-only">Saved Search Alert Radio Buttons</legend>
<ul class="radio-group-items">
<li>
<input type="radio" id="saved-search-alert-yes" class="saved-search-alert-yes" name="saved-search-alert" value="yes" checked>
<label for="saved-search-alert-yes" class="action-panel-label">Yes</label>
</li>
<li>
<input aria-label="No radio input" type="radio" id="saved-search-alert-no" class="saved-search-alert-no" name="saved-search-alert" value="no">
<label for="saved-search-alert-no" class="action-panel-label">No</label>
</li>
</ul>
</fieldset>
</div>
<div class="alert-schedule-wrap">
<div class="action-panel-control-wrap">
<label class="action-panel-label">
Email:
</label>
<span aria-label="Email address" id="saved-search-email" class="action-panel-label"><span class="action-panel-label-bold"></span> (<a class="myncbi-account-settings" href="https://www.ncbi.nlm.nih.gov/account/settings/">change</a>)</span>
</div>
<div class="action-panel-control-wrap action-panel-extra-margin-top">
<label for="saved-search-frequency" class="action-panel-label">
Frequency:
</label>
<select id="saved-search-frequency" class="no-border-panel-selector saved-search-frequency">
<option value="monthly">Monthly</option>
<option value="weekly">Weekly</option>
<option value="daily">Daily</option>
</select>
</div>
<div class="action-panel-control-wrap saved-search-monthly-additional">
<label for="saved-search-monthly-on-day" class="action-panel-label">
Which day?
</label>
<select id="saved-search-monthly-on-day" class="no-border-panel-selector">
<option value="Sunday">The first Sunday</option>
<option value="Monday">The first Monday</option>
<option value="Tuesday">The first Tuesday</option>
<option value="Wednesday">The first Wednesday</option>
<option value="Thursday">The first Thursday</option>
<option value="Friday">The first Friday</option>
<option value="Saturday">The first Saturday</option>
<option value="day">The first day</option>
<option value="weekday">The first weekday</option>
</select>
</div>
<div class="action-panel-control-wrap saved-search-weekly-additional">
<label for="saved-search-weekly-on-day" class="action-panel-label">
Which day?
</label>
<select id="saved-search-weekly-on-day" class="no-border-panel-selector saved-search-weekly-on-day">
<option value="Sunday">Sunday</option>
<option value="Monday">Monday</option>
<option value="Tuesday">Tuesday</option>
<option value="Wednesday">Wednesday</option>
<option value="Thursday">Thursday</option>
<option value="Friday">Friday</option>
<option value="Saturday">Saturday</option>
</select>
</div>
<div class="action-panel-control-wrap">
<label for="saved-search-report" class="action-panel-label">
Report format:
</label>
<select id="saved-search-report" class="no-border-panel-selector saved-search-report">
<option value="DocSum">Summary</option>
<option value="DocSumText">Summary (text)</option>
<option value="Abstract">Abstract</option>
<option value="AbstractText">Abstract (text)</option>
<option value="MEDLINE">PubMed</option>
</select>
</div>
<div class="action-panel-control-wrap">
<label for="saved-search-amount" class="action-panel-label">
Send at most:
</label>
<select id="saved-search-amount" class="no-border-panel-selector saved-search-amount">
<option value="1">1 item</option>
<option value="5" selected>5 items</option>
<option value="10">10 items</option>
<option value="20">20 items</option>
<option value="50">50 items</option>
<option value="100">100 items</option>
<option value="200">200 items</option>
</select>
</div>
<div>
<input type="checkbox" id="saved-search-send-if-no-result" class="saved-search-send-if-no-result" name="saved-search-send-if-no-result">
<label for="saved-search-send-if-no-result" class="action-panel-label smaller-checkbox">
Send even when there aren't any new results
</label>
</div>
<div class="action-panel-control-wrap option-text-in-email-wrap">
<label for="saved-search-email-text" class="action-panel-label">
Optional text in email:
</label>
<textarea name="saved-search-email-text"
id="saved-search-email-text"
class="saved-search-email-text"></textarea>
</div>
</div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Saving..."
data-ga-category="save_share"
data-ga-action="alert"
data-ga-label="save">
Save
</button>
<button class="action-panel-cancel"
aria-label="Close 'Your saved search' panel"
ref="linksrc=close_saved_search_panel"
aria-controls="saved-search-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="alert"
data-ga-label="cancel">
Cancel
</button>
</div>
</form>
</div>
</div>
<div id="citation-manager-action-panel" class="citation-manager-action-panel action-panel" aria-hidden="true">
<div class="inner-wrap">
<h2 class="action-panel-heading">
Create a file for external citation management software
</h2>
<form id="citation-manager-action-panel-form"
class="action-panel-content action-form"
action="/results-export-ids/"
data-by-search-action="/results-export-search-data/"
data-by-ids-action="/results-export-ids/"
method="post"
data-by-search-method="post"
data-by-ids-method="post">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<input name="results-format" type="hidden" value="pubmed"/>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Sending..."
data-ga-category="save_share"
data-ga-action="citation_manager"
data-ga-label="save">
Create file
</button>
<button class="action-panel-cancel"
aria-label="Close 'Send citations to citation manager' panel"
ref="linksrc=close_citation_manager_panel"
aria-controls="citation-manager-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="citation_manager"
data-ga-label="cancel">
Cancel
</button>
</div>
</form>
</div>
</div>
<div id="rss-action-panel" class="rss-action-panel action-panel " aria-hidden="true">
<div class="inner-wrap">
<h2 class="action-panel-heading">
Your RSS Feed
</h2>
<form id="rss-action-panel-form"
class="rss-action-panel-form action-panel-content action-form"
data-create-rss-feed-url="/create-rss-feed-url/"
data-search-form-term-value="">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<div class="action-panel-control-wrap">
<label for="rss-name" class="action-panel-label required-field-asterisk">
Name of RSS Feed:
</label>
<input maxlength="200"
placeholder="Name"
type="text"
name="rss-name"
id="rss-name"
class="rss-name"
value=''
required
pattern="[^&quot;&amp;=&lt;&gt;\/]*" title="The following characters are not allowed in the Name field: &quot;&amp;=&lt;&gt;/">
</div>
<div class="rss-limit-wrap">
<div class="action-panel-control-wrap action-panel-extra-margin-top">
<label for="rss-limit" class="action-panel-label">
Number of items displayed:
</label>
<select id="rss-limit" class="no-border-panel-selector rss-limit">
<option value="5">5</option>
<option value="10">10</option>
<option value="15" selected="selected">15</option>
<option value="20">20</option>
<option value="50">50</option>
<option value="100">100</option>
</select>
</div>
</div>
<div class="action-panel-actions">
<button class="action-panel-submit"
type="submit"
data-loading-label="Creating..."
data-ga-category="save_share"
data-ga-action="alert"
data-ga-label="save">
Create RSS
</button>
<button class="action-panel-cancel"
aria-label="Close 'Your RSS' panel"
ref="linksrc=close_rss_panel"
aria-controls="rss-action-panel"
aria-expanded="false"
data-ga-category="save_share"
data-ga-action="alert"
data-ga-label="cancel">
Cancel
</button>
</div>
<div class="action-panel-control-wrap rss-link-copy-wrap">
<label for="rss-link" class="usa-sr-only">RSS Link</label>
<input placeholder="Your RSS Feed Link" type="text" name="rss-link" id="rss-link" class="rss-link" title="RSS Link">
<button
type="button"
disabled
class="rss-link-copy-button disabled"
data-ga-category="save_share"
data-ga-action="rss"
data-ga-label="copy">
Copy
</button>
</div>
</form>
</div>
</div>
</div>
</div>
<div class="article-page" id="article-page" data-article-pmid="1878827">
<aside class="page-sidebar">
<div class="inner-wrap">
<div class="full-text-links">
<div class="full-view">
<h3 class="title">
Full text links
</h3>
<div class="full-text-links-list">
<a class="link-item
pmc
dialog-focus"
href="https://pmc.ncbi.nlm.nih.gov/articles/pmid/1878827/"
target="_blank"
rel="noopener"
ref="linksrc=fulltextorjournal_fulltext&amp;is_pmc=True&amp;PrId=3494&amp;itool=Abstract-def&amp;log$=linkouticon&amp;uid=1878827&amp;db=pubmed&amp;nlmid=9711805"
title="Free full text at PubMed Central"
data-ga-category="full_text"
data-ga-action="PMC"
data-ga-label="1878827"
><span class="text">
Free PMC article
</span></a>
</div>
</div>
<div class="short-view">
<a href="#" class="full-text-links-button full-text-links-dialog-trigger">
Full text links
</a>
</div>
</div>
<div class="actions-buttons sidebar"><h3 class="title">Actions</h3><div class="inner-wrap"><button class="citation-button citation-dialog-trigger"
aria-label="Open dialog with citation text in different styles"
data-ga-category="save_share"
data-ga-action="cite"
data-ga-label="open"
data-all-citations-url="/1878827/citations/"
data-citation-style="nlm"
data-pubmed-format-link="/1878827/export/"><span class="button-label">Cite</span></button><link type="text/css" href="ncbi-overlay-block/src/overlay-block.css"><div class="collections-button-container" data-article-id="1878827" data-article-db="pubmed"><button class="collections-button collections-dialog-trigger"
aria-label="Save article in MyNCBI collections."
data-ga-category="collections_button"
data-ga-action="click"
data-ga-label="collections_button"
data-collections-open-dialog-enabled="false"
data-collections-open-dialog-url="https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F%23open-collections-dialog"
data-in-collections="false"><span class="button-label">Collections</span></button><div class="overlay" role="dialog"><div id="collections-action-dialog"
class="dialog collections-dialog"
aria-hidden="true"><div class="title">Add to Collections</div><div class="collections-action-panel action-panel"><form id="collections-action-dialog-form"
class="collections-action-panel-form action-panel-content action-form action-panel-smaller-selectors"
data-existing-collections-url="/list-existing-collections/"
data-add-to-existing-collection-url="/add-to-existing-collection/"
data-create-and-add-to-new-collection-url="/create-and-add-to-new-collection/"
data-myncbi-max-collection-name-length="100"
data-collections-root-url="https://www.ncbi.nlm.nih.gov/myncbi/collections/"><input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc"><div class="choice-group" role="radiogroup"><ul class="radio-group-items"><li><input type="radio"
id="collections-action-dialog-new"
class="collections-new"
name="collections"
value="new"
data-ga-category="collections_button"
data-ga-action="click"
data-ga-label="collections_radio_new"><label for="collections-action-dialog-new">Create a new collection</label></li><li><input type="radio"
id="collections-action-dialog-existing"
class="collections-existing"
name="collections"
value="existing"
checked="true"
data-ga-category="collections_button"
data-ga-action="click"
data-ga-label="collections_radio_existing"><label for="collections-action-dialog-existing">Add to an existing collection</label></li></ul></div><div class="controls-wrapper"><div class="action-panel-control-wrap new-collections-controls"><label for="collections-action-dialog-add-to-new" class="action-panel-label required-field-asterisk">
Name your collection:
</label><input
type="text"
name="add-to-new-collection"
id="collections-action-dialog-add-to-new"
class="collections-action-add-to-new"
pattern="[^&quot;&amp;=&lt;&gt;\/]*" title="The following characters are not allowed in the Name field: &quot;&amp;=&lt;&gt;/"
maxlength="100"
data-ga-category="collections_button"
data-ga-action="create_collection"
data-ga-label="non_favorties_collection"><div class="collections-new-name-too-long usa-input-error-message selection-validation-message">
Name must be less than 100 characters
</div></div><div class="action-panel-control-wrap existing-collections-controls"><label for="collections-action-dialog-add-to-existing" class="action-panel-label">
Choose a collection:
</label><select id="collections-action-dialog-add-to-existing"
class="action-panel-selector collections-action-add-to-existing"
data-ga-category="collections_button"
data-ga-action="select_collection"
data-ga-label="($('.collections-action-add-to-existing').val() === 'Favorites') ? 'Favorites' : 'non_favorites_collection'"></select><div class="collections-retry-load-on-error usa-input-error-message selection-validation-message">
Unable to load your collection due to an error<br><a href="#">Please try again</a></div></div></div><div class="action-panel-actions"><button class="action-panel-submit"
type="submit"
data-loading-label="Adding..."
data-pinger-ignore
data-ga-category="collections_button"
data-ga-action="click"
data-ga-label="add">
Add
</button><button class="action-panel-cancel"
aria-label="Close 'Add to Collections' panel"
ref="linksrc=close_collections_panel"
aria-controls="collections-action-panel"
aria-expanded="false"
data-ga-category="collections_button"
data-ga-action="click"
data-ga-label="cancel">
Cancel
</button></div></form></div></div></div></div><button class="more-actions-button more-actions-dialog-trigger"
title="Open dialog with more actions to take"
ref="linksrc=more_actions_btn"></button><div class="display-options" data-format-key="format"
data-default-format-value="abstract"
data-current-format-value="abstract" role="region"><button
class="trigger usa-button"
title="Change format"
data-ga-category="display_options"
data-ga-action="display_options_dialog"><span class="button-label">Display options</span></button><div class="dropdown" hidden><div class="title">
Display options
</div><div class="content"><div class="format-container"><span class="option-label">
Format
</span><select name="format" data-initial-value="abstract" aria-label="Display format" id="sidebar-actions-display-format"><option value="abstract">Abstract</option><option value="pubmed">PubMed</option><option value="pmid">PMID</option></select></div></div></div></div></div></div>
<div class="social-sharing">
<h3 class="title">
Share
</h3>
<ul class="social-sharing-links usa-unstyled-list">
<li>
<a href="http://twitter.com/intent/tweet?text=Comparison%20of%20search%20strategies%20on%20CD%20Plus/MEDLINE%20https%3A//pubmed.ncbi.nlm.nih.gov/1878827/"
class="share-link share-link-twitter"
rel="noreferrer noopener"
target="Pubmed-Social-Media-Share-Popup"
title="Share article on Twitter"
data-ga-category="save_share"
data-ga-action="social"
data-ga-label="twitter"></a>
</li>
<li>
<a href="http://www.facebook.com/sharer/sharer.php?u=https%3A//pubmed.ncbi.nlm.nih.gov/1878827/"
class="share-link share-link-facebook"
rel="noreferrer noopener"
target="Pubmed-Social-Media-Share-Popup"
title="Share article on Facebook"
data-ga-category="save_share"
data-ga-action="social"
data-ga-label="fb"></a>
</li>
<li>
<div class="share-permalink">
<button class="trigger"
title="Show article permalink"
ref="linksrc=show_permalink_btn">
</button>
<div class="dropdown" hidden>
<div class="title">
Permalink
</div>
<div class="content">
<input type="text"
class="permalink-text"
value="https://pubmed.ncbi.nlm.nih.gov/1878827/"
aria-label="Article permalink"/><button class="permalink-copy-button usa-button-primary"
title="Copy article permalink"
data-ga-category="save_share"
data-ga-action="link"
data-ga-label="copy_link"><span class="button-title">Copy</span></button>
</div>
</div>
</div>
</li>
</ul>
</div>
<nav class="page-navigator" role="navigation" aria-label="Page navigation">
<div class="full-view">
<h3 class="title">
Page navigation
</h3>
<ul class="items-list">
<li class="heading ">
<a href="#heading"
aria-label="navigate to Title &amp; authors section"
data-ga-category="page_nav"
data-ga-action="heading">
Title &amp; authors
</a>
</li>
<li class="abstract ">
<a href="#abstract"
aria-label="navigate to Abstract section"
data-ga-category="page_nav"
data-ga-action="abstract">
Abstract
</a>
</li>
<li class="linked-commentary current">
<a href="#linked-commentary"
aria-label="navigate to Comment in section"
data-ga-category="page_nav"
data-ga-action="linked-commentary">
Comment in
</a>
</li>
<li class="similar ">
<a href="#similar"
aria-label="navigate to Similar articles section"
data-ga-category="page_nav"
data-ga-action="similar">
Similar articles
</a>
</li>
<li class="references ">
<a href="#references"
aria-label="navigate to References section"
data-ga-category="page_nav"
data-ga-action="references">
References
</a>
</li>
<li class="publication-types ">
<a href="#publication-types"
aria-label="navigate to Publication types section"
data-ga-category="page_nav"
data-ga-action="publication-types">
Publication types
</a>
</li>
<li class="mesh-terms ">
<a href="#mesh-terms"
aria-label="navigate to MeSH terms section"
data-ga-category="page_nav"
data-ga-action="mesh-terms">
MeSH terms
</a>
</li>
<li class="linkout ">
<a href="#linkout"
aria-label="navigate to LinkOut - more resources section"
data-ga-category="page_nav"
data-ga-action="linkout">
LinkOut - more resources
</a>
</li>
</ul>
</div>
<select class="short-view" autocomplete="off" title="navigate to selected section" aria-label="Navigate to page section">
<option value="heading">Title &amp; authors</option>
<option value="abstract">Abstract</option>
<option value="linked-commentary">Comment in</option>
<option value="similar">Similar articles</option>
<option value="references">References</option>
<option value="publication-types">Publication types</option>
<option value="mesh-terms">MeSH terms</option>
<option value="linkout">LinkOut - more resources</option>
</select>
</nav>
</div>
</aside>
<main class="article-details" id="article-details">
<!-- "Filters applied" shows only when page is redirected from search -->
<!-- because search found one result -->
<header class="heading" id="heading">
<div class="full-view" id="full-view-heading">
<div class="article-citation">
<div class="article-source">
<div class="journal-actions dropdown-block"><button id="full-view-journal-trigger"
class="journal-actions-trigger trigger"
ref="linksrc=journal_actions_btn"
title="CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"
tabindex="0"
aria-controls="full-view-journal"
aria-expanded="false"
aria-label="Toggle dropdown menu for journal CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"
data-pinger-ignore>
CMAJ
</button><div id="full-view-journal"
class="journal-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for journal CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"><div class="title">Actions</div><div class="content"><ul class="journal-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22CMAJ%22%5Bjour%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22CMAJ%22%5Bjour%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_journal_name_link&amp;journal_abbrev=CMAJ"
data-ga-category="search"
data-ga-action="journal_link"
data-ga-label="CMAJ">
Search in PubMed
</a></li><li><a class="search-in-nlm-catalog-link dropdown-block-link"
ref ="linksrc=search_in_nlm_catalog_link"
href="https://www.ncbi.nlm.nih.gov/nlmcatalog?term=%22CMAJ%22%5BTitle+Abbreviation%5D"
data-ga-category="search_catalog"
data-ga-action="journal_link"
data-ga-label="CMAJ">
Search in NLM Catalog
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref ="linksrc=add_to_search_link"
role="button"
data-search-term='"CMAJ"[jour]'
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label='"CMAJ"[jour]'
href="#">
Add to Search
</a></li></ul></div></div></div><span class="period">. </span><span class="cit">1991 Sep 1;145(5):457-64.</span>
</div>
</div>
<h1 class="heading-title">
Comparison of search strategies on CD Plus/MEDLINE
</h1>
<div class="inline-authors">
<div class="authors">
<div class="authors-list">
<span class="authors-list-item "><a class="full-name"
href="/?term=Wright+LC&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="L C Wright">L C Wright</a><sup class="affiliation-links"><span class="author-sup-separator">&nbsp;</span><a class="affiliation-link" title="Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto." href="#full-view-affiliation-1" ref="linksrc=author_aff">
1
</a></sup><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Sutherland+HJ&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="H J Sutherland">H J Sutherland</a><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Jackson+JI&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="J I Jackson">J I Jackson</a><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Till+JE&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="J E Till">J E Till</a></span>
</div>
</div>
</div>
<div class="short-article-details">
Affiliations
<button
class="more-details"
id="toggle-authors"
data-alt-text="Collapse"
aria-controls="expanded-authors"
aria-expanded="false"
data-pinger-ignore
data-fetch-url="/1878827/long-authors/"
data-id-prefix="">
<span class="title">
Expand
</span>
</button>
</div>
<div class="extended-article-details" id="expanded-authors" aria-hidden="true">
<div class="expanded-authors" id="full-view-expanded-authors">
<div class="affiliations">
<h3 class="title">
Affiliation
</h3>
<ul class="item-list">
<li data-affiliation-id="full-view-affiliation-1"
id="full-view-affiliation-1"
><sup class="key">1</sup> Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto.</li>
</ul>
</div>
</div>
</div>
<ul class="identifiers" id="full-view-identifiers">
<li>
<span class="identifier pubmed">
<span class="id-label">
PMID:
</span>
<strong class="current-id" title="PubMed ID">1878827</strong>
</span>
</li>
<li>
<span class="identifier pmc">
<span class="id-label">
PMCID:
</span>
<a class="id-link"
target="_blank"
rel="noopener"
ref="linksrc=article_id_link&amp;article_id=PMC1335828&amp;id_type=PMC"
href="https://pmc.ncbi.nlm.nih.gov/articles/PMC1335828/"
data-ga-category="full_text"
data-ga-action="PMCID"
>
PMC1335828
</a>
</span>
</li>
</ul>
<div class="in-clipboard-label " hidden>
Item in Clipboard
</div>
</div>
<div class="short-view" id="short-view-heading">
<h1 class="heading-title">
Comparison of search strategies on CD Plus/MEDLINE
</h1>
<div class="short-citation">
<span class="authors-list">
<span class="authors-list-item "><span class="full-name">L C Wright</span><span class="citation-separator">&nbsp;et al.</span></span>
</span>
<span class="citation-journal">
CMAJ<span class="citation-separator">.</span>
</span>
<span class="date">
<time class="citation-year" datetime="1991">1991</time><span class="citation-separator">.</span>
</span>
</div>
<div class="more-article-details-section with-display-settings">
<button class="more-article-details"
id="toggle-article-details"
data-alt-text="Hide details"
ref="linksrc=toggle_article_details"
aria-controls="full-article-details"
aria-expanded="false"
data-fetch-url="/1878827/long-authors/"
data-id-prefix="">
<span class="title">Show details</span>
</button>
<div class="display-options" data-format-key="format"
data-default-format-value="abstract"
data-current-format-value="abstract" role="region">
<button
class="trigger usa-button"
title="Change format"
data-ga-category="display_options"
data-ga-action="display_options_dialog">
<span class="button-label">Display options</span>
</button>
<div class="dropdown" hidden>
<div class="title">
Display options
</div>
<div class="content">
<div class="format-container">
<span class="option-label">
Format
</span>
<select name="format" data-initial-value="abstract" aria-label="Display format" id="mobile-display-format">
<option value="abstract">Abstract</option>
<option value="pubmed">PubMed</option>
<option value="pmid">PMID</option>
</select>
</div>
</div>
</div>
</div>
</div>
<div class="extended-article-details" id="full-article-details" aria-hidden="true">
<div class="article-citation">
<div class="article-source">
<div class="journal-actions dropdown-block"><button id="short-view-journal-trigger"
class="journal-actions-trigger trigger"
ref="linksrc=journal_actions_btn"
title="CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"
tabindex="0"
aria-controls="short-view-journal"
aria-expanded="false"
aria-label="Toggle dropdown menu for journal CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"
data-pinger-ignore>
CMAJ
</button><div id="short-view-journal"
class="journal-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for journal CMAJ : Canadian Medical Association journal = journal de l&#x27;Association medicale canadienne"><div class="title">Actions</div><div class="content"><ul class="journal-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22CMAJ%22%5Bjour%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22CMAJ%22%5Bjour%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_journal_name_link&amp;journal_abbrev=CMAJ"
data-ga-category="search"
data-ga-action="journal_link"
data-ga-label="CMAJ">
Search in PubMed
</a></li><li><a class="search-in-nlm-catalog-link dropdown-block-link"
ref ="linksrc=search_in_nlm_catalog_link"
href="https://www.ncbi.nlm.nih.gov/nlmcatalog?term=%22CMAJ%22%5BTitle+Abbreviation%5D"
data-ga-category="search_catalog"
data-ga-action="journal_link"
data-ga-label="CMAJ">
Search in NLM Catalog
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref ="linksrc=add_to_search_link"
role="button"
data-search-term='"CMAJ"[jour]'
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label='"CMAJ"[jour]'
href="#">
Add to Search
</a></li></ul></div></div></div><span class="period">. </span><span class="cit">1991 Sep 1;145(5):457-64.</span>
</div>
</div>
<div class="expanded-authors" id="short-view-expanded-authors">
<div class="authors">
<h3 class="title">
Authors
</h3>
<div class="authors-list">
<span class="authors-list-item "><a class="full-name"
href="/?term=Wright+LC&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="L C Wright">L C Wright</a><sup class="affiliation-links"><span class="author-sup-separator">&nbsp;</span><a class="affiliation-link" title="Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto." href="#short-view-affiliation-1" ref="linksrc=author_aff">
1
</a></sup><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Sutherland+HJ&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="H J Sutherland">H J Sutherland</a><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Jackson+JI&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="J I Jackson">J I Jackson</a><span class="comma">,&nbsp;</span></span><span class="authors-list-item "><a class="full-name"
href="/?term=Till+JE&amp;cauthor_id=1878827"
ref="linksrc=author_name_link"
data-ga-category="search"
data-ga-action="author_link"
data-ga-label="J E Till">J E Till</a></span>
</div>
</div>
<div class="affiliations">
<h3 class="title">
Affiliation
</h3>
<ul class="item-list">
<li data-affiliation-id="short-view-affiliation-1"
id="short-view-affiliation-1"
><sup class="key">1</sup> Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto.</li>
</ul>
</div>
</div>
<ul class="identifiers" id="short-view-identifiers">
<li>
<span class="identifier pubmed">
<span class="id-label">
PMID:
</span>
<strong class="current-id" title="PubMed ID">1878827</strong>
</span>
</li>
<li>
<span class="identifier pmc">
<span class="id-label">
PMCID:
</span>
<a class="id-link"
target="_blank"
rel="noopener"
ref="linksrc=article_id_link&amp;article_id=PMC1335828&amp;id_type=PMC"
href="https://pmc.ncbi.nlm.nih.gov/articles/PMC1335828/"
data-ga-category="full_text"
data-ga-action="PMCID"
>
PMC1335828
</a>
</span>
</li>
</ul>
<div class="in-clipboard-label " hidden>
Item in Clipboard
</div>
</div>
</div>
</header>
<div class="actions-buttons inline"><div class="inner-wrap"><button class="full-text-links-button full-text-links-dialog-trigger"
title="Open dialog with full text links"
ref="linksrc=full_text_links">
Full text links
</button><button class="citation-button citation-dialog-trigger"
aria-label="Open dialog with citation text in different styles"
data-ga-category="save_share"
data-ga-action="cite"
data-ga-label="open"
data-all-citations-url="/1878827/citations/"
data-citation-style="nlm"
data-pubmed-format-link="/1878827/export/"><span class="button-label">Cite</span></button><button class="more-actions-button more-actions-dialog-trigger"
title="Open dialog with more actions to take"
ref="linksrc=more_actions_btn"></button><div class="display-options" data-format-key="format"
data-default-format-value="abstract"
data-current-format-value="abstract" role="region"><button
class="trigger usa-button"
title="Change format"
data-ga-category="display_options"
data-ga-action="display_options_dialog"><span class="button-label">Display options</span></button><div class="dropdown" hidden><div class="title">
Display options
</div><div class="content"><div class="format-container"><span class="option-label">
Format
</span><select name="format" data-initial-value="abstract" aria-label="Display format" id="inline-actions-display-format"><option value="abstract">Abstract</option><option value="pubmed">PubMed</option><option value="pmid">PMID</option></select></div></div></div></div></div></div>
<div class="abstract" id="abstract">
<h2 class="title">
Abstract
</h2>
<div class="abstract-content selected"
id="eng-abstract">
<p>
<strong class="sub-title">
Objective:
</strong>
To compare two strategies for searching MEDLINE using the CD Plus/MEDLINE program on compact disc.
</p>
<p>
<strong class="sub-title">
Design:
</strong>
Comparison study.
</p>
<p>
<strong class="sub-title">
Interventions:
</strong>
Two search strategies were designed and executed for each of two topics (patient recruitment to clinical trials and attitudes of patients, the public and health care professionals toward clinical trials). Strategy A: searches based on key words selected from the medical subject heading (MeSH) tree structure. Strategy B: searches based on MeSH terms most frequently used to index a known set of relevant articles. Defined search restrictions were then applied. The effects of the restrictions on the absolute number of citations retrieved and on the proportion of relevant citations were assessed.
</p>
<p>
<strong class="sub-title">
Outcome measures:
</strong>
Number of articles retrieved, number of relevant articles, precision and recall of each search strategy and overlap between strategies.
</p>
<p>
<strong class="sub-title">
Main results:
</strong>
Strategy A produced more citations than strategy B (recruitment 147 v. 38, attitude 366 v. 57) but had more inappropriate citations (recruitment 75 v. 17, attitude 265 v. 25). Both strategies produced 73 relevant recruitment citations and 101 relevant attitude citations. In the recruitment search although the precision did not differ significantly between strategies A and B the difference in recall was significant (98.6% v. 28.8% respectively, p less than 0.0001). In the attitude search strategy A had a lower precision than strategy B (27.6% v. 56.1%, p less than 0.0001) but a much higher recall (100% v. 31.7%, p less than 0.0001).
</p>
<p>
<strong class="sub-title">
Conclusions:
</strong>
Strategy A would be more valuable to researchers doing extensive reviews, whereas strategy B would be useful for the busy clinician who simply wants a few appropriate references quickly and is willing to sacrifice comprehensive retrieval in the interest of efficiency.
</p>
</div>
</div>
<p class="disclaimer" id="disclaimer">
<a href="/disclaimer/" target="_blank" data-ga-category="literature_resources"
data-ga-action="disclaimer_link" data-ga-label="under_abstract">PubMed Disclaimer</a>
</p>
<div class="linked-articles" id="linked-commentary">
<h2 class="title">
Comment in
</h2>
<ul class="item-list usa-unstyled-list">
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/1735025/"
ref="article_id=1735025&amp;linksrc=comments_link"
data-ga-category="comment_correction"
data-ga-action="abstract_page_link"
data-ga-label="linked-commentary">
Comparison of search strategies on CD Plus/MEDLINE.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Gannon RP.</span>
<span class="docsum-authors short-authors">Gannon RP.</span>
<span class="docsum-journal-citation full-journal-citation">CMAJ. 1992 Jan 15;146(2):100-1.</span>
<span class="docsum-journal-citation short-journal-citation">CMAJ. 1992.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">1735025</span></span>
<span class="free-resources spaced-citation-item citation-part">Free PMC article.</span>
<span class="no-abstract spaced-citation-item citation-part">No abstract available.</span>
</div>
</div>
</li>
</ul>
</div>
<div class="similar-articles" id="similar">
<h2 class="title">
Similar articles
</h2>
<ul class="articles-list" id="similar-articles-list">
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/16980145/"
ref="article_id=16980145&amp;linksrc=similar_articles_link&amp;ordinalpos=1"
data-ga-category="similar_article"
data-ga-action="16980145"
data-ga-label="">
Errors in search strategies were identified by type and frequency.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Sampson M, McGowan J.</span>
<span class="docsum-authors short-authors">Sampson M, et al.</span>
<span class="docsum-journal-citation full-journal-citation">J Clin Epidemiol. 2006 Oct;59(10):1057-63. doi: 10.1016/j.jclinepi.2006.01.007. Epub 2006 Jun 23.</span>
<span class="docsum-journal-citation short-journal-citation">J Clin Epidemiol. 2006.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">16980145</span></span>
</div>
</div>
</li>
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/16880424/"
ref="article_id=16880424&amp;linksrc=similar_articles_link&amp;ordinalpos=2"
data-ga-category="similar_article"
data-ga-action="16880424"
data-ga-label="">
Search strategies for retrieving complementary and alternative medicine clinical trials in oncology.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Bardia A, Wahner-Roedler DL, Erwin PL, Sood A.</span>
<span class="docsum-authors short-authors">Bardia A, et al.</span>
<span class="docsum-journal-citation full-journal-citation">Integr Cancer Ther. 2006 Sep;5(3):202-5. doi: 10.1177/1534735406292146.</span>
<span class="docsum-journal-citation short-journal-citation">Integr Cancer Ther. 2006.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">16880424</span></span>
</div>
</div>
</li>
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/8428194/"
ref="article_id=8428194&amp;linksrc=similar_articles_link&amp;ordinalpos=3"
data-ga-category="similar_article"
data-ga-action="8428194"
data-ga-label="">
A comparison of MEDLINE CD-ROM and librarian-mediated search service users.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Seago BL, Campbell FM.</span>
<span class="docsum-authors short-authors">Seago BL, et al.</span>
<span class="docsum-journal-citation full-journal-citation">Bull Med Libr Assoc. 1993 Jan;81(1):63-6.</span>
<span class="docsum-journal-citation short-journal-citation">Bull Med Libr Assoc. 1993.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">8428194</span></span>
<span class="free-resources spaced-citation-item citation-part">Free PMC article.</span>
</div>
</div>
</li>
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/10507188/"
ref="article_id=10507188&amp;linksrc=similar_articles_link&amp;ordinalpos=4"
data-ga-category="similar_article"
data-ga-action="10507188"
data-ga-label="">
The art and science of searching MEDLINE to answer clinical questions. Finding the right number of articles.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Allison JJ, Kiefe CI, Weissman NW, Carter J, Centor RM.</span>
<span class="docsum-authors short-authors">Allison JJ, et al.</span>
<span class="docsum-journal-citation full-journal-citation">Int J Technol Assess Health Care. 1999 Spring;15(2):281-96.</span>
<span class="docsum-journal-citation short-journal-citation">Int J Technol Assess Health Care. 1999.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">10507188</span></span>
<span class="publication-type spaced-citation-item citation-part">Review.</span>
</div>
</div>
</li>
<li class="full-docsum">
<div class="docsum-content" style="display:inline;">
<a class="docsum-title"
href="/10122123/"
ref="article_id=10122123&amp;linksrc=similar_articles_link&amp;ordinalpos=5"
data-ga-category="similar_article"
data-ga-action="10122123"
data-ga-label="">
MEDLINE and MeSH: challenges for end users.
</a>
<div class="docsum-citation full-citation">
<span class="docsum-authors full-authors">Delozier EP, Lingle VA.</span>
<span class="docsum-authors short-authors">Delozier EP, et al.</span>
<span class="docsum-journal-citation full-journal-citation">Med Ref Serv Q. 1992 Fall;11(3):29-46. doi: 10.1300/J115V11N03_03.</span>
<span class="docsum-journal-citation short-journal-citation">Med Ref Serv Q. 1992.</span>
<span class="citation-part">PMID: <span class="docsum-pmid">10122123</span></span>
<span class="publication-type spaced-citation-item citation-part">Review.</span>
</div>
</div>
</li>
</ul>
<div class="actions-bar">
<a
class="show-all-linked-articles"
data-href="/?linkname=pubmed_pubmed&from_uid=1878827"
data-ga-category="similar_article"
data-ga-action="show_all"
>
See all similar articles
</a>
</div>
</div>
<div class="references" id="references">
<h2 class="title">
References
</h2>
<div id='top-references-list' class="references-lists-container">
<div class="refs-list">
<ol id="top-references-list-1" class="references-list">
<li>
<ol class="references-and-notes-list">
<li
class="skip-numbering"
value="1">
Ann Intern Med. 1985 Nov;103(5):812-6
-
<a
class="reference-link"
href="/3901853/"
ref="linksrc=references_link&amp;ordinalpos=1"
data-ga-category="reference"
data-ga-action="3901853"
>
PubMed
</a>
</li>
</ol>
</li>
<li>
<ol class="references-and-notes-list">
<li
class="skip-numbering"
value="1">
JAMA. 1979 Jan 26;241(4):387-90
-
<a
class="reference-link"
href="/364084/"
ref="linksrc=references_link&amp;ordinalpos=1"
data-ga-category="reference"
data-ga-action="364084"
>
PubMed
</a>
</li>
</ol>
</li>
<li>
<ol class="references-and-notes-list">
<li
class="skip-numbering"
value="1">
N Engl J Med. 1981 Oct 15;305(16):924-30
-
<a
class="reference-link"
href="/7024808/"
ref="linksrc=references_link&amp;ordinalpos=1"
data-ga-category="reference"
data-ga-action="7024808"
>
PubMed
</a>
</li>
</ol>
</li>
<li>
<ol class="references-and-notes-list">
<li
class="skip-numbering"
value="1">
JAMA. 1983 Nov 11;250(18):2494-9
-
<a
class="reference-link"
href="/6355532/"
ref="linksrc=references_link&amp;ordinalpos=1"
data-ga-category="reference"
data-ga-action="6355532"
>
PubMed
</a>
</li>
</ol>
</li>
<li>
<ol class="references-and-notes-list">
<li
class="skip-numbering"
value="1">
Ann Intern Med. 1990 Jan 1;112(1):78-84
-
<a
class="reference-link"
href="/2403476/"
ref="linksrc=references_link&amp;ordinalpos=1"
data-ga-category="reference"
data-ga-action="2403476"
>
PubMed
</a>
</li>
</ol>
</li>
</ol>
<div class="actions-bar">
<button
class="show-all"
ref="linksrc=show_all_references_link"
aria-controls="top-references-list-1"
data-next-page-url="/1878827/references/"
data-ga-category="reference"
data-ga-action="show_more"
>
Show all 10 references
</button>
</div>
</div>
</div>
</div>
<div id="publication-types" class="publication-types keywords-section">
<h2 class="title">
Publication types
</h2>
<ul class="keywords-list"><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link"
aria-label="Toggle dropdown menu for keyword Research Support, Non-U.S. Gov&#x27;t"
tabindex="0"
aria-controls="keyword-actions-publication-types-0"
aria-expanded="false"
data-pinger-ignore>
Research Support, Non-U.S. Gov&#x27;t
</button><div id="keyword-actions-publication-types-0"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword Research Support, Non-U.S. Gov&#x27;t"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22Research+Support%2C+Non-U.S.+Gov%27t%22%5Bpt%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22Research+Support%2C+Non-U.S.+Gov%27t%22%5Bpt%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;keyword=&quot;Research Support, Non-U.S. Gov&#x27;t&quot;[pt]"
data-ga-category="search"
data-ga-action="pub_type"
data-ga-label="Research Support, Non-U.S. Gov&#x27;t">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=Research+Support%2C+Non-U.S.+Gov%27t"
data-ga-category="search_mesh"
data-ga-action="pub_type_link"
data-ga-label="Research Support, Non-U.S. Gov&#x27;t">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;Research Support, Non-U.S. Gov&#x27;t&quot;[pt]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;Research Support, Non-U.S. Gov&#x27;t&quot;[pt]"
href="#">
Add to Search
</a></li></ul></div></div></div></li></ul>
</div>
<div id="mesh-terms" class="mesh-terms keywords-section">
<h2 class="title">
MeSH terms
</h2>
<ul class="keywords-list"><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link major"
aria-label="Toggle dropdown menu for keyword Algorithms*"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-major-0"
aria-expanded="false"
data-pinger-ignore>
Algorithms*
</button><div id="keyword-actions-mesh-terms-major-0"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword Algorithms*"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22Algorithms%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22Algorithms%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;Algorithms&quot;[MAJR]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="Algorithms*">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=Algorithms"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="Algorithms*">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;Algorithms&quot;[MAJR]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;Algorithms&quot;[MAJR]"
href="#">
Add to Search
</a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link major"
aria-label="Toggle dropdown menu for keyword CD-ROM*"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-major-1"
aria-expanded="false"
data-pinger-ignore>
CD-ROM*
</button><div id="keyword-actions-mesh-terms-major-1"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword CD-ROM*"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22CD-ROM%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22CD-ROM%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;CD-ROM&quot;[MAJR]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="CD-ROM*">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=CD-ROM"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="CD-ROM*">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;CD-ROM&quot;[MAJR]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;CD-ROM&quot;[MAJR]"
href="#">
Add to Search
</a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link"
aria-label="Toggle dropdown menu for keyword Evaluation Studies as Topic"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-2"
aria-expanded="false"
data-pinger-ignore>
Evaluation Studies as Topic
</button><div id="keyword-actions-mesh-terms-2"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword Evaluation Studies as Topic"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22Evaluation+Studies+as+Topic%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22Evaluation+Studies+as+Topic%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;Evaluation Studies as Topic&quot;[MeSH]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="Evaluation Studies as Topic">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=Evaluation+Studies+as+Topic"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="Evaluation Studies as Topic">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;Evaluation Studies as Topic&quot;[MeSH]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;Evaluation Studies as Topic&quot;[MeSH]"
href="#">
Add to Search
</a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link major"
aria-label="Toggle dropdown menu for keyword Information Storage and Retrieval*"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-major-3"
aria-expanded="false"
data-pinger-ignore>
Information Storage and Retrieval*
</button><div id="keyword-actions-mesh-terms-major-3"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword Information Storage and Retrieval*"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22Information+Storage+and+Retrieval%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22Information+Storage+and+Retrieval%22%5BMAJR%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;Information Storage and Retrieval&quot;[MAJR]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="Information Storage and Retrieval*">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=Information+Storage+and+Retrieval"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="Information Storage and Retrieval*">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;Information Storage and Retrieval&quot;[MAJR]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;Information Storage and Retrieval&quot;[MAJR]"
href="#">
Add to Search
</a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link"
aria-label="Toggle dropdown menu for keyword MEDLINE"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-4"
aria-expanded="false"
data-pinger-ignore>
MEDLINE
</button><div id="keyword-actions-mesh-terms-4"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword MEDLINE"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22MEDLINE%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22MEDLINE%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;MEDLINE&quot;[MeSH]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="MEDLINE">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=MEDLINE"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="MEDLINE">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;MEDLINE&quot;[MeSH]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;MEDLINE&quot;[MeSH]"
href="#">
Add to Search
</a></li></ul></div></div></div></li><li><div class="keyword-actions dropdown-block"><button class="keyword-actions-trigger trigger keyword-link"
aria-label="Toggle dropdown menu for keyword Surveys and Questionnaires"
tabindex="0"
aria-controls="keyword-actions-mesh-terms-5"
aria-expanded="false"
data-pinger-ignore>
Surveys and Questionnaires
</button><div id="keyword-actions-mesh-terms-5"
class="keyword-actions-dropdown dropdown dropdown-container"
hidden
aria-label="Dropdown menu for keyword Surveys and Questionnaires"><div class="title">Actions</div><div class="content"><ul class="keyword-actions-links"><li><a class="search-in-pubmed-link dropdown-block-link"
href="/?term=%22Surveys+and+Questionnaires%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
data-href="/?term=%22Surveys+and+Questionnaires%22%5BMeSH%5D&amp;sort=date&amp;sort_order=desc"
ref="linksrc=search_in_pubmed_keyword_link&amp;mesh=&quot;Surveys and Questionnaires&quot;[MeSH]"
data-ga-category="search"
data-ga-action="mesh_term"
data-ga-label="Surveys and Questionnaires">
Search in PubMed
</a></li><li><a class="search-in-mesh-link dropdown-block-link"
ref="linksrc=search_in_mesh_link"
href="https://www.ncbi.nlm.nih.gov/mesh?term=Surveys+and+Questionnaires"
data-ga-category="search_mesh"
data-ga-action="mesh_term_link"
data-ga-label="Surveys and Questionnaires">
Search in MeSH
</a></li><li><a class="add-to-search-link dropdown-block-link"
ref="linksrc=add_to_search_link"
role="button"
data-search-term="&quot;Surveys and Questionnaires&quot;[MeSH]"
data-ga-category="search"
data-ga-action="add_to_search"
data-ga-label="&quot;Surveys and Questionnaires&quot;[MeSH]"
href="#">
Add to Search
</a></li></ul></div></div></div></li></ul>
</div>
<div id="linkout" class="linkout">
<h2 class="title">
LinkOut - more resources
</h2>
<ul class="linkout-list"><li><h3 class="linkout-category">Full Text Sources</h3><ul class="linkout-category-links"><li><a
href="https://europepmc.org/abstract/MED/1878827"
target="_blank"
rel="noopener"
ref="linksrc=linkout_link&PrId=6082&uid=1878827&db=pubmed&itool=Abstract&log$=linkoutlink&nlmid=9711805"
data-ga-category="link_out"
data-ga-action="Full Text Sources"
data-ga-label="Europe PubMed Central"
>
Europe PubMed Central
</a></li><li><a
href="https://pmc.ncbi.nlm.nih.gov/articles/pmid/1878827/"
target="_blank"
rel="noopener"
ref="linksrc=linkout_link&PrId=3494&uid=1878827&db=pubmed&itool=Abstract&log$=linkoutlink&nlmid=9711805"
data-ga-category="link_out"
data-ga-action="Full Text Sources"
data-ga-label="PubMed Central"
>
PubMed Central
</a></li></ul></li></ul>
</div>
</main>
<div class="overlay" role="dialog" aria-label="Full Text Links Dialog">
<div id="full-text-links-dialog" class="dialog full-text-links-dialog">
<strong class="title">Full text links</strong>
<button class="close-overlay" tabindex="2">[x]</button>
<div class="full-text-links-list">
<a class="link-item
pmc
dialog-focus"
href="https://pmc.ncbi.nlm.nih.gov/articles/pmid/1878827/"
target="_blank"
rel="noopener"
ref="linksrc=fulltextorjournal_fulltext&amp;is_pmc=True&amp;PrId=3494&amp;itool=Abstract-def&amp;log$=linkouticon&amp;uid=1878827&amp;db=pubmed&amp;nlmid=9711805"
title="Free full text at PubMed Central"
tabindex="1"
data-ga-category="full_text"
data-ga-action="PMC"
data-ga-label="1878827"
><span class="text">
Free PMC article
</span></a>
</div>
</div>
</div>
<div class="overlay" role="dialog" aria-label="Citation Dialog">
<div class="dialog citation-dialog">
<button class="close-overlay" tabindex="1">[x]</button>
<div class="title">Cite</div>
<div class="citation-text-block">
<div class="citation-text"></div>
<div class="citation-actions">
<button
class="copy-button dialog-focus"
data-ga-category="save_share"
data-ga-action="cite"
data-ga-label="copy"
tabindex="2">
Copy
</button>
<form method="post">
<input type="hidden" name="csrfmiddlewaretoken" value="FMx3PBcqNyAVJPk8ztrDqvDO5mKFhh4SWzh8srFMn9npDgqYcM4FUD9sDqsRaSCc">
<button type="submit"
class="export-button"
data-ga-category="save_share"
data-ga-action="cite"
data-ga-label="download"
title="Download a file for external citation management software"
tabindex="3">
<span class="download-title">Download .nbib</span>
<span class="download-title-mobile">.nbib</span>
</button>
</form>
<div class="citation-style-selector-wrapper">
<label class="selector-label">Format:</label>
<select aria-label="Format" class="citation-style-selector" tabindex="4">
<option data-style-url-name="ama"
value="AMA"
>
AMA
</option>
<option data-style-url-name="apa"
value="APA"
>
APA
</option>
<option data-style-url-name="mla"
value="MLA"
>
MLA
</option>
<option data-style-url-name="nlm"
value="NLM"
selected="selected">
NLM
</option>
</select>
</div>
</div>
</div>
</div>
</div>
<div class="overlay" role="dialog" aria-label="More Actions Dialog">
<div id="more-actions-dialog" class="dialog more-actions-dialog">
<strong class="title">Send To</strong>
<ul class="more-actions-links">
<li><a id="clipboard-trigger" role="button" class="submit-button clipboard-trigger clipboard-trigger-target dialog-focus link-item " href="#">Clipboard</a></li>
<li><a class="email-trigger link-item" role="button" href="#">Email</a></li>
<li><a class="save-trigger link-item" role="button" href="#">Save</a></li>
<li><a class="link-item" role="button" href="https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F%23open-bibliography-panel">My Bibliography</a></li>
<li><a class="link-item" role="button" href="https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F%23open-collections-panel">Collections</a></li>
<li><a class="citation-manager-trigger link-item" role="button" href="#">Citation Manager</a></li>
</ul>
<button class="close-overlay">[x]</button>
</div>
</div>
</div>
<div id="ncbi-footer">
<div class="literature-footer" role="complementary" title="Links to NCBI Literature Resources">
<div class="usa-grid">
<p class="literature-footer-text">NCBI Literature Resources</p>
<p class="literature-footer-text">
<a class="literature-footer-link" data-ga-category="literature_resources" data-ga-action="mesh_link" href="https://www.ncbi.nlm.nih.gov/mesh/">MeSH</a>
<a class="literature-footer-link" data-ga-category="literature_resources" data-ga-action="pmc_link" href="https://www.ncbi.nlm.nih.gov/pmc/">PMC</a>
<a class="literature-footer-link" data-ga-category="literature_resources" data-ga-action="bookshelf_link" href="https://www.ncbi.nlm.nih.gov/books">Bookshelf</a>
<a class="literature-footer-link" data-ga-category="literature_resources" data-ga-action="disclaimer_link" href="/disclaimer/">Disclaimer</a>
</p>
<p class="literature-footer-text attribution-statement">The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.</p>
</div>
</div>
<!-- ========== BEGIN FOOTER ========== -->
<footer>
<section class="icon-section">
<div id="icon-section-header" class="icon-section_header">Follow NCBI</div>
<div class="grid-container container">
<div class="icon-section_container">
<a class="footer-icon" id="footer_twitter" href="https://twitter.com/ncbi" aria-label="Twitter">
<svg width="40" height="40" viewBox="0 0 40 37" fill="none" xmlns="http://www.w3.org/2000/svg">
<title>Twitter</title>
<g id="twitterx1008">
<path id="path1008"
d="M6.06736 7L16.8778 20.8991L6.00001 32.2H10.2L18.6 23.1L25.668 32.2H34L22.8 17.5L31.9 7H28.4L20.7 15.4L14.401 7H6.06898H6.06736ZM9.66753 8.73423H12.9327L29.7327 30.4658H26.5697L9.66753 8.73423Z"
fill="#5B616B"/>
</g>
</svg>
</a>
<a class="footer-icon" id="footer_facebook" href="https://www.facebook.com/ncbi.nlm" aria-label="Facebook"><svg
data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300">
<title>Facebook</title>
<path class="cls-11"
d="M210.5,115.12H171.74V97.82c0-8.14,5.39-10,9.19-10h27.14V52l-39.32-.12c-35.66,0-42.42,26.68-42.42,43.77v19.48H99.09v36.32h27.24v109h45.41v-109h35Z">
</path>
</svg></a>
<a class="footer-icon" id="footer_linkedin"
href="https://www.linkedin.com/company/ncbinlm"
aria-label="LinkedIn"><svg data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300">
<title>LinkedIn</title>
<path class="cls-11"
d="M101.64,243.37H57.79v-114h43.85Zm-22-131.54h-.26c-13.25,0-21.82-10.36-21.82-21.76,0-11.65,8.84-21.15,22.33-21.15S101.7,78.72,102,90.38C102,101.77,93.4,111.83,79.63,111.83Zm100.93,52.61A17.54,17.54,0,0,0,163,182v61.39H119.18s.51-105.23,0-114H163v13a54.33,54.33,0,0,1,34.54-12.66c26,0,44.39,18.8,44.39,55.29v58.35H198.1V182A17.54,17.54,0,0,0,180.56,164.44Z">
</path>
</svg></a>
<a class="footer-icon" id="footer_github" href="https://github.com/ncbi" aria-label="GitHub"><svg
data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 300 300">
<defs>
<style>
.cls-11,
.cls-12 {
fill: #737373;
}
.cls-11 {
fill-rule: evenodd;
}
</style>
</defs>
<title>GitHub</title>
<path class="cls-11"
d="M151.36,47.28a105.76,105.76,0,0,0-33.43,206.1c5.28,1,7.22-2.3,7.22-5.09,0-2.52-.09-10.85-.14-19.69-29.42,6.4-35.63-12.48-35.63-12.48-4.81-12.22-11.74-15.47-11.74-15.47-9.59-6.56.73-6.43.73-6.43,10.61.75,16.21,10.9,16.21,10.9,9.43,16.17,24.73,11.49,30.77,8.79,1-6.83,3.69-11.5,6.71-14.14C108.57,197.1,83.88,188,83.88,147.51a40.92,40.92,0,0,1,10.9-28.39c-1.1-2.66-4.72-13.42,1-28,0,0,8.88-2.84,29.09,10.84a100.26,100.26,0,0,1,53,0C198,88.3,206.9,91.14,206.9,91.14c5.76,14.56,2.14,25.32,1,28a40.87,40.87,0,0,1,10.89,28.39c0,40.62-24.74,49.56-48.29,52.18,3.79,3.28,7.17,9.71,7.17,19.58,0,14.15-.12,25.54-.12,29,0,2.82,1.9,6.11,7.26,5.07A105.76,105.76,0,0,0,151.36,47.28Z">
</path>
<path class="cls-12"
d="M85.66,199.12c-.23.52-1.06.68-1.81.32s-1.2-1.06-.95-1.59,1.06-.69,1.82-.33,1.21,1.07.94,1.6Zm-1.3-1">
</path>
<path class="cls-12"
d="M90,203.89c-.51.47-1.49.25-2.16-.49a1.61,1.61,0,0,1-.31-2.19c.52-.47,1.47-.25,2.17.49s.82,1.72.3,2.19Zm-1-1.08">
</path>
<path class="cls-12"
d="M94.12,210c-.65.46-1.71,0-2.37-.91s-.64-2.07,0-2.52,1.7,0,2.36.89.65,2.08,0,2.54Zm0,0"></path>
<path class="cls-12"
d="M99.83,215.87c-.58.64-1.82.47-2.72-.41s-1.18-2.06-.6-2.7,1.83-.46,2.74.41,1.2,2.07.58,2.7Zm0,0">
</path>
<path class="cls-12"
d="M107.71,219.29c-.26.82-1.45,1.2-2.64.85s-2-1.34-1.74-2.17,1.44-1.23,2.65-.85,2,1.32,1.73,2.17Zm0,0">
</path>
<path class="cls-12"
d="M116.36,219.92c0,.87-1,1.59-2.24,1.61s-2.29-.68-2.3-1.54,1-1.59,2.26-1.61,2.28.67,2.28,1.54Zm0,0">
</path>
<path class="cls-12"
d="M124.42,218.55c.15.85-.73,1.72-2,1.95s-2.37-.3-2.52-1.14.73-1.75,2-2,2.37.29,2.53,1.16Zm0,0"></path>
</svg></a>
<a class="footer-icon" id="footer_blog" href="https://ncbiinsights.ncbi.nlm.nih.gov/" aria-label="Blog">
<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><defs><style>.cls-1{fill:#737373;}</style></defs><path class="cls-1" d="M14,30a4,4,0,1,1-4-4,4,4,0,0,1,4,4Zm11,3A19,19,0,0,0,7.05,15a1,1,0,0,0-1,1v3a1,1,0,0,0,.93,1A14,14,0,0,1,20,33.07,1,1,0,0,0,21,34h3a1,1,0,0,0,1-1Zm9,0A28,28,0,0,0,7,6,1,1,0,0,0,6,7v3a1,1,0,0,0,1,1A23,23,0,0,1,29,33a1,1,0,0,0,1,1h3A1,1,0,0,0,34,33Z"/></svg>
</a>
</div>
</div>
</section>
<section class="container-fluid bg-primary">
<div class="container pt-5">
<div class="row mt-3">
<div class="col-lg-3 col-12">
<p><a class="text-white" href="https://www.nlm.nih.gov/socialmedia/index.html">Connect with NLM</a></p>
<ul class="list-inline social_media">
<li class="list-inline-item"><a href="https://twitter.com/NLM_NIH" aria-label="Twitter"
target="_blank" rel="noopener noreferrer">
<svg width="35" height="35" viewBox="0 0 38 35" fill="none" xmlns="http://www.w3.org/2000/svg">
<title>Twitter</title>
<g id="twitterx1009" clip-path="url(#clip0_65276_3946)">
<path id="Vector" d="M17.5006 34.6565C26.9761 34.6565 34.6575 26.9751 34.6575 17.4996C34.6575 8.02416 26.9761 0.342773 17.5006 0.342773C8.02514 0.342773 0.34375 8.02416 0.34375 17.4996C0.34375 26.9751 8.02514 34.6565 17.5006 34.6565Z" fill="#205493" stroke="white" stroke-width="1.2" stroke-miterlimit="10"></path>
<path id="path1009" d="M8.54811 8.5L16.2698 18.4279L8.50001 26.5H11.5L17.5 20L22.5486 26.5H28.5L20.5 16L27 8.5H24.5L19 14.5L14.5007 8.5H8.54927H8.54811ZM11.1197 9.73873H13.4519L25.4519 25.2613H23.1926L11.1197 9.73873Z" fill="white"></path>
</g>
<defs>
<clipPath id="clip0_65276_3946">
<rect width="38" height="38" fill="white"></rect>
</clipPath>
</defs>
</svg></a>
</li>
<li class="list-inline-item"><a href="https://www.facebook.com/nationallibraryofmedicine"
aria-label="Facebook" rel="noopener noreferrer" target="_blank">
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px"
y="0px" viewBox="0 0 249 249" style="enable-background:new 0 0 249 249;" xml:space="preserve">
<style type="text/css">
.st10 {
fill: #FFFFFF;
}
.st110 {
fill: none;
stroke: #FFFFFF;
stroke-width: 8;
stroke-miterlimit: 10;
}
</style>
<title>SM-Facebook</title>
<g>
<g>
<path class="st10" d="M159,99.1h-24V88.4c0-5,3.3-6.2,5.7-6.2h16.8V60l-24.4-0.1c-22.1,0-26.2,16.5-26.2,27.1v12.1H90v22.5h16.9
v67.5H135v-67.5h21.7L159,99.1z"></path>
</g>
</g>
<circle class="st110" cx="123.6" cy="123.2" r="108.2"></circle>
</svg>
</a></li>
<li class="list-inline-item"><a href="https://www.youtube.com/user/NLMNIH" aria-label="Youtube"
target="_blank" rel="noopener noreferrer"><svg version="1.1" xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 249 249"
style="enable-background:new 0 0 249 249;" xml:space="preserve">
<title>SM-Youtube</title>
<style type="text/css">
.st4 {
fill: none;
stroke: #FFFFFF;
stroke-width: 8;
stroke-miterlimit: 10;
}
.st5 {
fill: #FFFFFF;
}
</style>
<circle class="st4" cx="124.2" cy="123.4" r="108.2"></circle>
<g transform="translate(0,-952.36218)">
<path class="st5"
d="M88.4,1037.4c-10.4,0-18.7,8.3-18.7,18.7v40.1c0,10.4,8.3,18.7,18.7,18.7h72.1c10.4,0,18.7-8.3,18.7-18.7
v-40.1c0-10.4-8.3-18.7-18.7-18.7H88.4z M115.2,1058.8l29.4,17.4l-29.4,17.4V1058.8z"></path>
</g>
</svg></a></li>
</ul>
</div>
<div class="col-lg-3 col-12">
<p class="address_footer text-white">National Library of Medicine<br>
<a href="https://www.google.com/maps/place/8600+Rockville+Pike,+Bethesda,+MD+20894/@38.9959508,-77.101021,17z/data=!3m1!4b1!4m5!3m4!1s0x89b7c95e25765ddb:0x19156f88b27635b8!8m2!3d38.9959508!4d-77.0988323"
class="text-white" target="_blank" rel="noopener noreferrer">8600 Rockville Pike<br>
Bethesda, MD 20894</a></p>
</div>
<div class="col-lg-3 col-12 centered-lg">
<p><a href="https://www.nlm.nih.gov/web_policies.html" class="text-white">Web Policies</a><br>
<a href="https://www.nih.gov/institutes-nih/nih-office-director/office-communications-public-liaison/freedom-information-act-office"
class="text-white">FOIA</a><br>
<a href="https://www.hhs.gov/vulnerability-disclosure-policy/index.html" class="text-white" id="vdp">HHS Vulnerability Disclosure</a></p>
</div>
<div class="col-lg-3 col-12 centered-lg">
<p><a class="supportLink text-white" href="https://support.nlm.nih.gov/">Help</a><br>
<a href="https://www.nlm.nih.gov/accessibility.html" class="text-white">Accessibility</a><br>
<a href="https://www.nlm.nih.gov/careers/careers.html" class="text-white">Careers</a></p>
</div>
</div>
<div class="row">
<div class="col-lg-12 centered-lg">
<nav class="bottom-links">
<ul class="mt-3">
<li>
<a class="text-white" href="//www.nlm.nih.gov/">NLM</a>
</li>
<li>
<a class="text-white"
href="https://www.nih.gov/">NIH</a>
</li>
<li>
<a class="text-white" href="https://www.hhs.gov/">HHS</a>
</li>
<li>
<a
class="text-white" href="https://www.usa.gov/">USA.gov</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
</section>
</footer>
<!-- ========== END FOOTER ========== -->
<!-- javascript to inject NWDS meta tags. Note: value of nwds_version is updated by "npm version" command -->
<script type="text/javascript">
var nwds_version = "1.2.3";
var meta_nwds_ver = document.createElement('meta');
meta_nwds_ver.name = 'ncbi_nwds_ver';
meta_nwds_ver.content = nwds_version;
document.getElementsByTagName('head')[0].appendChild(meta_nwds_ver);
var meta_nwds = document.createElement('meta');
meta_nwds.name = 'ncbi_nwds';
meta_nwds.content = 'yes';
document.getElementsByTagName('head')[0].appendChild(meta_nwds);
var alertsUrl = "/core/alerts/alerts.js";
if (typeof ncbiBaseUrl !== 'undefined') {
alertsUrl = ncbiBaseUrl + alertsUrl;
}
</script>
</div>
<!-- jQuery with plugins -->
<script src="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/js/output.293fbf76aa18.js"></script>
<!-- Project base scripts -->
<script src="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/js/output.550e9c8906a2.js"></script>
<script>
ncbi.awesome.basePage.init({
userInfo: {
isLoggedIn: false,
username: "",
loginUrl: "https://account.ncbi.nlm.nih.gov/?back_url=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F1878827%2F",
logoutUrl: "https://www.ncbi.nlm.nih.gov/account/signout/?back_url=https%3A//pubmed.ncbi.nlm.nih.gov/1878827/"
},
baseUrl: 'https://www.ncbi.nlm.nih.gov',
noSessionCookieName: "pm-ns",
searchIdCookieName: "pm-sid",
adjNavSearchIdCookieName: "pm-adjnav-sid",
searchFormSubmittedCookieName: "pm-sfs",
isOnSearchPageCookieName: "pm-iosp",
backToSearchCookieName: "pm-btsl",
clinicalSeeAllCookieName: "pm-csa",
jsCookieDomain: "pubmed.ncbi.nlm.nih.gov",
userShareRequestFailed: "",
noSharedSettings: "myncbi_no_shared_settings",
noSharedAccount: "myncbi_no_shared_account"
});
</script>
<script type="module">
import dismissableNCBIAlert from "https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/core/dismissable-ncbi-alert.js";
jQuery.getScript("https://www.ncbi.nlm.nih.gov/core/alerts/alerts.js", function () {
galert(['body > *:last-child']);
dismissableNCBIAlert();
}).fail(function() {
});
</script>
<script defer type="text/javascript" src="https://cdn.ncbi.nlm.nih.gov/core/pinger/pinger.js"> </script>
<script src="https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/CACHE/js/output.e3950ac8c6da.js"></script>
<script>
ncbi.awesome.articlePage.init({
baseSuggestionsUrl: "/suggestions/",
mathJaxUrl: "https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/mathjax/unpacked/MathJax.js?config=MML_CHTML",
clipboardAPIRoot: "/ajax/clipboard/",
clipboardNextPageUrl: "/clipboard-next-page/",
searchIdCookieName: "pm-sid",
searchFormSubmittedCookieName: "pm-sfs",
backToSearchCookieName: "pm-btsl",
jsCookieDomain: "pubmed.ncbi.nlm.nih.gov",
longTermPrefix: "longquery",
adjNavURLPath: "/1878827/adj-nav/",
adjNavSearchIdCookieName: "pm-adjnav-sid",
articlePageUrl: "/1878827/",
markJSUrl: "https://cdn.ncbi.nlm.nih.gov/pubmed/277eb475-38df-4990-a0ee-0080b04e86fc/mark.js/dist/jquery.mark.js",
termHighlightColor: "",
highlightedTokens: "",
citeFormatPreferenceCookieName: "pm-cf"
});
</script>
</body>
</html>