Patient Care/Clinical Decisionmaking

Factors identified that predict the need for ICU admission of ER patients with acute chest pain

When patients arrive at the emergency department (ED) with acute chest pain, it is often difficult to evaluate whether they are suffering from a heart attack or are at high risk for having one. This complicates decisions about their need for hospitalization and admission to the intensive care unit (ICU), an intermediate care unit, or elsewhere in the hospital. A recent report by Lee Goldman, M.D., of the University of California, San Francisco, and his colleagues involved in the Multicenter Chest Pain Study defines clinical characteristics that predict patient risk for heart attack and may make patient triage easier.

The study shows that patients who arrive at the ED with acute chest pain and have electrocardiographic (ECG) abnormalities are most at risk of major complications such as cardiac arrest or cardiogenic shock within the first 24 hours. Systolic blood pressure below 110 mm Hg, and especially below 100 mm Hg, also predicts complications. These high-risk ED patients should probably be admitted to the ICU. Also, patients at moderate risk based on ECG criteria or on the combination of unstable angina and abnormal pump function (indicated by relative low blood pressure or substantial heart failure) also are candidates for ICU admission, explains Dr. Goldman.

As the researchers point out, any patient in whom a major event develops (for example, cardiac arrest, ventricular fibrillation, cardiogenic shock, or recurrent chest pain requiring bypass surgery or angioplasty) is at high risk for a subsequent major event. Patients without initial complications who are at too high a risk to be sent home but have a low probability of having a heart attack or other major event may be monitored in an intermediate care unit or in an area adjacent to or in the ED, according to the researchers. They studied 10,682 patients with acute chest pain at seven hospitals between 1984 and 1986 to identify potential clinical predictors of major complications. They then validated these predictors in a separate set of 4,676 patients at one hospital between 1990 and 1994.

These findings may be useful prospectively or retrospectively to managed care organizations and hospitals that are seeking ways to improve the quality and efficiency of their care for patients with acute chest pain. The characteristics described in this study may be used to identify both over- and underutilization of the ICU.

This study was supported in part by the Agency for Health Care Policy and Research (HS06452) through a grant to Thomas H. Lee, M.D., of Harvard Medical School. Details are in "Prediction of the need for intensive care in patients who come to emergency departments with acute chest pain," by Lee Goldman, M.D., E. Francis Cook, Sc.D., Paula A. Johnson, M.D., Donald A. Brand, Ph.D., Gregory W. Rouan, M.D., and Dr. Lee, in the June 6, 1996 issue of The New England Journal of Medicine 334(23), pp. 1498-1504.

Much of the variation across hospitals in short-term survival of elderly heart attack patients remains unexplained

Many elderly persons suffering heart attacks die within a month, and it is unclear why some patients survive and others do not. About 70 percent of the variation in death following acute myocardial infarction (AMI) remains unexplained, even after patient severity of illness at admission is accounted for, according to a study by the AMI Patient Outcomes Research Team (PORT). The researchers could not determine whether this variation was due to unmeasured patient characteristics, to chance, or to quality of care. For this reason, they caution against using short-term survival after AMI as a means of comparing quality of care across hospitals.

The AMI PORT researchers, led by Barbara J. McNeil, M.D., Ph.D., of Harvard Medical School, analyzed medical chart and administrative data on 14,581 AMI Medicare patients in acute care hospitals in four States in 1993. They developed a model to determine the predictive value of certain factors on 30-day mortality of elderly patients following AMI. The 30-day mortality rate, unadjusted for disease severity or coexisting medical conditions, was 21 percent. It ranged from 18 percent in Connecticut to 23 percent in Alabama, where heart attack patients received fewer drug therapies and more revascularization procedures than similar patients in other States.

The four largest contributors to variability in mortality rates were mean arterial pressure, age, respiratory rate, and serum urea nitrogen level. Differences in patient status at admission explained only 27 percent of the variability in 30-day mortality rates, and incorporation of drug therapies and revascularization procedures explained 6 percent more (up to 33 percent) of the variation. The researchers suggest that the medical community expand efforts to develop a series of quality indicators based on process measures for AMI and other diagnoses.

This research was supported by the Agency for Health Care Policy and Research (HS06341 and HS08071). See "Using admission characteristics to predict short-term mortality from myocardial infarction in elderly patients," by Sharon-Lise T. Normand, Ph.D., Mark E. Glickman, Ph.D., R.G.V.R.K. Sharma, M.D., and Dr. McNeil, in the May 1, 1996 Journal of the American Medical Association 275(17), pp. 1322-1328.

Stroke PORT publishes its latest findings

Each year in the United States, about 3 million people are diagnosed with stroke, 450,000 suffer a new nonfatal stroke, and about 150,000 die from stroke. In 1993, the cost of caring for stroke victims in the United States was an estimated $30 billion. More widespread and effective stroke prevention could reduce this costly burden.

Stroke prevention is the goal of the Secondary and Tertiary Prevention of Stroke Patient Outcomes Research Team (PORT), supported by the Agency for Health Care Policy and Research (contract 282-91-0028). Led by David Matchar, M.D., of Duke University Medical Center, the Stroke PORT recently published three studies discussed here.

McCrory, D.C., and Matchar, D.B. "Stroke prevention: The emerging strategies" (1996, March). Hospital Practice, pp. 123-134.

The results of an extensive literature review by PORT researchers show that the anticoagulant warfarin prevents more than 23 strokes or deaths for every nonfatal episode of major bleeding it causes in patients with atrial fibrillation; yet physicians still are reluctant to use warfarin for stroke prevention because of concerns about bleeding complications and age-related sensitivity to the drug, especially in the elderly. Since relatively small increases in warfarin can cause large increases in the time it takes the blood to coagulate (prothrombin time), optimal therapy with warfarin requires regular blood monitoring of the drug's anticoagulant effect. The authors suggest that many of the impediments to the use of prophylactic warfarin might be overcome by establishing specialized anticoagulation clinics which would provide the careful monitoring needed to avoid bleeding complications. These clinics could increase the utilization of warfarin where anticoagulation prophylaxis is indicated, including its use for patients with nonvalvular atrial fibrillation (NVAF)—rapid, irregular contractions of the atrium that can lead to stroke.

Leibson, C.L., Hu, T., Brown, R.D., and others (1996, March). "Utilization of acute care services in the year before and after first stroke: A population-based study." Neurology 46, pp. 861-869.

In this comparative study, Stroke PORT researchers found that total acute care charges in the year after stroke were 3.4 times those for the previous year. Although more than half of these charges were incurred in the first 30 days immediately after the stroke, mean monthly charges for acute care remained significantly above prestroke levels for up to 5 months after the event. Poststroke charges per person-day of followup were significantly higher for individuals who were:(1) hospitalized for the stroke, (2) had subarachnoid hemorrhage, (3) had the stroke after hospital admission for another reason, or (4) died within 7 days. Significantly lower poststroke charges were incurred by persons with mild cerebral infarctions and persons whose stroke occurred in a nursing home. These findings are based on data from the Rochester Stroke Registry, which catalogs stroke in residents of Rochester, MN, and on the Olmsted County Utilization Dataset, which tracks resource utilization in the Rochester population. The study followed 289 individuals with confirmed first stroke during the period 1987 to 1989.

Holloway, R.G., Witter, Jr., D.M., Lawton, K.B., and others (1996, March). "Inpatient costs of specific cerebrovascular events at five academic medical centers." Neurology 46, pp. 854-860.

This study by PORT researchers showed that the cost of hospital services differs depending on the type of cerebrovascular disease. The most expensive subgroup was subarachnoid hemorrhage (SAH), with a mean discharge cost of $39,994. The intracerebral hemorrhage (ICH) group had a mean discharge cost of $21,535, whereas the ischemic cerebral infarction (ICI) and the transient ischemic attack (TIA) groups cost approximately $9,882 and $4,653, respectively. Mean cost per inpatient day also varies as follows: $2,215 for SAH, $1,396 for ICH, $1,036 for ICI, and $1,117 for TIA. Length of hospital stay strongly influences inpatient costs; other contributors include stroke severity, social factors, and clinical practice variations. After controlling for type of stroke, PORT researchers found that basic demographic variables (e.g., age, race, and sex) and patient insurance status contribute little to the total cost of inpatient stroke care. These findings are based on analysis of administrative data on hospital discharges from five academic medical centers during 1992.

Surgery for spinal stenosis has increased

Spinal stenosis, which can cause symptoms ranging from temporary numbness of an extremity to muscle weakness, occurs most commonly in older adults and is caused by compression of the spinal nerve root that attaches the nerve to the spinal cord. Surgery for spinal stenosis increased eight-fold from 1979 to 1992 and varied in use nearly five-fold across the United States, according to a recent study by the Back Pain Patient Outcomes Research Team (PORT). The investigators also found a substantial complication rate from this elective surgery. Widespread variation in the use of this procedure, combined with its high complication rate, suggest the need for more information on the relative efficacy of surgical and nonsurgical treatments for spinal stenosis, concludes Richard A. Deyo, M.D., M.P.H., leader of the Back Pain PORT project.

The researchers, who were supported in part by the Agency for Health Care Policy and Research (HS06344 and HS08194), studied all Medicare beneficiaries who received a lumbar spine operation for spinal stenosis in 1985 or 1989 and followed them through 1991. In 1985 the surgery rates ranged from 17 (New York) to 81 (Idaho) operations per 100,000 Medicare beneficiaries and in 1989, from 30 (Rhode Island) to 132 (Utah). Deaths in the hospital or shortly after discharge were 0.8 percent for patients younger than age 75 but about 1.1 percent for those aged 75 to 79 and 2.3 percent for those 80 years of age and older. Complications occurred in 2.4 percent of individuals who did not have other coexisting medical conditions and in 4.1 percent of those who had three or more other conditions. Complications were more likely for men and for individuals receiving spinal fusions.

As the U.S. population ages, the prevalence of spinal stenosis and rates of surgical intervention can be expected to increase. The researchers recommend that physicians inform patients of associated risks, which are considerably higher than those associated with disk surgery, an operation usually performed on younger individuals.

Details are in "An assessment of surgery for spinal stenosis: Time trends, geographic variations, complications, and reoperations," by Marcia A. Ciol, Ph.D., Dr. Deyo, Eric Howell, M.S., and Suzanne Kreif, B.S., B.S.I.M., in the March 1996 Journal of the American Geriatrics Society 44, pp. 285-290.

Age-related differences in patients undergoing surgery are narrowing for some cancers

Age-related differences in the treatment of cancer patients may be diminishing, perhaps due to the greater robustness of today's elderly, according to a new study supported in part by the Agency for Health Care Policy and Research (HS06879). It shows that, although older persons are less apt to receive surgical treatment for cancer than younger persons, the age gap narrowed for certain cancers from 1973 through 1991.

During that time, the likelihood of receiving surgery for cancers of the uterus, colon, rectum, ovary, and breast increased more rapidly among patients aged 65 years and older than among younger patients. Even in the oldest age groups, a majority of patients now receive surgery for these common cancers. However, physicians still are less likely to use surgery to treat older patients who have cancer of the lung, stomach, or pancreas. Surgery for these cancers is more invasive and risky, there are only marginal potential benefits, and survival rates are poor, explains Jonathan M. Samet, M.D., of the Johns Hopkins University School of Hygiene and Public Health.

Dr. Samet and his colleagues used the SEER Program of the National Cancer Institute to examine population-based data for nine geographic areas in the United States on treatment of persons with cancer of the breast, colon, rectum, lung, ovary, uterus, pancreas, and stomach between 1973 and 1991. Results showed that after age 64, the percentage of patients treated surgically decreased with increasing age for every cancer site studied. However, the gap narrowed between older and younger patients for certain cancers.

For example, by 1986-1991, the proportion of women younger than age 55 receiving surgery for uterine cancer had increased only slightly (from 89 percent to 94 percent), but it had risen markedly from 68 percent to 88 percent for those 75-84 years of age and from 34 percent to 56 percent for women 85 years and older. A similar but less pronounced catch-up effect was observed for cancers of the colon, rectum, and breast. For cancers of the lung, stomach, and pancreas, the gap did not narrow between older and younger patients receiving surgery.

Details are in "Temporal and regional variability in the surgical treatment of cancer among older people," by Diana C. Farrow, Ph.D., William C. Hunt, M.S., and Dr. Samet, in the May 1996 Journal of the American Geriatrics Society 44(5), pp. 559-564.

Return to Contents
Proceed to Next Section