Objectives: For general practitioners (GPs), an important obstacle to practising evidence-based medicine is lack of time. An evidence-based answering service was developed that took over searching and appraisal of medical evidence from the GPs. GPs sent in questions, and the informationist formulated the answers. Our objectives were to find out if such an evidence-based answering service was feasible, including assessing the effect of the answers on GPs and their patients, as reported by the GPs.

Methods: After attending a workshop on building well-formulated questions from daily practice, the GPs sent in questions to the informationist. The literature was searched, the relevant information was appraised, and the answers to the questions were formulated. With a questionnaire, the effect of the answers on the GP and the patient was assessed, as well as the perceived barriers to implementing the answers.

Results: From 26 GPs, 61 questions were received. For 12% of questions, information was found with the highest evidence level, while for 36%, no information was found. However, for 89% of the questions for which no information could be found, the answer 'no information found' did have an effect on the GP concerned. In total, 81% of all the answers had an effect on the GP, and, according to the GP, 52% had an effect on the patient. Few barriers to implementing the evidence were perceived. Most of the answers were found in Pubmed/Medline, the Cochrane Library and Embase.

Conclusions: This study indicates that an evidence-based answering service can have an impact on GPs and their patients. Librarians can provide an evidence-based answering service for GPs and their patients. The evidence-based answering service for GPs in this study had an impact on 81% of the GPs and on 52% of their patients. Although for one-third of the questions no evidence-based answer was found, this message in itself had an impact on 89% of the GPs. An informationist as mediator between medical information and doctors can save doctors' time.