Varied Search Protocols Lead to Clinically Relevant Results

Marcy L. Brown


A review of:
Patel, Manesh R., Connie M. Schardt, Linda L. Sanders, and Sheri A. Keitz. “Randomized Trial for Answers to Clinical Questions: Evaluating a Pre-Appraised Versus a MEDLINE Search Protocol.” Journal of the Medical Library Association 94.4 (2006): 382-6.

Objective – To determine the success rate of electronic resources for answering clinical questions by comparing speed, validity, and applicability of two different protocols for searching the medical literature.

Design – Randomized trial with results judged by blinded panel.

Setting – Duke University Medical Center in Durham, North Carolina, United States of America.

Subjects – Thirty-two 2nd and 3rd year internal medicine residents on an eight-week general medicine rotation at the Duke University Medical Center.

Methods – Two search protocols were developed:

Protocol A: Participants searched MEDLINE first, and then searched pre-appraised resources if needed.

Protocol B: Participants searched pre-appraised resources first, which included UpToDate, ACP Journal Club, Cochrane Database of Systematic Reviews, and DARE. The residents then searched MEDLINE if an answer could not be found in the initial group of pre-appraised resources.

Residents were randomised by computer-assisted block order into four blocks of eight residents each. Two blocks were assigned to Protocol A, and two to Protocol B. Each day, residents developed at least one clinical question related to caring for patients. The questions were transcribed onto pocket-sized cards, with the answer sought later using the assigned protocol. If answers weren’t found using either protocol, searches were permitted in other available resources.

When an article that answered a question was found, the resident recorded basic information about the question and the answer as well as the time required to find the answer (less than five minutes; between five and ten minutes; or more than ten minutes). Residents were to select answers that were “methodologically sound and clinically important” (384). Ten faculty members formally trained in evidence-based medicine (EBM) reviewed a subset of therapy-related questions and answers. The reviewers, who were blinded to the search protocols, judged the applicability and internal validity of the answers.

Results – In total, 120 questions were searched using protocol A and 133 using protocol B; 104 answers were found by the protocol A group and 117 by the protocol B group. In protocol A, 97 answers were found in MEDLINE (80.8%) and six answers were found in pre-appraised resources (5.0%). In protocol B, 85 answers were found in pre-appraised resources (64.6%) and 31 were found in MEDLINE (23.3%). UpToDate was the major resource for answers in protocol B.

A statistically greater number of answers were found in less than five minutes in protocol B (p<0.00004). However, a greater number of questions went unanswered in protocol B (23%).

The faculty reviewers determined that 75.8% of the answers in protocol A were applicable; 71.7% were judged applicable in protocol B. Eighty percent in protocol A were internally valid, while 81.8% were valid in protocol B.

Conclusion – The study demonstrates that to find answers to as many clinical questions as possible, “residents and clinicians need access to both pre-appraised resources and MEDLINE” (385). Pre-appraised resources were faster to search, but their coverage was not as comprehensive. MEDLINE is comprehensive, but takes more time to search effectively and requires that the clinician or student have some knowledge of critical appraisal in order to judge relevance and applicability of found articles. Protocol B may be difficult to implement in many institutions because of the high cost of pre-appraised resources.

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