Comparison of search strategies on CD Plus/MEDLINE

Abstract

OBJECTIVE: To compare two strategies for searching MEDLINE using the CD Plus/MEDLINE program on compact disc. DESIGN: Comparison study. INTERVENTIONS: 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. OUTCOME MEASURES: Number of articles retrieved, number of relevant articles, precision and recall of each search strategy and overlap between strategies. MAIN RESULTS: 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). CONCLUSIONS: 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.