Comparing patient characteristics, type of intervention, control, and outcome (PICO) queries with unguided searching: a randomized controlled crossover trial.

BACKGROUND Translating a question into a query using patient characteristics, type of intervention, control, and outcome (PICO) should help answer therapeutic questions in PubMed searches. The authors performed a randomized crossover trial to determine whether the PICO format was useful for quick searches of PubMed. METHODS Twenty-two residents and specialists working at the Radboud University Nijmegen Medical Centre were trained in formulating PICO queries and then presented with a randomized set of questions derived from Cochrane reviews. They were asked to use the best query possible in a five-minute search, using standard and PICO queries. Recall and precision were calculated for both standard and PICO queries. RESULTS Twenty-two physicians created 434 queries using both techniques. Average precision was 4.02% for standard queries and 3.44% for PICO queries (difference nonsignificant, t(21) = -0.56, P = 0.58). Average recall was 12.27% for standard queries and 13.62% for PICO queries (difference nonsignificant, t(21) = -0.76, P = 0.46). CONCLUSIONS PICO queries do not result in better recall or precision in time-limited searches. Standard queries containing enough detail are sufficient for quick searches.