Health technology assessment in social care: a case study of randomized controlled trial retrieval.

Objectives: The aim of this study was to evaluate the success of search strategies in retrieving key documents for a technology assessment report (TAR) on a social care topic.

Methods: This study measured the differential yield of relevant studies from various information sources and evaluated strategies in different databases, with particular reference to capturing randomized controlled trials (RCTs) as a study design.

Results: A combination of four major databases would have found all thirty-two key references. One database alone would have found 78 percent, with another two each locating 59 percent. Sixteen percent of the trials were unique references. In non-health care databases, more sensitive search strategies would have resulted in a higher yield of relevant studies, in part due to inconsistent indexing and in part to attempts to restrict searches to RCTs. Although additional terms could be used to increase the sensitivity of the original strategies, this raises the question of trading off time against exhaustiveness, given the greater number of irrelevant references likely to be retrieved.

Conclusions: A successful search for evidence on this social care topic would be possible using a combination of MEDLINE, EMBASE, the Cochrane Library and PsyclNFO, supplemented by only limited use of supplementary databases. In areas such as social care where evidence-based research is not yet well established, attempts to replicate searches based on study design do not seem to be advisable, although this may be an area for future research.