The search hedges shall help to search for randomized controlled trials (RCTs) in EMBASE based on the publication of Wong *. Depending on the desired sensitivity (number of hits) and specificity, it can be chosen between one of four different search hedges:
 
CharacteristicsSearch Hedge
Best sensitivityti,ab(random*) or ti,ab,su("clinical trial*") or emb.exact.explode("health care quality")
Small drop in sensitivity with a substantive gain in specificityti,ab(random*) or ti,ab,su("clinical trial*") or emb.exact.explode("treatment outcome")
Best specificityti,ab,su("double-blind*") or ti,ab,su(placebo*) or ti,ab(blind*)
Best optimization of sensitivity and specificityti,ab(random*) or ti,ab,su(placebo) or ti,ab("double-blind*")
* Wong SS, Wilczynski NL, Haynes RB. Developing optimal search strategies for detecting clinically sound treatment studies in EMBASE. Journal of the Medical Library Association 2006;94(1):41-7. [Ovid]