Table 2.

Overview of systematic review search filter's performance in PubMed and Embase

	PubMed
	Relevant records in retrospective searches (= gold standard, a+b): 77	Irrelevant records in retrospective searches (c+d): 23,201
Records retrieved with search filter (a+c): 713	True positives (a): 69	False positives (c): 644
Records not retrieved with search filter: 22,565	False negatives (b): 8	True negatives (d): 22,557
	Embase
	Relevant records in retrospective searches (= gold standard, a+b): 70	Irrelevant records in retrospective searches (c+d): 30,670
Records retrieved with search filter (a+c): 1,192	True positives (a): 64	False positives (c): 1,128
Records not retrieved with search filter: 29,548	False negatives (b): 6	True negatives (d): 29,542