Table 3.

Overview of the original intervention study search filter's performance in PubMed and Embase in the derivation reference gold standard

	PubMed
	Relevant records in a retrospective search (= gold standard, a+b): 116	Irrelevant records in a retrospective search (c+d): 9,717
Records retrieved with search filter (a+c): 3,218	True positives (a): 98	False positives (c): 3,120
Records not retrieved with search filter: 6,615	False negatives (b): 18	True negatives (d): 6,597
	Embase
	Relevant records in a retrospective search (= gold standard, a+b): 103	Irrelevant records in a retrospective search (c+d): 14,484
Records retrieved with search filter (a+c): 5,437	True positives (a): 85	False positives (c): 5,352
Records not retrieved with search filter: 9,150	False negatives (b): 18	True negatives (d): 9,132