The contribution of databases to the results of systematic reviews: a cross-sectional study

Table 2 Databases where trials were found that were not found in Medline^a

	Acute Respiratory Infections (n = 57 meta-analyses)		Infectious Diseases (n = 38 meta-analyses)		Developmental, Psychosocial and Learning Problems (n = 34 meta-analyses)
Database	Total Trials Found (of 398)^b	Number found that were not in MedLine (of 65)	Total Trials Found (of 238)^b	Number found that were not in MedLine (of 32)	Total Trials Found (of 144)^b	Number found that were not in MedLine or PsycINFO (of 23)
Medline	333 (84 %)	-	206 (87 %)	-	-	-
BIOSIS	258	13	164	7	72	1
CAB Direct	1	0	4	0	0	0
CINAHL	75	0	32	1	43	0
EMBASE	310	20	178	6	84	2
ERIC	1	1	0	0	32	4
HAPI	0	0	0	0	0	0
IPA	104	3	40	1	13	0
LILACS	0	0	5	0	2	0
PsycINFO	8	3	2	0	121 (84 %)^c	-

^aPercentages do not match those in Table 1; the percentages here are an average across all trials (by review group)
^bNumber of trials not found in any database was 26 for ARI, 18 for ID, and 12 for DPLP. Number of systematic reviews with ≥1 trial not found in any database was 10 for ARI, 9 for ID, and 8 for DPLP
^cTotal trials found in Medline and/or PsycINFO

ISSN: 1471-2288