Table 1.

Search results with and without duplicates.

Database	Duplicates included, n	Duplicates removed, n
ACM Digital Library	292	289
Applied Science &Technology Source	37	23
CINAHL	360	291
ClinicalTrials.gov	47	47
Cochrane Library	224	105
Ei Compendex	120	106
EMBASE	736	640
Google Scholar	67	37
IEEE Xplore	453	344
Ovid MEDLINE	1277	1276
PsycINFO	250	134
PubMed	507	507
Scopus	207	106
Web of Science	175	50
Total	4752	3955