Table 2.

Recruitment studies – summary of predictors

				Parent									Child		Family		Neighbourhood
Author	Predicting	Setting	Medical or non- medical intervention	Ethnicity	Education	Parent Age	Income	SES	Parental depression	Single parenthood	Marital status	Employment	Child gender	Child age	Number of family members	Number of children	N'hood high school drop out	Density of n'hood networks
Baker et al., 2011 [23]	Recruitment	Community	Non- medical	✔				✔	X	X
Byrnes et al., 2012 [25]	Recruitment	Health	Non- medical	✔	✔	✔							X				✔
Constantine et al., 1993 [26]	Recruitment	Mixed	Non- medical	✔
Cunningham et al., 2000 [28]	Recruitment	Community	Non- medical		✔		X		X	✔			✔	X
Damashek et al., 2011 [29]	Recruitment	Community	Non- medical	X	X	X	X		✔
Daniels et al., 2012 [30]	Recruitment	Community	Non- medical	X	✔	✔					✔
Eisner M and Meidert U, 2011 [31]	Recruitment	Community	Non- medical	✔			✔	✔		X								✔
Heinrichs et al., 2005 [35]	Recruitment	Community	Non- medical			X		✔		✔					X
Ireys et al., 2001 [36]	Recruitment	Mixed	Medical	✔					✔				X
Mihrshahi et al., 2002 [39]	Recruitment	Community	Medical	X	✔	X						X
Multi-centre Otitis Media Study Group, 2001 [38]	Recruitment	Health	Medical	X				X					X	X		X
Van den Akkeret al., 2003 [44]	Recruitment	Health	Medical										X	X
Vermaire et al., 2011 [49]	Recruitment	Health	Non- medical	✔				✔		X	X		X
Winslow et al., 2009 [47]	Recruitment	Mixed	Non- medical	X	X		✔
Zebracki et al., 2003 [48]	Recruitment	Health	Medical	X	X	✔	X				X	X			X
			Total	12	7	6	5	5	4	5	3	2	6	3	2	1	1	1
			Significant	6	4	3	2	4	2	2	1	0	1	0	0	0	1	1
		Non- significant		6	3	3	3	1	2	3	2	2	5	3	2	1	0	0

Key: x = not significant, ✔ = significant, SES socioeconomic status