Table 2.

Quality assessment of studies included

Study	Criteriaa									Total /9	Quality
	1	2	3	4	5	6	7	8	9
Aldridge H et al. 2017 [27]	+	+	+	+	+	–	+	+	+	8	Moderate
Aminzadeh F et al. 2009 [28]	+	+	+	+	+	–	+	+	+	8	Moderate
Aminzadeh F et al. 2010 [29]	+	+	+	+	+	–	–	+	+	7	Moderate
Atta-Konadu E et al. 2011 [30]	+	+	+	+	+	–	–	+	+	7	Moderate
Barrett C and Crameri P 2015 [31]	+	+	+	–	+−	–	+	+	+	7	Moderate
Beattie et al. 2004 [32]	+	+	+	+	+	–	+	+	+	8	Moderate
Borley G and Hardy S 2017 [33]	+	+	+	+	+	–	+	+	+	8	Moderate
Bronner K et al. 2016 [34]	+	+	+	+	+	–	–	+	+	7	Moderate
Brorsson et al. 2011 [35]	+	+	+	+	+	–	+	+	+	8	Moderate
Chaplin R et al. 2016 [36]	+	+	+	+	+	–	+	+	+	8	Moderate
Clare L et al. 2008 [37]	+	+	+	+	+	–	+	+	+	8	Moderate
Clemerson G et al. 2014 [38]	+	+	+	+	+	–	+	+	+	8	Moderate
Dalby P et al. 2012 [39]	+	+	+	+	+	+	+	+	+	9	High
Derksen E et al. 2006 [40]	+	+	+	+	+	–	+	+	+	8	Moderate
De Witt 2009 [41]	+	+	+	+	+	–	+	+	+	8	Moderate
De Witt 2010 [42]	+	+	+	+	+	–	+	+	+	8	Moderate
Digby 2011 [43]	+	+	+	+	+	+	+	–	+	8	Moderate
Digby 2012 [44]	+	+	+	+	+	+	+	+	+	9	High
Duggan et al. 2008 [45]	+	+	+	+	+	–	+	–	+	7	Moderate
Fleming R et al. 2015 [46]	+	+	+	+	+	+	+	+	+	9	High
Frazer SM et al. 2011 [47]	+	+	+	+	+	–	+	+	+	8	Moderate
Genoe MR et al. 2010 [48]	+	+	+	+	+	–	+	+	+	8	Moderate
Genoe MR et al. 2012 [49]	+	+	+	+	+	–	+	+	+	8	Moderate
Genoe MR and Dupuis SL 2014 [50]	+	+	+	+	+	+	+	+	+	9	High
Gill L et al. 2011 [51]	+	+	+	+	+	–	+	+	+	8	Moderate
Gilmour JA and Huntington AD 2005 [52]	+	+	+	+	+	–	+	+	+	8	Moderate
Goodman C et al. 2013 [53]	+	+	+	+	+	–	+	+	+	8	Moderate
Hain D et al. 2014 [54]	+	+	+	–	+	–	+	+	+	7	Moderate
Harman G and Clare L 2006 [55]	+	+	+	+	+	+	+	+	+	9	High
Harris PB 2011 [56]	+	+	+	+	+	–	+	+	+	8	Moderate
Hedman R et al. 2013 [57]	+	+	+	+	+	–	+	+	+	8	Moderate
Hedman R et al. 2016 [58]	+	+	+	+	+	+	+	+	+	9	High
Heggestad A et al. 2013 [59]	+	+	+	+	+	+	+	+	+	9	High
Hellström I et al. 2015 [60]	+	+	+	–	+	–	+	+	+	7	Moderate
Herron RV and Rosenberg MW 2017 [61]	+	+	+	–	+	–	+	+	+	7	Moderate
Hillmann A et al. 2018 [62]	+	+	+	–	+	–	+	+	+	7	Moderate
Hulko W 2009 [63]	+	+	+	+	+	–	+	+	+	8	Moderate
Johannessen A et al. 2011 [64]	+	+	+	+	+	–	+	+	+	8	Moderate
Johannessen A et al. 2014 [65]	+	+	+	+	+ −	–	+	+	+	8	Moderate
Karlsson E et al. 2014 [66]	+	+	+	+	+	–	+	+	+	8	Moderate
Keller HH et al. 2010 [67]	+	+	+	+	+	+	–	+	+	8	Moderate
Langdon SA et al. 2007 [68]	+	+	+	+	+	+	+	+	+	9	High
Lawrence RM et al. 2009 [69]	+	+	+	+	+	+	+	+	+	9	High
Lee SM et al. 2014 [70]	+	+	+	+	+	–	+	–	+	7	Moderate
Mac Kinley E 2009 [71]	+	+	+	+	+	–	+	+	+	8	Moderate
MacRae H 2011 [72]	+	+	+	+	+	+	+	+	+	9	High
Mazaheri M et al. 2013 [73]	+	+	+	+	+	+	+	+	+	9	High
Merrick R et al. 2016 [74]	+	+	+	+	+	–	–	+	+	7	Moderate
Mjørud M et al. 2017 [75]	+	+	+	+	+	–	+	+	+	8	Moderate
Molyneaux VJ et al. 2011 [76]	+	+	+	+	+	+	+	+	+	9	High
Mushi D et al. 2014 [77]	+	+	–	+	+	–	+	+	+	7	Moderate
Nowell ZC et al. 2013 [78]	+	+	+	+	+	+	+	+	+	9	High
Nygård L 2008 [79]	+	+	+	+	+	–	–	+	+	7	Moderate
Pesonen HM et al. 2013 [80]	+	+	+	+	+	–	+	+	+	8	Moderate
Phinney A 2011 [81]	+	+	+	+	+	–	+	+	+	8	Moderate
Pipon-Young FE et al. 2012 [82]	+	+	+	+	+	–	+	+	+	8	Moderate
Read ST et al. 2017 [83]	+	+	+	+	+	–	+	+	+	8	Moderate
Roach P et al. 2016 [84]	+	+	+	+	+	–	+	+	+	8	Moderate
Rostad D et al. 2013 [85]	+	+	+	+	+	–	+	+	+	8	Moderate
Sandberg L et al. 2017 [86]	+	+	+	+	+	–	+	+	+	8	Moderate
Sharp BK 2017 [19]	+	+	+	+	+	–	+	–	+	7	Moderate
Sixsmith A and Gibson G 2007 [87]	+	+	+	+	+	–	+	+	+	8	Moderate
Stephan A et al. 2018 [88]	+	+	+	+	+	–	+	+	+	8	Moderate
Svanström R et al. 2015 [89]	+	+	+	+	+	–	+	+	+	8	Moderate
Tak SH et al. 2015 [90]	+	+	+	+	+	–	+	+	+	8	Moderate
Tolhurst E and Weicht B 2017 [91]	+	+	+	+	+	+	+	+	+	9	High
Thein et al. 2011 [92]	+	+	+	+	+	–	+	–	+	7	Moderate
van Vliet D et al. 2017 [20]	+	+	+	+	+	–	+	+	+	8	Moderate
Van Zadelhoff E et al. 2011 [93]	+	+	+	+	+	–	+	+	+	8	Moderate
Vernooij-Dassen M et al. 2006 [94]	+	+	+	+	+	–	–	+	+	7	Moderate
Vikström S et al. 2008 [95]	+	+	+	+	+	–	–	+	+	7	Moderate
Weaks D et al. 2015 [96]	+	+	+	+	+	+	+	+	+	9	High
Wolverson EL et al. 2010 [97]	+	+	+	+	+	–	–	+	+	7	Moderate
Öman A and Nygård L 2005 [98]	+	+	+	+	+	–	–	+	+	7	Moderate

^a CASP criteria 1.Clear research statement, 2.Qualitative methodology, 3.Research question appropriate, 4.Recruitment strategy, 5.Data collection, 6.Relationship researcher – participants described adequately, 7.Ethical considerations, 8.Data analysis, 9.Clear statements of findings