Table 3.

Quality assessment scores of selected comparative studies, with Newcastle-Ottawa Scale (modified for cross-sectional)

STUDY	SELECTION (maximum 5 Stars)	COMPARABILITY (maximum 2 Stars)	OUTCOME ASSESSMENT (maximum 3 Stars)	TOTAL (maximum 10 Stars)
Brown et al. 2011 [30]	1	0	1	2
Brown et al. 2011 [11]	1	1	1	3
Townsend et al. 2012 [24]	1	0	1	2
Cameron et al. 2013 [25]	3	2	1	6
Moore et al., 2014 [38]	1	1	1	3
Brown et al. 2013 [12]	2	2	1	5
Brown 2016 [40]	1	2	1	4
Cameron et al. 2015 [29]	2	0	1	3
Morison et al. 2016 [31]	1	0	1	2
Brown et al. 2017 [26]	1	2	1	4