Table 1 Quality index assessment scale ratings
Study | Reporting | External validity | Internal validity—bias | Internal validity—confounding | Power | QI score |
|---|---|---|---|---|---|---|
Full score, 11 | Full score, 3 | Full score, 7 | Full score, 6 | Full score, 1 | Full score, 28 | |
Blair et al., 2014 [54] | 7 | 2 | 5 | 4 | 0 | 18 |
Brown et al., 2000 [55] | 8 | 3 | 5 | 3 | 0 | 19 |
Dawe et al., 1995 [56] | 7 | 3 | 5 | 4 | 0 | 19 |
DeVito et al., 2003 [57] | 6 | 3 | 5 | 2 | 0 | 16 |
Lam et al., 2011 [58] | 8 | 2 | 4 | 3 | 0 | 17 |
Li et al., 2005 [59] | 8 | 3 | 5 | 2 | 0 | 18 |
Mangione et al., 1999 [60] | 8 | 3 | 5 | 3 | 0 | 19 |
Means et al., 1996 [61] | 9 | 3 | 4 | 2 | 0 | 18 |
Morey et al., 2009 [62] | 7 | 2 | 6 | 3 | 0 | 18 |
Morgan et al., 2004 [63] | 8 | 3 | 5 | 3 | 0 | 19 |
Motl et al., 2005 [64] | 6 | 3 | 4 | 2 | 0 | 15 |
Rosie et al., 2007 [65] | 9 | 3 | 5 | 2 | 0 | 19 |
Schnelle et al., 2003 [66] | 8 | 3 | 6 | 3 | 0 | 20 |
Singh et al., 2005 [67] | 8 | 3 | 6 | 3 | 0 | 20 |
Wolfson et al., 1996 [68] | 9 | 3 | 5 | 3 | 0 | 20 |