Table 2.

Assessment of study quality by QualSyst ratings [29] and NHMRC Evidence Hierarchy [30]

Reference	Kmet score (%)	Methodological qualitya	NHMRC level of evidence
Bhattacharyya et al. [18]	18/22 (82 %)	Good	III
Bisch et al. [17]	20/24 (83 %)	Good	III
Bogaardt et al. [41]	16/22 (73 %)	Strong	III
Chen et al. [71]	13/24 (54 %)	Adequate	III
Choi et al. [49]	21/22 (95 %)	Good	III
Clavé et al. [19]	21/22 (95 %)	Good	III
Clavé et al. [54]	21/24 (88 %)	Good	III
Dantas et al. [58]	19/22 (86 %)	Good	III
Diniz et al. [60]	24/26 (92 %)	Good	II
Goulding et al. [82]	22/26 (85 %)	Good	II
Groher et al. [26]	10/24 (42 %)	Poor	III
Hind et al. [46]	13/24 (54 %)	Adequate	III
Inamoto et al. [63]	20/26 (77 %)	Strong	II
Kelly et al. [94]	16/22 (73 %)	Strong	III
Kuhlemeier et al. [66]	15/22 (68 %)	Strong	III
Leder et al. [48]	23/26 (88 %)	Good	II
Lee et al. [47]	21/22 (95 %)	Good	III
Leonard et al. [71]	21/24 (88 %)	Good	II
Matsuo et al. [78]	19/24 (79 %)	Strong	III
Rofes et al. [67]	21/24 (88 %)	Good	III
Rofes et al. [69]	21/24 (88 %)	Good	III
Stachler et al. [77]	18/22 (82 %)	Good	III
Steele and Van Lieshout [95]	17/22 (77 %)	Strong	III
Steele et al. [76]	22/24 (91 %)	Good	III
Taniguchi et al. [44]	19/22 (86 %)	Good	III
Zu et al. [57]	20/22 (91 %)	Good	III

^aMethodological quality: good >80 %; strong 60–79 %; adequate 50–59 %; poor <50 %