Table 3.

Percentage of studies scoring ‘Yes’ for quality assessment criteria (Kmet et al. [31]; Collins et al. [32])

Criteria		n	%
Qualitative Criteria
1	Question/objective sufficiently described?	21	100
2	Study design evident and appropriate?	21	100
3	Context for the study clear?	20	95
4	Connection to a theoretical framework / wider body of knowledge?	21	100
5	Sampling strategy described, relevant and justified?	4	19
6	Data collection methods clearly described and systematic?	4	19
7	Data analysis clearly described and systematic?	4	19
8	Use of verification procedure(s) to establish credibility?	3	14
9	Conclusions supported by the results?	19	90
10	Reflexivity of the account?	6	29
Quantitative Criteria
1	Question / objective sufficiently described?	4	100
2	Study design evident and appropriate?	4	100
3	Method of subject/comparison group selection or source of information/input variables described and appropriate?	4	100
4	Subject (and comparison group, if applicable) characteristics sufficiently described?	N/A	N/A
5	If interventional and random allocation was possible, was it described?	N/A	N/A
6	If interventional and blinding of investigators was possible, was it reported?	N/A	N/A
7	If interventional and blinding of subjects was possible, was it reported?	N/A	N/A
8	Outcome and (if applicable) exposure measure(s) well defined and robust to measurement / misclassification bias? Means of assessment reported?	3	100
9	Sample size appropriate?	4	100
10	Analytic methods described/justified and appropriate?	4	100
11	Some estimate of variance is reported for the main results?	4	100
12	Controlled for confounding?	4	100
13	Results reported in sufficient detail?	4	100
14	Conclusions supported by the results?	4	100

Note. Not all criteria were applicable for all studies; QAT = Quality Assessment Tool