Table 2.

Outcomes of the methodological appraisal

	Burton, 2016 [56]	Foti, 2005 [57]	Foti, 2005 [58]	Smits, 2015 [59]
Abstract & title	Poor 2	Fair 3	Fair 3	Poor 2
Introduction & aims	Fair 3	Good 4	Good 4	Poor 2
Method & data	Fair 3	Fair 3	Fair 3	Poor 2
Sampling	Poor 2	Good 4	Fair 3	Poor 2
Data analysis	Poor 2	Fair 3	Good 4	Very poor 1
Ethics & bias	Very poor 1	Very poor 1	Very poor 1	Very poor 1
Results & findings	Fair 3	Fair 3	Fair 3	Poor 2
Transferability & generalizability	Poor 2	Good 4	Good 4	Fair 3
Implications	Poor 2	Fair 3	Fair 3	Fair 3
Total score/ quality	20 ‘Fair’	28 ‘Good’	28 ‘Good’	18 ‘Poor’