Table 4.

Quality appraisal results of included studies.

Author	Date	Country	Abstract and title	Introduction and aims	Method and data	Sampling	Data analysis	Ethics and bias	Findings/results	Transferability/generalizability	Implications and usefulness	Quality appraisal classification	Quality appraisal percentage
Caris et al	2018	USA	Good	Good	Good	Fair	Good	Fair	Good	Fair	Good	High	92%
Azhar et al.	2016	Saudi Arabia	Good	Good	Fair	Poor	Poor	Poor	Good	Poor	Good	High	75%
Havermans et al.	2015	Belgium	Fair	Good	Good	Poor	Good	Good	Good	Poor	Good	High	86%
Redshaw and Wilson	2012	Australia	Poor	Poor	Good	Poor	Good	Fair	Good	Poor	Good	High	75%
Mughal et al.	2011	Lahore	Good	Fair	Good	Poor	Good	Fair	Good	Poor	Very poor	High	75%
Wray and Maynard	2005	UK	Good	Fair	Good	Poor	Good	Fair	Poor	Poor	Good	High	78%
Janus and Goldberg	1997	Canada	Fair	Fair	Fair	Poor	Poor	Fair	Fair	Poor	Good	Medium	69%
Williams et al.	1993	Philippines	Poor	Good	Good	Poor	Fair	Fair	Good	Poor	Good	High	78%
Menke	1987	USA	Poor	Good	Good	Poor	Good	Poor	Good	Poor	Good	High	78%
Lavigne and Ryan	1979	USA	Fair	Good	Good	Fair	Poor	Poor	Fair	Fair	Fair	High	75%
Apley et al.	1967	UK	Very poor	Very poor	Poor	Poor	Poor	Very poor	Poor	Very poor	Poor	Low	39%