Table 1. Results of the quality assessment of included studies.

Study	Risk of bias				Applicability
	Representativeness	Index test	Reference test	Timing	Representativeness	Index test	Reference test
Agrawal (2014)
Akgöz (2017)
Akindele (2017)
Akinpelu (2015)
Barichella (2011)
Barzuca (2013)
Baur (2012)
Blokstra (1999)
Caleyachetty (2016)
Colchero (2014)
DeVille-Almond (2011)
Dorosty (2014)
Drumond (2012)
Duncan (2014)
El-Kassas (2016)
Faber (2005)
Gao (2017)
Griger (2015)
Harris (2016)
Hendley (2011)
Herbert (2017)
Howard (2008)
Irani (2007)
Jeffs (2016)
Johnston (2014)
Kim (2018)
Kirk (2008)
Jáuregui (2016)
Loret de Mola (2012)
Maruf (2012)
Minsky (2013)
Mogre (2014)
Mogre (2015)
Monteagudo (2015)
Moore (2010)
Mueller (2014)
Muhihi (2012)
Murillo (2016)
Peltzer (2012)
Phetla (2017)
Prinsloo (2014)
Rahman (2010)
Rouiller (2016)
Shin (2015)
Sinhababu (2007)
Strassnig (2005)
Van Minnen (2011)
Veggi (2004)
Ver Ploeg (2008)
Wang (2017)

Low risk of bias/high applicability

Rated as unclear

High risk of bias/low applicability