Table 2.

Main issues arisen from the quality appraisal of the included studies.

Issue	References
Quantitative studies
Study subject and setting not described in sufficient detail	Abbott & Pachucki, 2017; Abbott et al., 2017; De Rooij et al., 2012; Kok et al., 2018; Wolf-Ostermann et. al., 2012; Weyerer et al., 2010
Small sample size	Wood et al., 2005
No strategies to deal with (possible) confounding factors stated	Abbott & Pachucki, 2017; Abbott et al., 2017; Morgan-Brown et al., 2013; Wood et al., 2005
Outcomes not measured before the intervention was introduced	De Boer, Hamers, Zwakhalen, Tan, Beerens, & Verbeek, 2017a; De Rooij et al., 2012; Verbeek et al., 2010
Qualitative studies
Congruity between research methodology and data collection is not made explicit	Doyle et al., 2012; Moore, 1999; Moore & Verhoef, 1999
Agreement between research methodology and data analysis is not made distinct	Aasgaard et al., 2017
Connection between research methodology and the interpretation of results is not clear	Aasgaard et al., 2017; Moore, 1999; Moore & Verhoef, 1999