TABLE 2.

Quality assessment “QualSyst” according to Kmet et al. (2004).

Study	Question described	Appropriate study design	Appropriate participant selection	Characteristics described	Random allocation	Researchers blinded	Participants blinded	Outcome measures well defined and robust to bias	Sample size appropriate	Analytic methods well described	Estimate of variance reported	Controlled for confounding	Results reported in detail	Conclusion supported by results	Rating
Alkozei et al. (2016)	2	1	1	2	0	N/A	N/A	2	1	2	2	1	2	2	strong
An et al. (2009)	2	1	2	2	0	N/A	N/A	2	1	2	1	1	2	2	strong
Ayaki et al. (2016)	2	2	2	2	0	0	0	2	0	1	1	0	2	2	moderate
Baek and Min (2015)	2	2	1	2	0	N/A	N/A	2	1	2	2	1	2	2	strong
Beaven and Ekström (2013)	2	2	1	2	1	1	1	2	1	2	1	1	2	2	strong
Bowler and Bourke (2019)	2	2	2	1	1	0	N/A	1	2	2	2	1	2	2	strong
Burkhart and Phelps (2009)	2	2	2	2	2	1	N/A	2	1	2	2	1	2	2	strong
Cajochen et al. (2011)	2	2	2	2	0	0	2	2	0	2	1	1	2	2	moderate
Chang et al., (2015)	2	2	2	2	1	N/A	N/A	2	0	2	2	0	2	1	strong
Chellappa et al. (2013)	2	2	1	2	0	2	N/A	2	2	2	2	0	2	1	strong
Chindamo et al. (2019)	1	2	2	2	N/A	N/A	N/A	1	2	2	1	2	2	2	strong
Driller and Uiga (2019)	2	2	1	2	1	N/A	N/A	2	1	2	2	2	2	2	strong
Ekström and Beaven (2014)	2	2	2	2	1	1	2	1	1	2	2	0	2	1	strong
Gabel et al. (2013)	2	2	2	2	0	N/A	1	2	1	2	1	1	2	2	strong
Grønli et al. (2016)	2	2	0	2	2	2	N/A	2	1	2	1	1	2	1	strong
Figueiro et al. (2009)	2	2	1	2	0	N/A	N/A	2	1	2	2	1	2	2	strong
Heath et al. (2014)	2	2	2	2	0	0	0	2	0	2	1	2	2	1	moderate
Heo et al. (2017)	2	2	2	2	1	1	2	2	0	2	2	1	2	1	strong
Iskra-Golec et al. (2012)	2	2	2	2	0	0	0	1	1	2	0	1	2	1	moderate
Knaier et al. (2017a)	2	2	2	2	1	2	1	2	1	2	2	0	2	2	strong
Knufinke et al. (2018)	1	1	2	2	N/A	N/A	N/A	1	2	2	2	1	2	2	strong
Lehrl et al. (2007)	2	2	1	1	0	0	1	1	1	2	1	1	2	2	moderate
Lockley et al. (2006)	2	2	2	2	1	0	0	2	0	2	1	1	2	2	moderate
Motamedzadeh et al. (2017)	2	2	2	2	0	N/A	N/A	2	1	1	1	0	2	2	moderate
Münch et al. (2016)	2	2	2	2	1	N/A	1	2	0	2	2	1	2	2	strong
Phipps-Nelson et al. (2009)	2	1	2	2	0	N/A	2	2	1	2	1	0	2	1	moderate
Rångtell et al. (2016)	2	2	2	2	1	N/A	N/A	2	0	2	2	0	2	1	strong
Sahin and Figueiro (2013)	2	2	2	2	1	N/A	N/A	2	1	2	1	0	2	2	strong
Scheuermaier et al. (2018)	2	1	2	2	0	0	0	2	0	2	1	1	2	2	moderate
Slama et al. (2015)	2	2	2	2	1	0	N/A	2	0	2	1	1	2	2	moderate
Sander et al. (2015)	2	2	2	1	2	N/A	N/A	1	1	2	2	0	2	1	strong
Taillard et al. (2012)	2	2	2	2	2	2	2	2	1	2	2	0	2	2	strong
Tulppo et al. (2014)	2	2	2	2	1	2	2	2	0	2	1	1	2	1	strong
Van Der Lely et al. (2015)	2	2	2	2	0	N/A	N/A	2	1	2	2	1	2	2	strong
Viola et al. (2008)	2	2	1	2	0	0	2	1	2	2	2	1	1	2	moderate
Yang et al. (2018)	2	2	2	2	0	0	0	2	0	1	1	0	2	2	moderate

N/A not applicable, 2 indicates yes, 1 indicates partial, 0 indicates no; Quality scores: >75% strong, 55% ≥ 75% moderate, <55% weak.