TABLE 2.

Quality assessment ‘Qualsyst’.

Study	Question	Study design	Subject selection	Characteristics	Randomization	Blinded researchers	Blinded subjects	Outcome	Sample size	Analysis	Variance	Confounding	Results detail	Conclusion	Rating (%)
Zia et al. (2022)	2	2	1	2	0	0	0	2	2	1	1	1	2	2	81.82%
Gimunová et al. (2020)	2	2	1	2	1	0	0	2	2	2	1	1	2	2	83.33%
Bagwell et al. (2020)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Forczek et al. (2019)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Christensen et al. (2019)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Ramachandra (2018)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Krkeljas (2018)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Kerbourc’h et al. (2017)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
ElDeeb et al. (2016)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Błaszczyk et al. (2016)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Branco et al. (2013)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Lymbery and Gilleard (2005)	2	2	1	2	0	0	0	2	2	2	2	1	2	2	90.91%
Bird et al. (1999)	2	2	1	2	0	0	0	2	2	2	2	1	2	2	90.91%
Branco et al. (2016)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Foti et al. (2000)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Bertuit et al. (2015)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Carpes et al. (2008)	2	2	1	2	0	0	0	2	1	2	1	1	2	2	81.82%
Forczek and Staszkiewicz (2012)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Wu et al. (2010)	2	2	1	2	0	0	0	2	1	2	1	1	2	2	81.82%
Gilleard (2013)	2	2	1	2	0	0	0	2	2	2	1	1	2	2	86.36%
Rothwell et al. (2020)	2	2	2	1	0	0	0	2	2	2	1	1	2	2	86.36%

Scoring: 2 = Yes, 1 = Partial, 0 = Not applicable; Quality levels: ≥75% High, 55%–74% Moderate, ≤55% Low.