Table 2.

Results of the quality assessment for non-randomised studies using ROBINS-I tools

Study, year	Preintervention	At intervention	Post intervention					Overall risk of bias
	Bias due to confounding	Bias in selection of participants into the study	Bias in classification of interventions	Bias due to deviations from intended interventions	Bias due to missing data	Bias in measurment of outcomes	Bias in selection of the reported result
Nkenke et al 200918	Moderate	Low	Moderate	Moderate	Moderate	Serious	Moderate	Serious
Arshad et al 20139	Low	Low	Moderate	Moderate	Low	Moderate	Moderate	Moderate
Clemens et al 201519	Low	Low	Moderate	Moderate	Low	Serious	Moderate	Serious
Panwar et al 201511	Low	Low	Low	Low	Moderate	Moderate	Moderate	Moderate
Chen et al 201821	Moderate	Low	Moderate	Low	Moderate	Moderate	Low	Moderate
Yang et al 201920	Low	Low	Moderate	Moderate	Moderate	Moderate	Low	Moderate
Yalamanchi et al 202022	Low	Low	Moderate	Low	Low	Moderate	Moderate	Moderate