Table 1.

Evaluation of bias in articles included in present review using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool

Bias domain	Vigushin et al. 1998 [22]	Ripple et al. 1998 [23]	Ripple et al. 2000 [24]	Bailey et al. 2008 [25]	Miller et al. 2013 [26]
Pre-intervention
Confounding	low	low	low	low	low
Selection of participants	low	low	low	low	low
At intervention
Classification of intervention	low	low	low	low	low
Post intervention
Deviation from intended intervention	low	low	low	Serious	low
Missing data	low	low	low	low	low
Measurement of outcomes	low	low	low	low	low
Selection of reported results	low	low	low	low	low
Overall	low	low	low	Serious	low