Table 3.

Risk of bias assessment of non-randomized controlled studies

Risk of bias	Confounding	Patient selection	Classification of intervention	Deviations from the intended interventions	Missing data	Outcome measurement	Selection of the reported results	Overall risk of bias
D’Ascenzo et al. [20]	Moderate	Moderate	Low	Low	Low	Low	Moderate	Moderate
Di Giorgio et al. [17]	Critical	Critical	Low	Low	Moderate	Low	Moderate	Critical
Iannaccone et al. [21]	Moderate	Moderate	Low	Low	Low	Low	Moderate	Moderate
Khalifa et al. [22]	Serious	Critical	Low	Low	Low	Serious	Moderate	Critical
Sheth et al. [19]	Moderate	Moderate	Low	Low	Moderate	Low	Low	Moderate