Table 3.

Risk of bias assessment for individual studies using the “Risk Of Bias In Non-randomised Studies - of Interventions” tool (ROBINS-I).

Author	Confounding	Participant Selection	Classification of Interventions	Deviations from Intended Intervention	Missing Data	Measurement of Outcomes	Selection of the Reported Result	Overall
Abrahamsson [10]	Serious	Serious	Low	Serious	Low	Moderate	Low	Serious
Ahlgren [16]	Serious	Serious	Low	Moderate	Low	Low	Low	Serious
Bostwick [11]	Serious	Serious	Low	Serious	Low	Moderate	Moderate	Serious
Bubendorf [14]	Serious	Serious	Low	Moderate	Low	Low	Moderate	Serious
Cohen [15]	Serious	Serious	Low	Serious	Low	Moderate	Low	Serious
Gunia [17]	Serious	Serious	Low	Serious	Low	Moderate	Low	Serious
Heinrich [13]	Serious	Serious	Low	Serious	Low	Low	Moderate	Serious
Ishida [12]	Serious	Serious	Low	Serious	Low	Moderate	Moderate	Serious
Krupski [18]	Serious	Serious	Low	Serious	Low	Moderate	Moderate	Moderate
Ma [19]	Serious	Serious	Low	Low	Low	Moderate	Low	Serious
Noordzij [25]	Serious	Serious	Low	Moderate	Low	Low	Moderate	Serious
Revelos [20]	Moderate	Serious	Low	Serious	Low	Low	Moderate	Serious
Theodorescu [24]	Serious	Moderate	Low	Serious	Low	Moderate	Low	Serious
Veltri [21]	Serious	Serious	Low	Serious	Low	Low	Moderate	Serious
Weinstein [22]	Moderate	Moderate	Low	Moderate	Low	Moderate	Low	Moderate
Genitsch [23]	Serious	Serious	Low	Serious	Low	Moderate	Moderate	Serious