Table 1.

Summary of risk of bias, indicating the risk of bias for each domain in each study.

	Random sequence generation (selection bias)	Allocation concealment (selection bias)	Blinding of participants and personnel (performance bias)	Blinding of outcome assessment (detection bias) (patient-reported outcomes)	Blinding of outcome assessment (detection bias) (all-cause mortality)	Incomplete outcome data (attrition bias) (short-term [2–6 weeks])	Incomplete outcome data (attrition bias) (long term [>6 weeks])	Selective reporting (reporting bias)
Zamparo 2005 [18]	+	+	+	+	?	+	?	+
Knechtle 2008 [41]	?	?	+	+	+	+	?	+
Knechtle 2010 A [42]	?	?	+	+	+	+	?	?
Knechtle 2010 B [43]	?	?	+	+	+	+	?	+
Pyne 2014 [2]	+	+	+	?	+	?	+	+
Shaw 2014 [19]	+	+	+	?	+	?	+	?
VanHeest 2014 [44]	+	+	+	?	+	?	+	?
Domínguez 2017 [7]	-	?	+	?	+	?	+	?
Zamparo 2020 [45]	-	?	+	?	+	?	+	?
Jiménez-Alfageme 2022 [25]	?	+	+	+	+	?	+	?
Ben-Zaken 2022 [1]	-	?	+	?	+	-	?	?

Green represents a negligible risk of bias; yellow represents an unclear risk of bias; red represents a substantial risk of bias.