Table 2. Risk of bias assessment for randomised controlled trials (RCTs) and observational studies.

Author & Year	Study design	Tool used	Randomisation/Allocation	Blinding/Deviations	Missing outcomes	Outcome measurement/Reporting	Other domains	Overall risk of bias
Thijs et al. (2025) [13]	Multicenter RCT	Cochrane RoB 2	Low	Low	Low	Low	—	Low risk
Ralph et al. (2020) [14]	Phase I/II RCT	Cochrane RoB 2	Some concerns	Low	Low	Some concerns	—	Some concerns
Tobinick et al. (2012) [9]	Observational cohort	Newcastle–Ottawa Scale (NOS)	Few	Few	Few	Few	Short follow-up period	High risk