Schäfer 1996.

Methods	Quasi‐randomised trial
Participants	54 OCTR (13 men, 41 women), 47 ECTR (17 men, 30 women); mean age 53 years
Interventions	1‐portal ECTR (Agee) vs OCTR
Outcomes	Follow‐up at 9 months Complications, grip strength, return to work
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quasi‐randomised, according to the day of the week (odd or even)
Allocation concealment (selection bias)	High risk	Quasi‐randomised, according to the day of the week (odd or even)
Blinding of participants and personnel (performance bias) All outcomes	High risk	No information given. Participants and personnel could not be blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	No information given. Participants and personnel could not be blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No participants lost to follow‐up
Selective reporting (reporting bias)	Unclear risk	No P values and SDs of all outcomes
Other bias	Unclear risk	No baseline differences. No information given on financial support