Engel 2003.

Methods	Cohort Prospective Cross‐sectional
Participants	299 patients(192 men, 97 women) APE 54, AR 245. Patients with primary rectal cancer identified in The Munich Cancer Registry between 1996‐1998. Patients with metastatic disease excluded. Patients responding to postal questionnaire. Assessment annually for 4 years. Germany.
Interventions	Quality of life assessment with EORTC‐C30/CR38.
Outcomes	Quality of life
Notes	Evidence level: 2B. Not stated: Age, Dukes grade, tumour distance from anal verge, level of anastomosis, formation of pouch.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	High risk	Prospective cross‐sectional cohort study. Patients identified through Munich Cancer Registry. Not all eligible patients responded to questionnaire.
Blinding (performance bias and detection bias) Anterior resection or abdominoperineal resection	High risk	Blinding not possible due to surgical therapy.
Incomplete outcome data (attrition bias) Quality of life	High risk	Out of 329 included patients only 48 completed all questionnaires.
Selective reporting (reporting bias)	Low risk	All QoL data reported.