Ohlsson 1995

Methods	RCT Accrual: 1983 to 1986 Single centre trial Setting: tertiary Follow‐up: 66 to 105.6 months
Participants	107 participants (51 men, 56 women) undergoing resection with curative intent for CRC at the departments of surgery in Lund and Helsingborg, Sweden, from 1983 to 1986 Exclusion criteria Local excision only Distant metastases Participants in whom age or severe illness was considered to preclude treatment of recurrent disease Inability to co‐operate Crohn's disease Ulcerative colitis Familial polyposis Incomplete colonoscopy together with uncertain findings at barium enema examination Dukes' A: 19 Dukes' B: 47 Dukes' C: 41 Colon primary: 71 Rectal primary: 36 Country: Finland Setting: hospital
Interventions	The experimental group were seen at 3‐, 6‐, 9‐, 12‐, 15‐, 18‐, 21‐, 24‐, 30‐, 36‐, 42‐, 48‐, and 60‐month intervals. Performed at each visit were clinical exam, rigid proctosigmoidoscopy, CEA, alkaline phosphatase, gamma‐glutaryl transferase, faecal haemoglobin, and CXR. Examination of anastomosis (flexible sigmoidoscopy or colonoscopy, as dictated by the lesion) was performed at 9, 21, and 42 months. Colonoscopy was performed at 3, 15, 30, and 60 months. CT of the pelvis was performed at 3, 6, 12, 18, and 24 months. The control group had no follow‐up visits planned. They received written instructions recommending that they leave faecal samples with the district nurse for examination every third month during the first 2 years after surgery then once a year. They were instructed to contact the surgical department if they had any symptoms.
Outcomes	Overall survival Local recurrence Anastomotic recurrence Symptomatic recurrence Resection with curative attempt Time to first recurrence Protocol compliance
Notes	Local recurrence: recurrence within the initial bed, operative field, anastomosis, or structures contiguous or adherent to the primary (included relapse in the abdominal wound, drain site, pelvis, or perineum) Anastomotic recurrence: intraluminal recurrence within 5 cm of the anastomosis Symptomatic: when symptoms could be related to the participant's initial illness and when they resulted in or would have resulted in the participant seeking advice Resection with curative attempt: all visible removed, microscopic‐free margins Time to first recurrence: interval between primary surgery and unequivocal demonstration of recurrence at laparotomy, imaging, or autopsy
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were randomised to..." Comment: the study provided no details about sequence generation; therefore, we judged this as unclear.
Allocation concealment (selection bias)	Unclear risk	The paper provided no details, so we judged this as unclear.
Blinding of participants and personnel	Low risk	Quote (page 620): "No follow‐up visits were planned for patients in the control group. They received written instruction, recommending they leave fecal samples with the district nurse for examination of haemoglobin every third month during the two first years after surgery and then once a year. They were also instructed to contact the surgical department as soon as they experienced any problems with the colostomy, abdominal or perineal pain, altered bowel movements, change in fecal colour, micturition problems, or weight loss. Protocol for active follow‐up is given in Table 1." Comment: although it was not mentioned, participants received clear instructions about when they were to contact the surgical department, and the follow‐up protocols for both groups were prespecified, which would have reduced the risk of bias.
Blinding of outcome assessment	Unclear risk	The study did not mention blinding of outcome assessment; it would have been possible to blind those reporting the investigations treatment arm, but not having done so is unlikely to have introduced bias.
Incomplete outcome data (attrition and exclusions)	Low risk	Quote (page 623): "Twenty‐two of 54 patients in the control group and 15 of 53 patients in the F‐U group were dead at the end of the study..." Comment: all participants reported on attrition; there was no attrition.
Selective reporting (reporting bias)	Unclear risk	We did not have access to the study protocol, so we judged this domain at unclear risk of bias.
Other sources of bias	Unclear risk	We detected no other bias.