Secco 2002

Methods	RCT (2 "studies" within 1 publication) Accrual: 1988 to 1996 Single centre trial Setting: not stated Follow‐up: 61.5 months (high‐risk group) and 48 months (low‐risk group)
Participants	337 participants (163 men and 174 women) who had curative surgery alone for colorectal cancer Participants were stratified into the following: n = 200 high‐risk: (adenocarcinoma rectum treated by low anterior resection, left colon adenocarcinoma modified Dukes B2 or T3, preoperative serum CEA greater than or equal to 7.5 ng/ml, Dukes stage C, poorly differentiated grade, mucinous adenocarcinoma, or signet ring cells) n = 158 low‐risk: participants had none of these characteristics Country: Italy
Interventions	108 high‐risk participants were randomised to "intensive follow‐up" (experimental arm); they had clinic visits and serum CEA, abdomen/pelvic US scans, and CXR. Participants with rectal carcinoma had rigid sigmoidoscopy and CXR. 84 high‐risk participants were randomised to a "minimal follow‐up programme performed by physicians".
Outcomes	Overall survival (actuarial at 5 years) Recurrence Costs Curative reoperations
Notes	Curative surgery: "macroscopic excision of primary, peri‐rectal tissues and nodes" Experimental arm: clinic visits and serum CEA measured at 3, 6, 9, 12, 15, 18, 21, 24, 28, 32, 36, 42, 48, 54, and 60 months; abdomen/pelvic US scans at 6, 12, 18, 24, 30, 36, 48, and 60 months; CXR at 12, 24, 36, 48, and 60 months. Participants with rectal carcinoma had rigid sigmoidoscopy and CXR at 12, 24, 36, 48, and 60 months. Participants with rectal carcinoma had rigid sigmoidoscopy and CXR at 12, 24, 36, 48, and 60 months. All participants received education regarding follow‐up and the signs and symptoms of possible recurrence. All were expected to phone the surgical team every 6 months.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (page 419): "Patients of each group were randomly included..." Comment: the study provided no details regarding sequence generation; therefore, we judged this domain to be at unclear risk of bias.
Allocation concealment (selection bias)	Unclear risk	The paper provided no description of allocation concealment.
Blinding of participants and personnel	Unclear risk	The study did not mention blinding of participants and personnel. As participants in each arm were educated about signs and symptoms of a possible recurrence, it is possible that those allocated to the minimal arm might be more likely to report symptoms in the knowledge that they would not have any investigations performed in the absence of symptoms. This may have introduced bias; therefore, we judged this at high risk of bias. The lack of blinding for personnel is less likely to have caused bias, because the follow‐up schedule was prespecified for both arms.
Blinding of outcome assessment	Low risk	The study did not mention blinding of outcome assessment; it would have been possible to do so, but unlikely to have introduced bias.
Incomplete outcome data (attrition and exclusions)	Unclear risk	Quote (paragraph 2, page 419): "Of the initial 358 patients...definitive randomisation of 337 patients" Comment: it is not clear whether these were prerandomisation or postrandomisation exclusions; we judged this domain to be at unclear risk of bias. Attrition: quote (paragraph 1, page 419): "Twenty‐one (5.8%) patients dropped out over the first 13 months: eight cases from group 1 and 13 from Group 2." Comment: although the reasons for attrition were not reported, those who dropped out were reported by study arm, and as the numbers were similar, we judged this domain to be at low risk of bias.
Selective reporting (reporting bias)	Unclear risk	We did not have access to the study protocol, so we judged this domain to be at unclear risk of bias.
Other sources of bias	Unclear risk	We detected no other bias.