Critical appraisal:Taylor GW, Jayne DG, Brown SR, Thorpe H, Brown JM, Dewberry SC, et al 2010 2
From Cancer Guidelines Wiki
Risk of bias assessment: Randomised Controlled Trial (Cochrane risk of bias tool)
Random sequence generation
Describe the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.
- "Patients were randomly allocated to receive either laparoscopic or open surgery at a two-to-one ratio, to allow for anticipated conversions (ie, from laparoscopic to open surgery) and to provide as much information as possible on laparoscopic surgery. Randomisation was stratified by surgeon, proposed site of operation, presence of liver metastases, and preoperative radiotherapy administration..."
Note: "a multi-level model was fitted to account for any surgeon effect and for stratification factors... Because sensitivity analyses or adjustment for surgeon and stratification factors made little difference to conclusions, the analyses presented were therefore unadjusted."
Restricted randomisation stratified by site (in particular) increases chance of bias, however, this was accounted for in analysis and made little difference.
What was the risk of bias from the random sequence generation?
- Unclear
Allocation concealment
Describe the method used to conceal the allocation sequence in sufficient detail to determine whether intervention allocations could have been foreseen in advance of or during, enrolment.
- "...this process was done by telephone by the trial coordinator at the Clinical Trials Research Unit, University of Leeds, Leeds, UK."
Central allocation used.
What was the risk of bias from the allocation concealment?
- Low
Blinding
Describe all measures used, if any, to blind outcome assessors from knowledge of which intervention a participant received. Provide any information relating to whether the intended blinding was effective.
- "randomised, controlled, open, parallel-group trial"
No blinding, likely to effect outcome.
What was the risk of bias from the blinding of participants and personnel and outcome assessors?
- High
Incomplete outcome data
Describe the completeness of outcome data for each main outcome, including attrition and exlusions from the analysis. State whether attrition and exclusions were reported, the numbers in each intervention group (compared with total randomized participants), reasons for attrition/exclusions where reported, and any re-inclusions in analyses performed by the review authors.
- Long term complications: Well defined reasons for exclusion from analysis, 383 excluded but reasons not likely to impact on outcome.
What was the risk of bias from incomplete outcome data?
- Unclear
Selective outcome reporting
State how the possibility of selective outcome reporting was examined by the review authors and what was found.
- Long term complications: Not outlined in original protocol
What was the risk of bias from selective outcome reporting? Assessments should be made for each main outcome (or class of outcomes).
- High
Other sources of bias
Describe any other sources of bias
- Does not detail how outcome data was measured for ITT px (eg, imputation).
What was the risk of bias from other sources?
- High
Overall risk of bias
| Unclear risk of bias | Additional comments: Please replace this text and include any additional comments in regards to your risk of bias rating |
This appraisal has been completed.
- Article
- Taylor GW, Jayne DG, Brown SR, Thorpe H, Brown JM, Dewberry SC, et al. Adhesions and incisional hernias following laparoscopic versus open surgery for colorectal cancer in the CLASICC trial. Br J Surg 2010 Jan;97(1):70-8 Available from: http://www.ncbi.nlm.nih.gov/pubmed/20013936.
- Assigned to
- User:Victoria.freeman
- Topic area
- Guidelines:Colorectal cancer
- Clinical question
- Form
- Form:Quality appraisal rct-cochrane
- Outcomes
- Long term complications
Section below only relevant for Cancer Council Project Officer