Study designs of evaluations included in the review
The authors did not state what types of studies were eligible for the review. The studies included in the review were systematic reviews, randomised controlled trials (RCTs), uncontrolled trials, diagnostic cohort studies, case-control studies and retrospective analyses of medical charts.
Specific interventions included in the review
For people at normal risk of CRC, studies were eligible for inclusion in the review if they assessed: multiphase screening with the Hemoccult test as the first phase; multiphase screening with sigmoidoscopy; or uniphase screening with colonoscopy. For people at a higher risk of CRC, studies were eligible for inclusion if they assessed: flexible sigmoidoscopy for people with familial adenomatous polyposis; colonoscopy for people at risk of hereditary nonpolyposis colon cancer; or colonoscopy for people with immediate family history of polyps or CRC.
Reference standard test against which the new test was compared
The authors did not define a 'gold' standard comparator as an inclusion criterion. Some studies included in the review used colonoscopy as the gold standard comparator. Others used clinical follow-up to assess mortality and faecal occult blood testing (FOBT) to assess sensitivity and specificity.
Participants included in the review
Studies were eligible for inclusion if they involved people at normal or above average risk of CRC, including people with familial or personal history of the disease. The participants' ages varied between the studies (range: 35 to 80 years). Most of the participants were out-patients.
Outcomes assessed in the review
Studies were eligible for inclusion if they included data on the rates of cancer detection, cancer mortality, adherence, feasibility, or test accuracy. Sensitivity, specificity, positive predictive value, risk ratios and incidence ratios were presented for the individual studies.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.