This review evaluated strategies to increase use of colorectal screening interventions. The authors concluded that good evidence existed to support a number of interventions in some populations. Given the potential for selection and publication biases among the included studies, it is unclear whether this conclusion can be relied upon to reflect the wider evidence base.

To evaluate strategies to increase the appropriate use of colorectal screening interventions and quality of screening discussions.

MEDLINE and The Cochrane Library were searched for published English-language articles from January 1998 to September 2009. Search terms were reported. Handsearching was also carried out.

Studies that evaluated interventions to promote use of colorectal cancer screening interventions and improve screening discussions with asymptomatic individuals not at risk of colorectal cancer and with those at risk (due to family history of colorectal cancer or polyps, or personal history of polyps at colonoscopy) were eligible for inclusion in the review. Randomised controlled trials (RCTs) and non-RCTs had to contain at least 30 participants; observational studies had to contain at least 100 participants. Outcomes of interest were colorectal cancer screening rates for colonoscopy, sigmoidoscopy (or flexible sigmoidoscopy), computed tomographic colonography (or virtual colonoscopy with only computed tomographic) and stool tests. Study location was limited to the United States.

Included studies comprised patient-level interventions (which eliminated structural barriers, one-to-one interactions, patient reminders, small media with and without decision aids and group education); provider-level interventions (physician reminders); and health care system-level interventions (improved referral processes, provision of a patient navigator). Some studies reported on multi-component interventions. All studies of patient-level interventions reported on reducing under-use of colorectal cancer screening or follow-up after receiving a positive faecal occult blood test (defined as misuse of colorectal cancer screening). Most of the included participants were enrolled in clinics or had ready access to health care and were aged 50 years or over.

Two reviewers independently selected the studies for inclusion. Disagreements were resolved by consensus.

Methodological quality of trials was assessed on randomisation, allocation concealment, blinding, baseline and maintained comparability of groups, loss to follow-up and use of intention to treat analysis. Observational studies were assessed for potential selection bias (participant selection method and loss to follow-up); measurement bias (equality, validity and reliability of outcome ascertainment); adjustment for confounders and statistical analysis. A rating of good, fair or poor was assigned to each included study. Poor-quality studies were excluded from the analyses. An overall grading was assigned to represent the strength of evidence (high, moderate, low or insufficient)

Two reviewers independently performed quality assessment. Disagreements were resolved by consensus.

Data on percentage increases in screening rates were extracted by one reviewer and checked by a second reviewer. Disagreements were resolved by consensus involving a third reviewer.

A narrative synthesis was provided.

Twenty-one studies (n=36,347) were included in the review. Twenty studies were RCTs.

Patient-level interventions (15 studies): Interventions to eliminate structural barriers (provision of faecal occult blood tests for use at home; five studies) and those that focused on one-to-one interactions (counselling using non-physician staff; three studies) showed increased screening rates from 15% to 42%. Patient reminders were associated with small to moderate increases in screening rates (5% to 15%). Study quality was graded as high. There was no statistically significant increase or mixed evidence in support of small media with or without decision aids and group education.

Health care system interventions (five studies): Increased screening rates of between 7% and 28% were found across all studies that assessed system-level interventions. Study quality was graded as high.

Provider-level interventions (two studies): Letters provided as physician reminders were associated with a 5% increase in surveillance follow up (one study). Study quality was graded as low.

There was limited evidence (one RCT) to support increased incidence of colorectal cancer screening discussions between patients and health professionals following a multi-component intervention.

There was good evidence that several interventions could improve appropriate colorectal cancer screening rates in some populations.

The review question was clear and supported by detailed inclusion criteria for all aspects except the intervention. Exclusion of poor-quality studies from the analyses meant that selection bias could not be ruled out and more positive results were highlighted. The search strategy was limited by its inclusion of published English-language articles only. These potential sources of bias were acknowledged by the authors. The review process was carried out with sufficient attempts to minimise errors and bias. Appropriate validity assessment criteria were applied to the RCTs and results of this assessment were reported in detail. Study characteristics were provided. The chosen method of synthesis appeared appropriate given the observed clinical heterogeneity. The authors' conclusion reflected the evidence provided. Given the potential for selection and publication biases, it is unclear whether this conclusion can be relied upon to reflect the wider evidence base.

Practice: The authors did not state any implications for practice.

Research: The authors stated that studies focusing on overuse and misuse of colorectal cancer screening, and those seeking to improve the quality and frequency of discussions about screening options are needed. Research is also needed on the cost-effectiveness of strategies to implement and maintain durable colorectal cancer screening programmes.

Agency for Healthcare Research and Quality: Grant No: 2902007100561. One author was supported by a grant from the American Cancer Society (CCCDA-090215-01).

Holden DJ, Harris R, Porterfield DS et al. Enhancing the use and quality of colorectal cancer screening. Rockville, MD, USA: Agency for Healthcare Research and Quality. Evidence Report/Technology Assessment no. 190. February 2010. AHRQ publication no: 10-E002.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.