Study highlights need to address overuse, underuse of colorectal cancer screening tests

Only one-fifth of primary care physicians in the US follow practice guidelines for colorectal cancer screening for all the tests they recommend, according to Dr. Robin Yabroff from the National Cancer Institute and her colleagues. About 40 percent followed guidelines for some of the tests they recommended and the remaining 40 percent did not follow guidelines for any of the screening tests they recommended. Furthermore, their analysis of physician screening recommendations for colorectal cancer shows that many clinicians either overuse or underuse screening. Their findings appear online in the Journal of General Internal Medicine, published by Springer.

The theory goes that having multiple options for screening allows physicians and patients to consider the risks, benefits and other attributes of colorectal cancer screening tests to identify the option best suited to the patient. In reality, however, many adults in the US do not receive appropriate colorectal cancer screening.

To learn about colorectal cancer screening practice in the US, the authors surveyed 1,266 physicians who took part in a national survey conducted by the National Cancer Institute.

Although most physicians made guideline-consistent recommendations for initiating screening in average risk patients at age 50 and for screening intervals for individual tests, few (19 percent) made guideline-consistent recommendations for both screening initiation and screening intervals across all screening tests that they recommended. Those whose recommendations were guideline consistent tended to be younger and board certified. They were also more likely to use electronic medical records, take patients' screening preferences into account and be influenced by published clinical evidence.

Colonoscopy was the modality for which the highest proportion of physicians recommended screening more frequently than guidelines specify. It is also the most expensive colorectal screening method and the most commonly recommended. Overuse of screening may result in unnecessary follow-up testing for patients and increased risk of screening complications.

Some physicians recommended initiating screening in patients older than age 50 or at longer intervals than specified in the guidelines. Underuse of screening results in fewer earlier stage or pre-invasive cancers being detected.

Dr. Yabroff concludes: "Efforts to improve colorectal cancer screening practice should focus on factors that influence both overuse and underuse of screening and consider all recommended colorectal cancer screening modalities."