Colonoscopy Recommendation May Cut Adherence to CRC Screening

John M. Inadomi, MD

Patients are less likely to complete colorectal cancer (CRC) screening if their physician recommended colonoscopy rather than recommending fecal occult blood testing (FOBT) or allowed patients to decide between colonoscopy or FOBT, new data show.

The results also revealed significant racial/ethnic differences in screening completion.

John M. Inadomi, MD, Cyrus E. Rubin Professor of Medicine and head of the Gastroenterology Division, University of Washington, Seattle, and coworkers conducted a study to determine the effects of recommending FOBT or colonoscopy or offering patients a choice between FOBT and colonoscopy on the completion of CRC screening in persons at average risk for CRC.

Several studies have shown that multiple CRC screening strategies can decrease CRC incidence and mortality, the researchers observed. However, adherence to screening is poor, especially among racial and ethnic minorities. No prior study in the United States has compared patient adherence to competing CRC strategies.

The team used clinic time block as the unit of randomization, and every three months randomized primary care providers to a different initial screening recommendation: FOBT, colonoscopy, or a choice between the two methods.

The study included 997 patients age 50 to 79 years who received their medical care through the public healthcare system of the City and County of San Francisco. The group was racially and ethnically diverse.

The primary outcome measure was the completion of a CRC screening strategy within 12 months of enrollment. Completion of CRC screening was defined as documented performance of colonoscopy or the receipt of three FOBT test cards containing stool specimens plus colonoscopy for any positive FOBT result.

Overall, 58% of participants completed the CRC screening strategy to which they were assigned or had chosen within 12 months of enrollment. Specifically, 38% of patients who were recommended colonoscopy completed screening compared with 67% of patients who were recommended FOBT (P <.001) and 69% of patients who were allowed to choose between FOBT or colonoscopy (P <.001).

White patients more frequently completed colonoscopy and nonwhite patients more frequently completed FOBT. Overall, Latino and Asian patients completed screening more often than black patients.

The investigators said that language preference may account for some of the differences in CRC screening completion rates. For example, Latinos who preferred to speak Spanish and Asians who preferred Cantonese or Mandarin had higher screening completion rates than patients with the same racial/ethnic background who preferred to speak English.

The authors cautioned that their results were drawn from a single safety-net healthcare system, and therefore do not necessarily apply to other populations.

Inadomi JM, Vijan S, Janz NK, et al. Adherence to colorectal cancer screening. A randomized clinical trial of competing strategies. Arch Intern Med. 2012;172(7):575-582.