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Most People Told to Have a Colonoscopy Don't

By: MARY ANN MOON, Oncology Practice Digital Network

Apr 9, 2012

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Patients are less likely to comply with colorectal cancer screening if physicians recommend only colonoscopy than if they offer a choice of colonoscopy or fecal occult blood testing, according to a report in the April 9 issue of the Archives of Internal Medicine.

In a study of 997 middle-aged subjects at average risk of developing colorectal cancer who were making a routine visit to their primary care physician, only 38% of those advised to get a colonoscopy underwent any type of colorectal cancer screening during the ensuing year. In contrast, 67% of subjects advised to do fecal occult blood testing (FOBT) did so, and 69% of subjects who were given a choice between FOBT and colonoscopy underwent one of these types of colorectal cancer screening during the ensuing year, said Dr. John M. Inadomi of the division of gastroenterology, University of Washington, Seattle, and his associates.

No clinical trial in the United States to date has compared patient adherence to different colorectal screening strategies, and it is not known whether giving patients a choice of screening methods improves, reduces, or has no effect on adherence, they said.

Proponents of "choice" argue that increasing patients’ engagement in their health care and allowing for their individual preferences should promote adherence. But others counter that too much choice can impede adherence, with patients "defaulting to inertia" because they are confused or indecisive.

The investigators studied the issue by having primary care physicians at public health clinics randomly recommend one of three options for colorectal cancer screening to patients aged 50-79 years who were at average risk for the disease: colonoscopy only, FOBT only, or a choice between the two strategies.

The mean patient age was 58 years, and 53% of the study population were women. A total of 34% of the cohort were Hispanic, 30% were Asian (mainly Chinese), 18% were African American, 15% were white, and 4% were of other racial/ethnic backgrounds.

For FOBT, patients were given testing kits for home administration and were told to submit all three samples. Instructions were offered in the patients’ preferred language (English, Spanish, Cantonese, or Mandarin), said Dr. Inadomi, who is also at the GI health outcomes, policy, and economics research program at the University of California, San Francisco, and his colleagues.

For colonoscopy, patients were given standard information about the procedure and bowel preparation in their preferred language. Patients who agreed to colonoscopy were immediately scheduled for the procedure to be done within 2 weeks, which bypassed the preprocedure gastroenterology visit that often presents an obstacle to screening. They also were offered postprocedure transportation home, if they needed it.

Overall, 58% of the study cohort completed the colorectal cancer screening procedure that they were advised to, or chose to, do.

The proportion of patients who completed colonoscopy after being advised to undergo colonoscopy was 38.2%. This was substantially lower than the 67.2% of patients in the FOBT group who completed FOBT or the 68.8% of those in the "choice" group who completed their preferred screening method, the researchers said (Arch. Intern. Med. 2012;172:575-82).

The rate of adherence varied widely according to the study subjects’ racial/ethnic background. African Americans had the lowest overall rate of adherence (48%), while Hispanics (63%) and Asians (61%) had the highest.

Nonwhite subjects were much more likely to comply with FOBT, while whites were more likely to comply with colonoscopy.

Hispanic and Chinese patients who chose to communicate in Spanish, Cantonese, or Mandarin were more likely to adhere to screening than were those of the same ethnicity who chose to communicate in English.

The study results show that limiting the recommendation for colorectal cancer screening to colonoscopy alone actually reduces the completion rate for screening, compared with giving patients a choice between colonoscopy and FOBT.

The findings also demonstrate that "a relatively high level of adherence to colorectal cancer screening can be achieved in low-income racial/ethnic minorities when barriers to access are reduced," the investigators added.

This study was supported by the National Cancer Institute, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Center for Research Resources. The investigators reported no relevant financial disclosures.