Patients may not always want to stop low-value colorectal cancer screening

Veterans at one health system were asked to rate the reasonableness of using age and risk calculators in decisions about screening cessation.

Patients may be reluctant to stop low-value screening for colorectal cancer, even when the potential lack of benefit is explained, a recent study found.

Researchers at the Veterans Affairs Ann Arbor Healthcare System in Michigan surveyed veterans to assess their attitudes toward cessation of low-value screening for colorectal cancer. Screening was defined as low value if it was expected to yield little benefit based on quantitative estimates from hypothetical risk calculators. Included patients were older than age 50 years and had previously had normal results on screening colonoscopy.

The survey presented each participant with a detailed hypothetical scenario that included an explanation of age-based screening initiation and cessation and the use of risk calculators for life expectancy, risk for colorectal cancer, and overall screening benefit. Patients were asked to rate how reasonable they found it to use each concept in making screening decisions on a 7-point unidirectional Likert-type scale, where 1 indicated “not at all reasonable” and 7 indicated “extremely reasonable.” The main outcome measure was patients' response to the question, “If you personally had serious health problems that were likely to shorten your life and your doctor did not think screening would be of much benefit based on the calculator, how comfortable would you be with not getting any more screening colonoscopies?” Results were published by JAMA Network Open on Dec. 7.

The survey's response rate was 74.5% (1,054 of 1,415 potential respondents). Patients who responded to the survey had a median age range of 60 to 69 years, and most were white (85.9%) and male (94.2%). Most patients (74.0%) reported that they were in good, very good, or excellent health. Overall, 28.7% of respondents said that they were not at all comfortable with stopping low-value colorectal cancer screening and 49.3% said that decisions about when to stop screening should never be based on age. Almost a third (31.75%) thought it was not at all reasonable to use life expectancy calculators in screening decisions, and 24.3% thought using calculators for colorectal cancer risk was not at all reasonable. More trust in the physician (odds ratio [OR], 1.19; 95% CI, 1.07 to 1.32), higher perceived health status (OR, 1.41; 95% CI, 1.23 to 1.61), and more barriers to screening (OR, 1.20; 95% CI, 0.73 to 0.89) were associated with greater comfort with stopping screening, while greater perceived effectiveness of screening (OR, 0.86; 95% CI, 0.80 to 0.94) and greater perceived threat of colorectal cancer (OR, 0.81; 95% CI, 0.73 to 0.89) were associated with less comfort.

The researchers noted that their study included veterans from a single region, limiting the potential generalizability of their results, and that all respondents had previously had colonoscopy, among other limitations. However, they concluded that according to their findings, many veterans do not want to stop low-value screening for colorectal cancer and do not trust physicians' ability to predict risk and life expectancy, even when calculators are used. Given this, patients may resist attempts to individually tailor screening, and more research into effective communication on this topic is needed, the authors stated.

An accompanying invited commentary noted that the study assessed health literacy rather than health numeracy and that questions about ceasing low-value screening in the context of adverse events and other complicating factors were not included in the survey. The commentary authors also felt that the study authors sometimes presented their data “with a ‘glass half-empty’ perspective,” noting that while 40.6% of respondents said they had at least some degree of comfort with stopping screening based on their physician's recommendation, the study focused on the 28.7% who said they would not be at all likely to follow this recommendation.

The commentary authors said that there is a role for deimplementation of routine screening when potential harms outweigh potential benefits, that the current study shows the importance of increased education about health numeracy and risk calculators, and that efforts to correct underuse of screening should concurrently address potential harms from overuse. “By involving patients and other relevant stakeholders in the development and dissemination of these tools, acceptable and sustainable precision colorectal cancer screening that incorporates risk prediction models may be within reach,” they wrote.