Nonadherence to Cancer Screening Associated With Mortality Unrelated to Cancer

A study of more than 60,000 individuals indicated that those who do not adhere to cancer screening guidelines are at an increased risk of all-cause mortality unrelated to cancer malignancies. This finding came from a secondary analysis of the Prostate, Lung, Colorectal and Ovarian Cancer Screening (PLCO) trial and was published in JAMA Internal Medicine.

Researchers randomized patients from 10 U.S. screening centers between November 8, 1993, and July 2, 2001. Patients were originally followed for 13 years or through December 31, 2009, but participants re-consented to further follow-up starting May 18, 2011, and were observed through December 31, 2012. A total of 64,567 patients (29,537 women and 35,030 men; mean age = 62.3 years) were included in the analysis.

At baseline, participants completed a self-administered questionnaire. Individuals were classified as those receiving all sex-specified PLCO cancer screening tests at baseline (adherent; n=55,065; 85.3%), those receiving some baseline tests (partially adherent; n=2,548; 3.9%), and those receiving no baseline tests (nonadherent; n=6,954; 10.8%).

At 15 years of follow-up, there were 7,966 deaths, excluding those from the cancer, among patients who were adherent, 449 deaths among those who were partially adherent, and 1,395 deaths among those who were nonadherent.

Within 10 years of follow-up, the hazard ratio (HR) of mortality, excluding deaths from cancers and controlling only for age, sex, and race/ethnicity (model 1), was 1.73 (95% CI, 1.60-1.89) for nonadherent individuals compared with adherent participants. The HR of mortality was 1.36 (95% CI, 1.19-1.54) for partially adherent individuals compared with fully adherent participants.

After adjusting for medical risk factors for mortality and behavioral-related factors such as obesity and smoking (model 2), the HR decreased to 1.46 (95% CI, 1.34-1.59) for nonadherent patients compared with adherent participants. Those who did not undergo screenings were 46% more likely to die compared with 26% of those who skipped some screenings.

“It was not a direct effect of missing the cancer screening that led to the increased mortality in the noncompliers,” Paul Pinsky, PhD, of the National Cancer Institute, told Reuters. “Rather, we believe that noncompliance with the screening was a marker of a wider health behavioral profile of general noncompliance with or nonadherence to medical tests and treatments. Non-compliance with medical procedures has also been linked, in this and other studies, to other unhealthy lifestyle factors such as obesity and smoking, and to lower education.”

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Source: JAMA Internal Medicine