Polypharmacy risk among five-year cancer survivors.

Abstract

11565 Background: Cancer survivors are increasing in the United States. Survivors often face cancer sequelae and side effects from treatment, which can arise during treatment or even months or years later. Survivors may therefore experience greater medication burden than the general population, increasing concerns for polypharmacy and risk of drug interactions and non-adherence. The objective of this study is to characterize prevalence of polypharmacy by cancer history in a nationally-representative sample of U.S. adults. Methods: Using National Health and Nutrition Examination Survey (NHANES) data from 2003-2014, we identified 32,330 individuals 20 years or older, 1,672 of whom had been diagnosed with cancer (excluding non-melanoma skin) at least five years before the survey. The association between cancer history and polypharmacy (5+ medications) was examined using Poisson regression models to calculate multivariable risk ratio (RRs) and 95% confidence intervals (CIs), adjusted for education, ethnicity, marital status, and age at survey. Results: Among five-year cancer survivors, 35% had a diagnosis within 5-9 years of the survey year, 26% within 10-14 years, 13% within 15-19 years, and 26% had a diagnosis 20 or more years before the survey year. Breast cancer was the most common type of cancer (23%), followed by cervical cancer (18%), prostate cancer (12%), and colon cancer (7%). Prevalence of polypharmacy was higher in cancer survivors (33.6%; 95% CI: 30.7-36.6%) than in those with no cancer history (13.0%, 95% CI: 12.4-13.7%) (RR: 1.32, 95% CI: 1.20, 1.45). Polypharmacy prevalence differed by age group (4.83% in 20-39 year olds; 40.37% in 40-64 year olds; 54.8% in 65 years and older), and within each age group, risk of polypharmacy was higher in cancer survivors than in those with no cancer history, with the most pronounced difference in cancer survivors 20-39 years old (RR: 2.93, 95% CI: 1.69-5.09), followed by 40-64 year olds (RR: 1.52, 95% CI 1.27-1.83) and those 65 years and older (RR: 1.17, 95% CI: 1.07-1.29). Conclusions: Cancer survivors are more likely to experience polypharmacy burden than those with no cancer history. Findings from this study can increase awareness about the unique challenges cancer survivors face and encourage medication reconciliation services.