Presentation (CTI)

OBJECTIVES: Care of older-adults is often characterized by complex chronic conditions and polypharmacy. Therapeutic duplication(TD), the prescription of multiple medications from the same class, contributes to polypharmacy and increases the risk of adverse drug events. This research aims to assess the rate of TD and predictors of TD among older-adults within the National Social Health in Aging Project(NSHAP) study.
METHODS: Older-adults(≥65 years) who completed the medication and health status portions of the 2015 NSHAP survey were included. Medications were linked to ATC codes with TD considered at the 4-digit level (pharmacologic subgroup). Utilizing Andersen’s behavioral model, six predisposing, five enabling, and nine need factors contributing to TD were hypothesized. Bivariate associations were assessed and a logistic model run with hypothesized variables included a priori. Prevalence ratios were estimated via modified Poisson regression with a robust variance estimator.
RESULTS: Among 1618 older-adults, 36.4% had TD. Top duplicated medication classes were non-insulin glucose lowering drugs(A10B;7.7% of sample), other analgesics/ antipyretics(N02B;7.4%), NSAIDs(M01A;6.2%), antithrombotic agents(B01A;5.6%), and lipid-modifying agents(C10A;4.4%). In bivariate analyses, age(p=0.025), gender(p<0.001), not-working vs. working(p=0.002), retired vs. working(p=0.002), difficulty driving(p=0.015), self-reported physical health(p<0.001), self-reported mental health(p=0.005), having pain(p<0.001), pain-level(p<0.001), heart problems(p<0.001), diabetes(p<0.001), and emphysema/COPD(p<0.001) were associated with TD. In the logistic model, older age(p=0.027), male gender(p=0.020), retired vs. working(p=0.045) worse self-reported physical health(p<0.001), higher pain levels(p=0.020), heart problems(p=0.007), diabetes(p<0.001), and emphysema/COPD(p=0.002) were significant predictors of TD. In the Poisson analysis, the prevalence ratios of age(1.01 CI:1.00,1.02), female gender(0.843 CI: 0.730,0.972), other race vs. non-hispanic white(1.417 CI:1.042,1.927), physical health(0.856 CI:0.797,0.918), pain-level(1.095 CI:1.014,1.184), heart problems(1.211 CI:1.056,1.387), diabetes(1.584 CI:1.374,1.825), and emphysema/COPD(1.262 CI:1.082,1.472) were significant.
CONCLUSIONS: TD was common among older-adults. TD was more common in older patients, men, retirees, patients reporting worse health, and patients with chronic conditions. The prevalence of TD underscores the need for better medication review to prevent potentially dangerous polypharmacy.