Predictors of Mortality in the Older Population: The Role of Polypharmacy and Other Medication and Chronic Disease-Related Factors.

Abstract

Polypharmacy has been associated with increased mortality but the contribution of different medication-related factors to this is unknown. The aim of this study was to identify demographic and medication-related predictors of mortality in the older population. Given the intrinsic link between polypharmacy and multimorbidity, the secondary aim was to examine if the medicines or underlying diseases predicted mortality. Patients aged ≥ 65years from an outpatient multimorbidity clinic were included. Medication-related factors included the medicines count, high-risk medicines, inappropriate medicines duplication, and potential drug-drug and drug-disease interactions. Logistic regression was used to identify mortality predictors within a year of clinic discharge from the outpatient clinic. Patients attend the clinic until medications and comorbidity management have been optimised, at which point they are discharged from the clinic, and their General Practitioner provides ongoing care. A total of 584 patients were included (median age 80.0years) and 9.9% (n = 58) died within a year of discharge. Demographics, namely age (adjusted odds ratio [aOR] 1.05; 95% CI 1.01-1.09; p = 0.018) and being male (aOR 5.10; 95% CI 2.63-9.88; p < 0.001); chronic disease, namely heart failure (aOR 3.36; 95% CI 1.78-6.35; p < 0.001); and medication-related factors, namely the number of sedative and anticholinergic medicines (aOR 1.66; 95% CI 1.19-2.33; p = 0.003) predicted mortality in the study population. Whilst polypharmacy has been defined using the number of medicines in the literature, a combination of demographics, chronic disease and medications predicted mortality in our study. This provides guidance for the development of future tools and guidelines regarding the inclusion of key factors for identifying high-risk patients at risk of adverse health outcomes such as mortality.