Disparities in all-cause mortality with potentially inappropriate medication use: Analysis of the Reasons for Geographic and Racial Differences in Stroke study.

objectivesHealth disparities across different socioeconomic subgroups have been reported in previous studies. Mortality with potentially inappropriate medication (PIM) use may be subject to similar disparities. We aimed to assess the association between PIM use and all-cause mortality and the effect of disparity parameters (sex, race, income, education, and location of residence) on this relationship.

methodsThis longitudinal cohort study included 26,399 U.S. adults aged 45 years and older from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, of which 13,475 participants were aged 65 years and older (recruited 2003-2007). PIM use and drug-drug interactions (DDIs) were identified through the 2015 Beers Criteria and a clinically significant DDIs list by the American Family Physicians, respectively. Cox regression was used to assess disparities in mortality with PIM use, iteratively adjusting for disparity parameters and other covariates. The full models included interaction terms between PIM use and other covariates. A similar method was used for the analyses of disparities in mortality with DDIs.

resultsApproximately 87% of older adults used at least 1 drug listed in the Beers Criteria, and 3.8% of all participants used 2 or more drugs with DDIs. In the adjusted analysis, an increased risk of mortality was observed among whites with PIM use (hazard ratio [HR] = 1.27 [95% CI 1.10-1.47]). The higher mortality rate was observed among blacks without PIM use (1.34 [1.09-1.65]). Lower income and education were independent predictors for higher mortality.

conclusionRacial differences in all-cause mortality with PIM use were observed. Further research is needed to better understand the contributing factors of such disparities to develop appropriate interventions.