Evaluating adherence to concomitant diabetes, hypertension, and hyperlipidemia treatments and intermediate outcomes among elderly patients using marginal structural modeling

Abstract

Medication adherence to concomitant oral antidiabetics, statins, and renin-angiotensin system (RAS) antagonists (triple therapy) is vital to manage glycated hemoglobin (A1C) and low-density lipoprotein cholesterol (LDL-C) control among patients with comorbid diabetes, hyperlipidemia, and hypertension. The objective of the current study was to evaluate the association between adherence to concomitant triple therapy and A1C as well as LDL-C outcomes, among elderly patients using marginal structural modeling. A retrospective cohort study with patients on concurrent triple therapy was conducted using a Texas Medicare Advantage database from January 2016 until December 2019. Medication adherence to concurrent triple therapy was measured every 6 months using proportion of days covered (PDC) to determine the different adherence groups. A1C and LDL-C control was also measured every 6 months. A marginal structural model controlling for baseline covariates and time-varying confounders affected by prior adherence was conducted to evaluate the association between adherence to concomitant triple therapy and A1C and LDL-C control. The LDL-C cohort was comprised of 4803 patients and the A1C cohort was comprised of 5314 patients on triple therapy. Patients who were adherent to triple therapy [odds ratio(OR):1.84, 95% confidence interval (CI): 1.62-2.10] and adherent to double therapy (OR:1.42, 95% CI: 1.24-1.62) were more likely to have their LDL-C in control as compared to patient's adherent to monotherapy/none. Similarly, patients who were adherent to triple therapy (OR:1.30, 95% CI: 1.11-1.52) and adherent to double therapy (OR:1.32, 95% CI: 1.12-1.55) were more likely to have their A1C in control as compared to patient's adherent to monotherapy/none. The current study demonstrated the beneficial effects of adherence to concurrent oral antidiabetics, statins, and RAS antagonists among elderly patients in a real-world setting.