Prescriber Continuity and Medication Adherence for Complex Patients

Background: Medication adherence is a critical aspect of managing cardiometabolic conditions, including diabetes, hypertension, dyslipidemia, and heart failure. Patients who have multiple cardiometabolic conditions and multiple prescribers may be at increased risk for nonadherence. Objective: The purpose of this study was to examine the relationship between number of prescribers, number of conditions, and refill adherence to oral medications to treat cardiometabolic conditions. Methods: In this retrospective cohort study, 7933 veterans were identified with 1 to 4 cardiometabolic conditions. Refill adherence to oral medications for diabetes, hypertension, and dyslipidemia was measured using an administrative claims–based continuous multiple-interval gap (CMG) that estimates the percentage of days a patient did not possess medication. We dichotomized refill adherence for each condition as a CMG ≤20% for each year of analysis. Condition-specific logistic regression models estimated the relationship between refill adherence and number of cardiometabolic conditions and number of prescribers, controlling for demographic characteristics, other comorbidities, and a count of cardiometabolic drug classes used. Results: Compared with patients with 1 prescriber, antihypertensive refill adherence was lower in patients seeing ≥4 prescribers (odds ratio [OR] = 0.69; 95% CI = 0.59-0.80), but the number of cardiometabolic conditions was not a significant predictor. Antidyslipidemia refill adherence was lower in patients seeing 3 prescribers (OR = 0.80; 95% CI = 0.70-0.92) or ≥4 prescribers (OR = 0.77; 95% CI = 0.64-0.91). Conversely, antidyslipidemia refill adherence improved with the number of cardiometabolic conditions, but differences were only statistically significant for ≥3 conditions (OR = 1.31; 95% CI = 1.09-1.57). In multivariate regression models, the number of conditions and number of prescribers were not significant predictors of refill adherence in the group of patients with diabetes. Conclusions: Effective management of care and medication regimens for complex patients remains an unresolved challenge, but these results suggest that medication refill adherence might be improved by minimizing the number of prescribers involved in a patient’s care, at least for hypertension and dyslipidemia.