Patient and Physician Factors Associated With Adherence to Diabetes Medications

Abstract

The purpose of this study was to examine the influence of patient and physician psychosocial, sociodemographic, and disease-related factors on diabetes medication adherence. These factors were also examined as effect modifiers of the association between quality of the patient-physician relationship and medication adherence. Data were collected from 41 Geisinger Clinic primary care physicians and 608 of their patients with type 2 diabetes. Adherence to oral hypoglycemic medications was calculated using a medication possession ratio based on physician orders in electronic health records (MPR(EHR)). MPR(EHR) was defined as the proportion of total time in the 2 years prior to study enrollment that the patient was in possession of oral hypoglycemic medications. Linear regression was used to examine the influence of patient- and physician-level factors on adherence. Effect modification of the patient-physician relationship-adherence association was evaluated by adding the main effects of the individual-level factors and their cross-products to the models. In adjusted analyses, satisfaction with the physician's patient education skills, patient beliefs about the need for their medications, and lower diabetes-related knowledge were associated with better adherence to oral hypoglycemic medications. Shorter duration of time with diabetes and taking only oral hypoglycemic medications were also associated with better adherence. Finally, the association between shared decision making and medication adherence was significantly modified by patients' level of social support. This study identified several patient-, physician-, and disease-related factors that should be targeted to maximize the potential for developing tailored adherence-enhancing interventions within the context of a collaborative patient-physician relationship.