Determinants of Self-Reported Barriers to Glaucoma Medicine Administration and Adherence: A Multisite Study

Background: Many factors influence glaucoma medication adherence. A better understanding of the relationships between health literacy, depressive symptoms, and patient-reported problems in using glaucoma medications may reveal opportunities for intervention that could improve patients' clinical outcomes. Objective: To examine the relationship between patient characteristics (demographics, health literacy, and depressive symptoms) and patient-reported problems in using glaucoma medications and to assess factors related to patients' self-reported adherence to glaucoma medications. Methods: Patients diagnosed with primary open-angle glaucoma (n = 228) currently taking intraocular pressure lowering medications were recruited at 6 ophthalmology clinics. Patients were interviewed to identify problems using glaucoma medications, and self-reported medication adherence was determined using a Visual Analog Scale. Questionnaires were administered to assess health literacy, depressive symptoms, outcome expectations, and medication self-efficacy. Results: Younger patients (P = 0.03), patients with depressive symptoms (P = 0.02), and patients who reported more medication problems (P = 0.005) were significantly less adherent to their glaucoma medications. Patients with higher glaucoma medication self-efficacy adherence scores (P = 0.003) and higher outcome expectations (P = 0.03) were significantly more adherent. Conclusions: Providers should consider using tools to screen glaucoma patients for depressive symptoms and for problems in using medications to identify patients who are at higher risk of nonadherence to treatment and who might benefit from follow-up with primary care providers.