The Most Common Barriers to Glaucoma Medication Adherence

Abstract

Purpose To both evaluate the frequency of eleven commonly cited barriers to optimal glaucoma medication adherence among glaucoma patients and identify barriers contributing to poor adherence. Design Prospective, cross-sectional survey. Participants 190 adults with glaucoma taking ≥1 glaucoma medication who received care in glaucoma clinics in Ann Arbor, MI and Baltimore, MD. Methods Participants completed a survey on demographic and disease characteristics, barriers to optimal glaucoma medication adherence, interest in an eye drop aid, and self-reported adherence (measured by the Morisky Adherence Scale). Descriptive statistics and logistic regression analyses were performed. Main Outcome Measures Frequency and number of barriers to adherence among both adherent and non-adherent patients. Odds ratios with 95% confidence intervals identifying barriers associated with poor adherence. Results 27% of the sample reported poor adherence. 61% of all participants cited multiple barriers and 10% cited a single barrier as impediments to optimal adherence. 29% of subjects cited no barriers, though only 13% of patients who cited no barriers were non-adherent. Among non-adherent patients, ≥31% cited each of the eleven barriers as important. Logistic regression analysis, adjusted for age, revealed that the following barriers were associated with higher odds of non-adherence: decreased self-efficacy, OR = 4.7 [95% CI 2.2–9.7, p= < 0.0001]; difficulty instilling drops, OR = 2.3 [95% CI 1.1–4.9, p= 0.03]; forgetfulness, OR = 5.6 [95% CI 2.6–12.1, p= < 0.0001]; and difficulties with the medication schedule, OR = 2.9 [1.4–6.0, p= 0.006]. For each additional barrier cited as important, there was a 10% increased odds of being non-adherent, OR = 1.1 [95% CI 1.0–1.2, p= 0.01]. Conclusion Each of the eleven barriers was important to at least 30% of surveyed patients with poor adherence, with the majority identifying multiple barriers to adherence. Low self-efficacy, forgetfulness, and difficulty with drop administration and the medication schedule were all barriers associated with poor adherence. Interventions to improve medication adherence must address each patient’s unique set of barriers.