The Most Common Barriers to Glaucoma Medication Adherence: A Cross-Sectional Survey

Purpose To evaluate the frequency of 11 commonly cited barriers to optimal glaucoma medication adherence among glaucoma patients and to identify barriers contributing to poor adherence. Design Prospective, cross-sectional survey. Participants One hundred ninety adults with glaucoma taking 1 or more glaucoma medication who received care in glaucoma clinics in Ann Arbor, Michigan, and Baltimore, Maryland. 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 nonadherent patients. Odds ratios (ORs) with 95% confidence intervals (CIs) identifying barriers associated with poor adherence. Results Twenty-seven percent of the sample reported poor adherence. Sixty-one percent of all participants cited multiple barriers and 10% cited a single barrier as impediments to optimal adherence. Twenty-nine percent of subjects cited no barriers, although only 13% of patients who cited no barriers were nonadherent. Among nonadherent patients, 31% or more cited each of the 11 barriers as important. Logistic regression analysis, adjusted for age, revealed that the following barriers were associated with higher odds of nonadherence: 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; 95% CI, 1.4-6.0; P = 0.006). For each additional barrier cited as important, there was a 10% increased odds of being nonadherent (OR, 1.1; 95% CI, 1.0-1.2; P = 0.01). Conclusions Each of the 11 barriers was important to at least 30% of surveyed patients with poor adherence, with most identifying multiple barriers to adherence. Low self-efficacy, forgetfulness, and difficulty with drop administration and the medication schedule were barriers associated with poor adherence. Interventions to improve medication adherence must address each patient's unique set of barriers.