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

Abstract

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.