Medication Adherence in Patients with Glaucoma and Disability

Importance: People with disabilities tend to have lower medication adherence. Glaucoma medication adherence has been scantly studied for people with disability. Objective: To determine whether disability leads to reduced glaucoma medication adherence and whether this decrease varies by type of disability. Design, Setting, and Participants: This population-based case-control study enrolled individuals with glaucoma and without disability, who were followed up until they received disability certification. All patients in Taiwan with confirmed glaucoma in 1 or both eyes were identified using National Health Insurance claims data. All patients with glaucoma who required glaucoma medication adherence (confirmed glaucoma, suspected glaucoma, and patients with ocular hypertension) and had newly obtained disability status after December 31, 2013, were identified and matched to counterparts without disability based on age and sex. The study period was January 1, 1997, to December 31, 2017. Data were analyzed from May 2021 to August 2021. Exposures: All patients were followed up until they obtained confirmed disability status, which was identified using the National Disability Registry in Taiwan. Main Outcomes and Measures: Secondary adherence was measured using frequencies of glaucoma medication refills and outpatient visits at 1-year and 2-year intervals. Results: A total of 46468 patients with glaucoma (23234 with disability and 23234 without disability; 24508 men [52.7%]; 21960 women [47.3%] mean [SD] age, 72.5 [14.3] years) were included in the study. Overall, the frequency of glaucoma outpatient visits was higher in people with disabilities than those without disabilities both before the index dates (difference, 0.64 [95% CI, 0.57-0.72]; P <.001) and after the index dates (difference, 0.34 [95% CI, 0.27-0.41]; P <.001) when using 1-year intervals. However, when stratified by the type of disability, having limb disability, being in a vegetative state, and having dementia were associated with fewer outpatient visits and lower medication adherence (at a maximum of 17.60 [95% CI, 8.90-26.30] percentage points lower; P <.001) compared with people without disability. Adjusted regression results revealed that people with visual disability had a mean of 2.50 (95% CI, 2.34-2.67) times more glaucoma outpatient visits than their matches who were disability free (P <.001). Conclusions and Relevance: Certain types of disability can reduce glaucoma medication adherence by up to 17.60%. Policies targeting medication adherence should consider these disability types.