Medication Adherence in Patients with Glaucoma After Cancer Diagnosis

Abstract Purpose To determine the association between cancer diagnosis on medication adherence in patients with glaucoma. Design Cohort study Methods Setting : Population-based. Study Population : All patients with confirmed glaucoma in one or both eyes. All patients were aged 20 years or older. Patients who developed cancer within one year of a confirmed glaucoma diagnosis or who were dead within one year after a confirmed cancer diagnosis were excluded. Intervention or Observation Procedure(s) : Individuals without cancer but with a confirmed glaucoma diagnosis were followed until they received a confirmed cancer diagnosis. They were then matched with a group of patients with confirmed glaucoma who did not develop cancer during the study period. Main Outcome Measure(s) : Secondary adherence measured using medication possession ratio (MPR) at 1-year, 2-year, and 2-year-average intervals. Results For both patients with cancer and their matches, MPR was the highest when measured at 1-year intervals. MPR was 0.379 (95% CI: 0.370–0.388) for the cancer group and 0.313 (95% CI: 0.308–0.319) for the cancer-free group. MPR measured using 1-year intervals decreased by 17.4% (p Conclusions Cancer diagnosis leads to lower medication adherence in patients with glaucoma. To improve medication adherence in patients with glaucoma who also have cancer, policies should directly target the burden associated with having cancer that tends to create barriers for medication refills, rather than targeting risk factors that are also applicable to patients with glaucoma but without cancer.