Purpose: (i) To evaluate the medication adherence rate of glaucoma patients in Singapore. (ii) To evaluate patients' quality of life status. (iii) To explore the factors related to patients' nonadherence to medication.
Patients and methods: A cross-sectional, prospective study, using interviewer-administered survey questionnaires. A total of 314 patients were interviewed altogether, of which 175 (55.7%) were male and 139 (44.3%) were female. (i) Patients' medication adherence was assessed using the Reported Adherence to Medication scale. (ii) Patients' beliefs about glaucoma and treatment were evaluated using the Brief Illness Perception Questionnaire and the Beliefs about Medicine-Specific Questionnaire. (iii) Patients' quality of life was evaluated using Glaucoma Symptom Scale and The Glaucoma Quality of Life-15 questionnaire.
Results: Sixty-two (19.7%) patients reported themselves to be adherent to their medication. Male patients (P=0.044) and smokers (P=0.002) were more likely to be nonadherent to their medication regimen. Nonadherent patients were more likely to have (i) more concerns about their glaucoma medications (P=0.000); (ii) less belief in the effects of their medications (P=0.026); (iii) a lower quality of life (higher score of GQOL-15, P=0.014); (iv) less symptoms from their glaucoma (lower score of Glaucoma Symptom Scale, P=0.026); and (v) more effect on their lives from glaucoma (P=0.01).
Conclusions: The full-adherence rate is low among glaucoma patients. Having less belief in the need for and more concerns about their medication are the 2 factors associated with nonadherence. In the future, effective strategies should be explored to improve patients' beliefs. Nonadherence has an association with decreased quality of life. Strategies to improve adherence will need to deal with these areas.