Objective: Nonadherence to medication is a frequent problem in geriatric patients. However, little is known regarding its impact on outpatients in tertiary care hospitals, who often have multiple comorbidities and complex of medication regimens. The objective of the present study was thus to evaluate the association between medication nonadherence and health outcomes.
Materials and Methods: This was a cross-sectional study of geriatric patients who attended an outpatient clinic of a tertiary care hospital in Thailand between May 2019 and May 2020. Baseline characteristics and clinical outcomes, including falls, unplanned admission, and quality of life (using the World Health Organization quality of life-old module [WHOQOL-Old]) were collected. The 8-item Morisky Medication Adherence Scale (MMAS-8) was used to assess medication adherence.
Results: Of the 250 patients enrolled, 36.4% were found to practice poor medication adherence. Number of falls and unplanned hospitalizations over the past 12 months were positively associated with poor adherence (adjusted odds ratio [AOR] of 3.02 and 1.74, respectively). WHOQOL-Old score was negatively associated with poor adherence (AOR 0.93).
Conclusion: Nonadherence was common in these patients and significantly associated with a greater number of falls, lower quality of life, and increased hospitalization. This issue should be addressed in clinical practice to reduce unfavorable health outcomes.

Keywords: Chronic disease; Elderly; Fall; Hospitalization, Quality of life