Medication nonadherence in elderly patients in a Thai geriatric clinic

Background: Medication nonadherence is common in elderly patients and is a major cause of morbidity. However, it is not well-described in the literature and to our knowledge has never been studied in Thais.

Objective: To investigate the extent, causes, and contributing factors of medication nonadherence in older patients in a geriatric clinic.

Material and Methods: We conducted a cross-sectional study at Siriraj Hospital, a university teaching hospital in Bangkok. We assessed baseline demographic data, comorbid diseases, Thai Mental State Examination (TMSE), functional status (basic and basic activities of daily living), type and number of medications used, and medication adherence.

Results: There were 153 participants in this study. Medication nonadherence, in the administration of prescribed drugs only, was found in 34% of the participants. Nonadherence to administration of prescribed drugs and to the advice regarding over-the-counter drugs was 42.5%. Nonadherence to the administration of prescribed drugs and to the advice regarding over-the-counter drugs, and herbal and dietary supplements was 54.9%. Three most common causes of medication nonadherence were misunderstanding or lack of the knowledge (25.6%), the development of adverse drug events (18.9%), and because of a suggestion by a friend or family member (16.2%).

Conclusion: Medication nonadherence is common in elderly Thais attending geriatric clinics. We recommend clinicians be aware of this problem and develop a system to improve medication adherence. The clarification of reasons for prescribing is crucial. We recommend emphasis on educating patients, family members, and the public about the risk of nonadherence and of using nonprescribed medications.