Background & Aims
Nonadherence to medication therapy is a common problem among patients with chronic diseases, including chronic pain, with a reported prevalence ranging from 8% to 62%. Nonadherence to medication not only leads to failure of treatment but also results in increased healthcare costs due to the waste of medications. This study aimed to determine the prevalence of nonadherence to pain medications and its impacts among patients who visit the outpatient pain clinic at Siriraj Hospital, the tertiary care center in Bangkok.
Methods
A cross-sectional study was conducted from September to December 2021, involving 150 chronic pain patients who visited the pain clinic at Siriraj Hospital. A self-administered questionnaire was used to collect demographic and treatment-related information. Medication adherence was evaluated using the Thai version of the Morisky Medication Adherence Scale-8 (MMAS-8) questionnaire and pill count. The Brief Pain Inventory was used to assess the intensity of pain and its impact on daily life. Data analysis was performed using descriptive statistics and the association between medication adherence and treatment outcomes was assessed using logistic regression analysis. The total cost of the unused medication was calculated based on the market value of each unused medication.
Results
The overall prevalence of nonadherence to pain medications in this study was 53.1%; 25.3% by MMSA scoring and 38% by pill count ( 30.7% underuse and 7.3% overuse). The common reasons for medication underuse were an improvement in symptoms (58%), experiencing side effects (30.1%), and concerns about side effects (15.1%). The common reasons for medication overuse were inadequate pain control (87.8%) and use to prevent pain (17%). The prevalence of nonadherence is high among participants receiving strong opioids (40.5%), anticonvulsants (36.2%), and NSAIDs (26.9%). However, there is no significant association between sociodemographic data, diagnosis, number of prescribed analgesics, and drug compliance. The non-adherence was associated with less pain reduction after treatment, greater impact of pain on normal work, and decreased enjoyment of life (p-value < 0.05). The total cost of leftover medication during this observation period was 76,981.5 Thai Baht.
Conclusions
This study reveals that the prevalence of nonadherence to analgesic medications among patients with chronic pain is high. Additionally, nonadherence to analgesic medications is associated with negative impacts on clinical outcomes and function. Lastly, nonadherence results in increased healthcare costs, and societal and environmental impacts due to the cost of unused drugs and improper drug disposal.
References
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Presenting Author
Nantthasorn Zinbonyahgoon
Poster Authors
Topics
- Access to Care