Treatment Burden and Medication Adherence Among Adults With Multimorbidity: A Cross-Sectional Study

Background: Treatment burden may represent an important barrier to medication adherence among adults with multimorbidity.Unlike medication burden alone, treatment burden encompasses the broader workload associated with managing multiple chronic conditions, including medications, appointments, monitoring, lifestyle recommendations, and care coordination.This study evaluated the association between treatment burden and medication adherence among adults with multimorbidity receiving outpatient care in Dammam, Saudi Arabia.Methods: This cross-sectional study included adults aged 18 years or older with two or more physiciandiagnosed chronic conditions who were taking at least one prescribed long-term medication.Treatment burden was assessed using the Multimorbidity Treatment Burden Questionnaire (MTBQ), and medication adherence was assessed using the 12-item Adherence to Refills and Medications Scale (ARMS).Multivariable linear regression was used to evaluate the association between treatment burden and medication adherence, adjusting for age, sex, educational attainment, household income, number of chronic conditions, number of medications, medication dosing frequency, and number of prescribing physicians.Results: A total of 512 participants were included.The mean (standard deviation (SD)) age was 61.4 (12.7) years, and 278 participants (54.3%) were women.The median number of chronic conditions was 4 (interquartile range (IQR): 3-5), and the median number of medications was 6 (IQR: 4-8).The mean (SD) MTBQ score was 24.8 (16.3), and the mean (SD) ARMS score was 18.7 (4.2).Each 10-point increase in MTBQ score was associated with a 0.61-point increase in ARMS score (95% confidence interval (CI): 0.34-0.88;P < 0.001) after multivariable adjustment.Each additional medication was associated with a 0.17-point increase in ARMS score (95% CI: 0.04-0.30;P = 0.01), while having three or more prescribing physicians was associated with a 0.64-point increase (95% CI: 0.17-1.11;P = 0.008).Mean ARMS scores increased progressively across treatment-burden categories, from 16.8 (3.2) among participants with little or no treatment burden to 22.0 (4.8) among those with high treatment burden (P for trend < 0.001).Conclusion: Greater treatment burden was associated with poorer medication adherence among adults with multimorbidity receiving outpatient care in Dammam, Saudi Arabia, independent of medication burden and other patient characteristics.These findings suggest that medication adherence may be influenced by the broader workload of managing multimorbidity in addition to the number of medications prescribed.Prospective studies are needed to determine whether reducing treatment burden can improve medication adherence and clinical outcomes.