Adherence, Burden, and Morbidity in Adults with Chronic Diseases in the Dominican Republic: A Cross-sectional Study in a Tertiary-level Hospital (A-CaMo II)

Introduction: Pharmacological adherence is a key factor in managing chronic non-communicable diseases (NCDs), so its efficacy concerning new therapies emerges as an essential consideration. Despite efforts, adherence rates vary widely, highlighting the complexity of the problem. Non-adherence affects treatment effectiveness and increases patient burden and medical costs. Understanding the interplay between burden, morbidity, and adherence is crucial for adapting health strategies. Objective: This study aims to measure pharmacological adherence, burden, and morbidity among patients with chronic diseases in the Dominican Republic, emphasizing the interplay between these dimensions. Methods: Data were collected using a cross-sectional design at the Centro Médico de Diabetes, Obesidad y Especialidades (CEMDOE) in Santo Domingo during August 2023. Patient interviews were conducted using standardized tools, including the Medication Adherence Reasons Scale (MAR-Scale) and the Disease Burden Morbidity Assessment (DBMA). Nonprobability convenience sampling yielded a sample of 384 patients who met the inclusion criteria. Significant statistical analysis included an ordinal regression analysis correlating medication adherence with disease burden. Results: Among the patients studied, the ordinal regression analysis unveiled a significant correlation (p = 0.001) between nonadherence and disease burden, indicating a 0.29 ± 0.09 unit increase in burden for every one-point decrease in adherence score. Patients with private health insurance and higher education levels exhibited more excellent adherence rates (65.97% and 63.89%, respectively), with a substantial portion also reporting a burden score ≥ 5 (70.07% and 70.42%, respectively). Moreover, the study population experienced a significant burden of multimorbidity (88.8%), with hypertension displaying the lowest burden (1.63 ± 1.13) despite its prevalence (76.76%). Conclusion: Despite the limitations, common reasons for non-adherence were identified, and significant disease burdens were observed, particularly in osteoarthritis, cancer, and rheumatoid arthritis. Notably, a positive association was found between adherence and disease burden, underlining the importance of adherence in chronic disease management. Health disparities affecting access to medication and patient education were observed, highlighting the need for further research and intervention. The combined use of a scale that integrates both the DBMA and the MAR-Scale, in which adherence, burden, and morbidity are investigated simultaneously for each disease, would allow for a more comprehensive approach to all three characteristics regardless of which disease is included in the scales separately.