Health Systems and Self-Reported Medication Adherence in Patients with Hypertension: A cross-sectional comparison of Jamaica and Colombia.

Robust health care systems can support medication adherence as a strategy to improve blood pressure control in Latin America and the Caribbean. The Caribbean and South American Team Based Strategies to Control Hypertension (CATCH) study, conducted in Jamaica and Colombia, allowed us to examine how differing health systems (Jamaica - manual, paper-based, government run vs Colombia - electronic systems utilizing government contracted providers) influenced self-reported antihypertensive medication adherence among hypertensive patients. A total of 576 hypertensive patients from 14 primary care clinics completed telephone interviews between August 2021 and February 2022 during the COVID-19 pandemic. Self-reported medication adherence was measured using the IMPACTS-MAS questionnaire and patients categorized as having high (6), medium (5-5.5) or low (<5) adherence based on score. Country was used as a proxy for health systems in multivariable logistic regression models with medium/low adherence as the primary outcome. Jamaican patients were more likely to report medium/low adherence (49.3% vs 11.8% p <0.001). In Colombia, younger (< 60 years) and never married patients reported more medium/low adherence. Jamaican patients experienced longer wait times for services but were more likely to discuss medication changes with the pharmacist while Colombian patients had more discussions with their doctor. Jamaicans had a higher odds of medium/low adherence compared to Colombians (OR: 6.78 (95% CI: 3.91, 11.75) after adjusting for sociodemographic factors and health care experiences. Further exploration of health system issues that may explain these differences can inform strategies to improve medication adherence in the region.