Adherence, Persistence, and Blood Pressure Control in Hypertensive Patients: A Cross-Sectional Study in Mureș County, Romania

Background: Nonadherence to antihypertensive therapy affects nearly half of treated patients worldwide, and persistence often falls below 60% within the first year, contributing substantially to uncontrolled blood pressure and cardiovascular morbidity. Adherence and persistence to antihypertensive therapy among primary care patients in Mureș County, Romania, were assessed using validated measures, and modifiable risk factors for targeted interventions were identified. Methods: A cross-sectional study of 399 hypertensive adults (≥18 years) receiving treatment for ≥1 year across primary care clinics in Mureș County, Romania, was performed. Adherence was evaluated using the Romanian-validated Hill–Bone Compliance to High Blood Pressure Therapy Scale (HBCTS) and confirmed by mean arterial pressure (MAP) < 100 mmHg. Receiver operating characteristic (ROC) curve analysis was employed to determine the optimal HBCTS cutoff, and multivariate logistic regression was used to identify independent predictors of adherence. Persistence was assessed via healthcare-engagement metrics over a 360-day observation period. Results: Effective blood pressure control (MAP < 100 mmHg) was achieved by 45.9% of participants. The HBCTS demonstrated good reliability (McDonald’s ω = 0.82). ROC analysis established 51 points as an optimal threshold (sensitivity = 88.0%, specificity = 38.9%). Male gender (OR = 0.47, 95% CI: 0.29–0.75, p = 0.002) and younger age (OR = 1.04 per year, 95% CI: 1.01–1.06, p = 0.001) independently predicted poor adherence. Treatment coverage days showed the strongest correlation with blood pressure control (r = −0.50, p < 0.001). Among participants, 67.7% demonstrated persistence, achieving significantly better blood pressure control than non-persistent patients. Conclusions: The validated HBCTS (≥51 points) provides an efficient screening tool for Romanian primary care settings. Treatment coverage days emerged as the strongest modifiable predictor of blood pressure control (r = −0.50), highlighting medication availability as a key intervention target. Targeted approaches for male and younger patients, combined with systematic medication continuity monitoring, represent evidence-based strategies for reducing cardiovascular morbidity in this population.