Uncontrolled blood pressure in treated older adults: gaps in control and associated factors from a nationwide multicenter study in Sri Lanka

Hypertension is highly prevalent among older adults and remains a major contributor to cardiovascular morbidity despite pharmacological treatment. Age-related vascular changes, multimorbidity, and polypharmacy complicate blood pressure (BP) control in ageing populations. However, factors associated with uncontrolled BP in older adults, particularly in low- and middle-income countries, remain insufficiently reported. This study aimed to determine the prevalence and associated factors of uncontrolled BP among older adults on treatment in Sri Lanka. A nationwide multicenter cross-sectional study was conducted in outpatient medical clinics of ten tertiary care hospitals representing all nine provinces of Sri Lanka. A total of 1,339 adults aged ≥ 65 years who had been on antihypertensive therapy for at least six months prior to recruitment were enrolled using systematic sampling. BP was measured using a standardized protocol. Uncontrolled BP was defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg according to contemporary clinical guidelines. Data was collected using structured interviewer-administered questionnaires and medical record review. Associations were assessed using chi-square tests, independent samples t-tests, and multiple logistic regression analysis. The mean age of participants was 69.4 ± 6.6 years, and 56.8% were female. Uncontrolled BP was present in 52.4% of treated older adults. Only 34.4% were receiving dual antihypertensive therapy. Vascular comorbidities were highly prevalent (81.6%), and major adverse cardiovascular events (MACE) were reported in 38.2% of participants. In multiple logistic regression analysis, increased neck circumference (OR 1.009, 95% CI 1.001–1.018, p = 0.026) and low/moderate medication adherence (OR 1.357, 95% CI 1.051–1.752, p = 0.019) were independently associated with uncontrolled BP. Gender, socioeconomic status, physical activity, dietary salt intake, alcohol use, smoking, vascular comorbidities, and MACE were not significantly associated with BP control. More than half of treated older adults in Sri Lanka have uncontrolled BP despite on treatment. Suboptimal medication adherence and increased neck circumference, potentially reflecting sleep-disordered breathing, are key contributors to poor BP control in this ageing population. These findings highlight important geriatric care gaps and underscore the need for adherence-focused interventions, optimization of combination therapy, and comprehensive, individualized cardiovascular risk management strategies for older adults. Not applicable.