Prevalence and factors associated with uncontrolled systolic blood pressure among treated older adults in Sri Lanka: a nationwide multicenter cross-sectional study

Uncontrolled systolic blood pressure (SBP) is a major modifiable determinant of cardiovascular morbidity and mortality in older adults. This study aimed to evaluate the prevalence, associated factors, and cardiovascular implications of uncontrolled SBP among treated older adults in Sri Lanka. A nationwide multicenter cross-sectional study was conducted in medical outpatient clinics of ten tertiary care hospitals representing all nine provinces of Sri Lanka. A total of 1,339 adults aged ≥ 65 years receiving antihypertensive therapy for at least six months were recruited using systematic sampling. Blood pressure (BP) was measured using a standardized three-reading protocol. Uncontrolled SBP was defined as SBP ≥ 130 mmHg irrespective of diastolic BP, in accordance with contemporary guideline recommendations. Data was collected using interviewer-administered questionnaires and medical record review. Associations between patient characteristics and uncontrolled SBP were assessed using chi-square tests, independent samples t-tests, and multivariable logistic regression analysis. The mean age of participants was 69.4 ± 6.6 years, and 56.8% were female. The mean duration of hypertension was 9.8 ± 8.3 years. Uncontrolled SBP was present in 71.2% of treated older adults. Only 34.4% were receiving dual antihypertensive therapy, while 42.2% remained on monotherapy. Major adverse cardiovascular events (MACE) were reported in 38.2% of participants, and other vascular comorbidities were present in 81.6%. In multivariable analysis, satisfactory income (OR 1.96, 95% CI 1.20–3.20, p = 0.007), low physical activity (OR 1.41, 95% CI 1.07–1.86, p = 0.015), and higher neck circumference (OR 1.01, 95% CI 1.01–1.02, p = 0.014) were independently associated with uncontrolled SBP. Importantly, uncontrolled SBP was significantly associated with MACE (OR 1.31, 95% CI 1.01–1.69, p = 0.044). Medication adherence, dietary salt intake, BMI, and vascular comorbidities were not independently associated with uncontrolled SBP. Over two-thirds of treated older adults in Sri Lanka had uncontrolled SBP, which was more common among participants with MACE. Higher income, low physical activity, and increased neck circumference were associated with uncontrolled SBP among treated older adults. These findings highlight the importance of targeted strategies, including lifestyle modification and improved risk-based management, to optimize BP control in this population.