Abstract
BACKGROUND
Stroke is a major cause of morbidity and mortality worldwide, with hypertension being its most important modifiable risk factor. Although the association between elevated blood pressure and stroke is well established, the extent to which longitudinal blood pressure patterns influence the timing of stroke remains poorly understood, particularly in low-resource settings. We investigated the association between longitudinal systolic and diastolic blood pressure trajectories and time to stroke among hypertensive patients in Ethiopia.
METHODS
We conducted a retrospective cohort study of 494 newly diagnosed hypertensive patients receiving follow-up care at two general hospitals in Benishangul-Gumuz, Ethiopia, between January 1, 2015, and September 1, 2024. Time to stroke was analyzed using a Cox proportional hazards model, while repeated systolic and diastolic blood pressure measurements were modelled using linear mixed-effects models. The longitudinal and survival processes were jointly estimated using a Bayesian multivariate joint modelling framework. Posterior adjusted hazard ratios (AHRs) with 95% credible intervals (CrIs) were estimated.
RESULTS
The incidence of stroke was 2.19 per 100 person-years (95% CI: 1.60-2.64). Higher current underlying systolic and diastolic blood pressure levels were associated with increased stroke risk, with posterior AHRs of 3.25 (95% CrI: 1.85-5.83) and 2.32 (95% CrI: 1.35-4.27), respectively. Older age (≥65 years; AHR: 6.18; 95% CrI: 2.32-18.05), comorbidity (AHR: 4.00; 95% CrI: 1.72-10.25), and stage II hypertension (AHR: 4.06; 95% CrI: 1.49-16.36) were associated with earlier stroke occurrence. Rural residence was associated with a lower hazard of stroke (AHR: 0.16; 95% CrI: 0.05-0.40).
CONCLUSIONS
Higher longitudinal systolic and diastolic blood pressure trajectories were associated with earlier stroke occurrence. These findings support regular blood pressure monitoring and targeted prevention strategies among older adults and patients with comorbidities in similar resource-limited settings.