Systolic Blood Pressure Trajectory, Frailty, and All-Cause Mortality >80 Years of Age: Cohort Study Using Electronic Health Records

BACKGROUND:Clinical trials show benefit from lowering systolic blood pressure (SBP) in people ≥80 years of age, but nonrandomized epidemiological studies suggest lower SBP may be associated with higher mortality. This study aimed to evaluate associations of SBP with all-cause mortality by frailty category >80 years of age and to evaluate SBP trajectories before death. METHODS:A population-based cohort study was conducted using electronic health records of 144 403 participants ≥80 years of age registered with family practices in the United Kingdom from 2001 to 2014. Participants were followed for ≤5 years. Clinical records of SBP were analyzed. Frailty status was classified using the e-Frailty Index into the categories of fit, mild, moderate, and severe. All-cause mortality was evaluated by frailty status and mean SBP in Cox proportional-hazards models. SBP trajectories were evaluated using person months as observations, with mean SBP and antihypertensive treatment status estimated for each person month. Fractional polynomial models were used to estimate SBP trajectories over 5 years before death. RESULTS:During follow-up, 51 808 deaths occurred. Mortality rates increased with frailty level and were greatest at SBP