Characterizing Frailty Status in the Systolic Blood Pressure Intervention Trial

Area of Science:

• Gerontology
• Clinical Trials
• Cardiovascular Health

Background:

• The Systolic Blood Pressure Intervention Trial (SPRINT) investigates intensive blood pressure (BP) control (120 mm Hg target) for hypertensive, nondiabetic adults.
• Concerns exist regarding potential adverse effects of intensive BP control in older, frail individuals.
• Characterizing frailty in SPRINT is crucial for understanding trial generalizability and the inclusion of diverse older populations.

Purpose of the Study:

• To assess the prevalence and characteristics of frailty within the SPRINT trial population.
• To determine the association between frailty and adverse health outcomes, including falls and hospitalizations.

Main Methods:

• A 36-item frailty index (FI) was developed for 9,306 SPRINT participants.
• Participants were categorized as fit (FI ≤ 0.10), less fit (0.10 < FI ≤ 0.21), or frail (FI > 0.21).
• Recurrent event models analyzed the relationship between FI and self-reported falls, injurious falls, and all-cause hospitalizations.

Main Results:

• Approximately 27.6% (2,570) of SPRINT participants were classified as frail.
• The median FI in participants aged 80+ was 0.18, comparable to population studies.
• A 1% increase in FI significantly correlated with higher risks of falls (HR=1.030), injurious falls (HR=1.035), and hospitalizations (HR=1.038).

Conclusions:

• Large-scale clinical trials like SPRINT can successfully enroll heterogeneous populations, including frail older adults.
• The findings support the inclusion of frail individuals in trials evaluating cardiovascular disease risk reduction.
• Characterizing frailty is essential for interpreting trial results and ensuring representativeness.