Baseline Quality of Life and Risk of Stroke in the Antihypertensive and Lipid Lowering to Prevent Heart Attack (ALLHAT) Trial

ABSTRACT: BACKGROUND: Quality of Life (QoL) is an integrative health status measure that may predict medical outcomes. No prospective study assessed relationship between QoL, subsequent stroke risk, and post-stroke outcome. OBJECTIVE: Determine how baseline QoL predicted non-fatal stroke, as well as the impact of stroke risk factors on QoL in ALLHAT using visual analogue scale (VAS) – a validated QoL tool. METHODS: ALLHAT randomized hypertensive patients to Chlorthalidone (C), Amlodipine (A) or Lisinopril (L), and used VAS to measure global QoL (0.00 -1.00) at baseline, 2, 4, and 6 yrs. QoL values underwent statistical Torrance transformation (TQoL). Mean QoL and TQoL pre (baseline) and post non-fatal stroke were analyzed. Hazard ratios (HR) and Kaplan-Meier curves for each quartile of baseline QoL were calculated. Baseline QOL, TQoL, and stroke risk factors were used in a multiple linear regression model to predict post-stroke QoL. QoL changes were examined by study arm, age, gender, and race. RESULTS: 28,534 (86%) participants completed at least one VAS. Of the 1,517 strokes; 22% (n=322) were fatal. QoL and TQoL results were similar. Patients who experienced in-trial stroke in C and A arms had lower baseline QoL than those who did not (HR =.71 vs .74, p<0.001and .71 vs .74, p=0.004, respectively), but not in L (HR=.73 vs .74, p=0.24). A 10% increment in baseline QoL or TQoL was associated with 5% and 7% reduction in the risk of stroke respectively (adjusted HR; 95% CI = .95; .91 -.99) and .93; .89 –.98). In risk factor adjusted models, lowest baseline QoL quartile had a 20% higher stroke risk (HR =1.20; 95% CI: 1.00-1.44) than highest quartile. QoL worsened post stroke, dropping most in elderly >75 yrs (-.08 units, p<0.0001), compared to groups 55-64 (-.04, p<0.05) and 65-75 yrs, (-.07, p <0.0001), and in A arm (-.09 units, p<0.0001) compared with C (-.05, p=0.0006) and L (-.07, p< 0.0001), but did not differ by gender or race. In a multiple linear regression model, baseline QoL predicted post-stroke QoL. CONCLUSIONS: Lower baseline QoL was associated with higher stroke risk. Qol was lower post stroke. Baseline QoL was the only factor predicting post stroke QoL, and QoL change increased with age. Investigation of factors determining QoL may be fertile ground for stroke risk reduction.