Table 2.
Cox proportional hazards analysis to evaluate the relationship between mortality and systolic BP by age
| Age Group | Hazard Ratio (95% CI) per Baseline Systolic BP | ||||
|---|---|---|---|---|---|
| ≤120 mmHg(n=5357) | 121–130 mmHg(n=4268) | 131–140 mmHg(n=4512) | 141–150 mmHg(n=3038) | >150 mmHg(n=3840) | |
| 65–70 yr (n=4164) | 1.41 (1.10 to 1.81) | 1.36 (1.05 to 1.76) | 1.0 | 1.40 (1.06 to 1.85) | 1.43 (1.08 to 1.90) |
| 71–80 yr(n=9278) | 1.17 (1.03 to 1.32) | 1.08 (0.95 to 1.23) | 1.0 | 0.92 (0.80 to 1.05) | 1.00 (0.88 to 1.14) |
| >80 yr (n=7573) | 1.27 (1.09 to 1.47) | 1.17 (1.0 to 1.37) | 1.0 | 0.90 (0.75 to 1.07) | 0.86 (0.73 to 1.02) |
This analysis adjusts for heart failure, cardiovascular disease, tobacco use, and level of eGFR and stratifies on diabetes, sex, body mass index, and diastolic BP. Stratification was used to accommodate violations in the proportional hazards principle. The cardiovascular disease variable is a composite variable that includes coronary artery disease, peripheral vascular disease, and stroke. The diastolic BP is incorporated as a tiered variable using initial diastolic BP to categorize patients as having diastolic BP ≤60, 61–80, 81–90, and >90 mmHg. Body mass index is incorporated as a tiered variable (≤18.5, >18.5 and ≤30, >30 kg/m2). Tobacco use is incorporated as a dichotomous variable (yes/no) for tobacco use in the 2 years before index date. 95% CI, 95% confidence interval.