Figure 1.

Usual systolic blood pressure vs cardiac (A) and stroke (B) mortality at ages 35–69 years in Chennai, India

Rate ratios were adjusted for major confounders (age, sex, education, socioeconomic status, smoking, and alcohol) and body-mass index, and omitted the first 2 years of follow-up. Exclusions are as per table 1. For each systolic blood pressure category, the area of the square is inversely proportional to the variance of the category-specific log risk, which also determines the 95% CI (represented by error bars).