Against the predictions of the linear logistic model,
neither all-cause nor cardiovascular deaths depended on
systolic blood pressure in a strictly increasing manner. The
linear logistic model was rejected by the Framingham data.
Instead, risk was independent of systolic blood pressure for
all pressures lower than a threshold at the 70th percentile
for a person of a given age and sex. Risk sharply increased
with pressure higher than the 80th percentile. Since systolic
blood pressure steadily increases with age, the threshold
increases with age, but more rapidly in women than in men.