Five-year mortality in the city of Bergen, Norway, according to age, sex and blood pressure

Abstract

The City of Bergen was covered by a Mass Miniature Radiology Survey in 1963-64. On the initiative of the University of Bergen, examinations of BP were included. The initial survey has been reported previously (1). This analysis concerns the relationship between the 5 1/4-year cause-specific mortality and BP. Non-attenders have excess mortality in relation to attenders and this is mostly explained by a generally high mortality among bedridden people. The age-specific total mortality shows a clear pattern of a general increase with increasing BP. At high systolic BP levels, the 5-year mortality is independent of whether the age is 45 or 75. The systolic age-adjusted curve for males increases quite linearly, while the diastolic curve is more U-shaped. Thus, when comparing the predictive power of BP, allowance must be made for this fact. Using a second order polynomial prediction function, this conclusion is reversed. The mortality from cerebral stroke shows a dramatic increase with increasing BP. The diastolic curve shows a bend-off for high values, above 110 mmHg. This may be due to the offer of treatment which such patients received after the screening. Also the CHD mortality curve flattens for high BP values, especially for diastolic BP.