Ischaemic heart disease mortality among men in Norway: reversal of urban-rural difference between 1966 and 1989.

Abstract

This study aimed to examine regional urban-rural differences in mortality from ischaemic heart disease, including sudden death of unknown cause (IHD/SUD) in Norway from 1966-89, for men and women aged 30-69 years. Analysis was based on vital statistics. Regional mortality rates were obtained by aggregating the 443 municipalities in Norway into urban, rural, and intermediate municipalities. Norway. In 1966-70 the age adjusted IHD/SUD mortality in the age group 30-69 years was higher in urban than in rural areas; for men by 31% (95% CI 27%, 36%) and for women by 28% (95% CI 19%, 36%). In 1986-89 the IHD/SUD mortality for men showed a reversed urban-rural gradient: it was 8% (95% CI 2%, 13%) higher in rural than in urban areas. The mortality rates for women were equal for both these aggregates. For men the results indicate that IHD/SUD mortality peaked first in urban municipalities and then, but at a lower level, in rural areas. For women there was a substantial decline in IHD/SUD mortality between 1966 and 1989, but an actual peak could not be demonstrated in any of the three aggregates during the period. The decline in IHD/SUD mortality among women was steepest in urban municipalities and least noticeable in rural municipalities, but the decline tapered off towards the end of the study period. The results confirm a phase-shifted peak in IHD/SUD mortality, which began in towns and ended in rural areas, and provides clues to the main underlying factors in the IHD epidemic at the population level.