Geographical variation of mortality from cardiovascular diseases. The Project 'Myocardial Infarction in mid-Sweden'.

In this study, the geographical variation of the mortality rate in mid-Sweden was studied. Data on mortality from all causes and mortality from cardiovascular diseases, cerebrovascular diseases, ischaemic heart disease (IHD) and non-cardiovascular diseases for men and women 45-74 years of age living in 76 communities in mid-Sweden were obtained from the National Bureau of Statistics. After age standardization, the rates for mortality from all causes and cardiovascular mortality were substantially higher in the Westernmost communities compared with those in the East, whereas for non-cardiovascular mortality there were no systematic differences. The county with the higher rate for IHD had a 60% higher rate for men aged 45-64 years and a 53% higher rate for women aged 45-64 years than the county with the lowest rate. The corresponding excess mortality rates from stroke were 73% for men aged 45-74 and 46% for women aged 45-74 years. The cause of this variation is not known. It is not due to the confounding effect of different age distributions in the communities, differences in the registration of causes of death, or differences in case fatality rate.