The impact of chronic diseases of lifestyle and their major risk factors on mortality in South Africa.

The purpose of this study was to determine the impact of chronic diseases of lifestyle on the mortality pattern of South Africans and to estimate the number of South Africans affected by major risk factors for these diseases. The proportion of deaths due to chronic diseases of lifestyle was calculated from the deaths reported to the Central Statistical Services. This group of diseases was responsible for 24.5% of deaths of all South Africans and 28.5% of those aged 35-64 years whose deaths were reported in 1988. The major causes of death contributing to these figures were cerebrovascular diseases (7.2% of all deaths and 7.9% of deaths of persons aged 35-64 years) and ischaemic heart disease (8.7% of all deaths and 9.6% of deaths of persons aged 35-64 years). The age-standardised prevalence rates for the major risk factors reported in five cross-sectional studies in different areas and groups are compared. Estimates from the reported prevalence rates, based on the size of the South African population recorded in the 1985 census figures, were calculated for the major risk factors. Overall 4.88 million South Africans smoked, the largest group of smokers being black males (2.6 million). for hypertension 5.5 million South Africans had blood pressures above 140/90 mmHg; again the largest groups were blacks (3.0 million). For hypercholesterolaemia and raised low-density lipoprotein cholesterol levels, 4.8 million and 3.1 million South Africans respectively had an increased risk for ischaemic heart disease, blacks having the lowest levels.(ABSTRACT TRUNCATED AT 250 WORDS)