Trends in coronary heart disease--has the socio-economic differential changed?
To compare both trends in rates of coronary heart disease and levels of coronary risk factors between different socio-economic groups. Rates of coronary events for men and women aged 25 to 69 years were estimated from a population-based register in the Lower Hunter Region of New South Wales from 1985 to 1993. Risk factor levels were estimated for men and women aged 35 to 64 years from three surveys of risk factors conducted in 1983, 1988/89 and 1994 in the same study population. There was a decline in major coronary events from 1985 to 1993. The greatest decline was for fatal coronary events, which fell by between 4.3% and 9.1% per year. Trends in event rates were similar for all socio-economic groups, except for trends in non-fatal definite myocardial infarction among women. Women from the areas with high socio-economic status tended to have a greater reduction in non-fatal definite myocardial infarction compared with women from low socio-economic areas. Trends in risk-factor levels were similar except the prevalence of cigarette smoking among women from the lowest quintile of socio-economic status did not decline. Prevention strategies seem to have had a beneficial impact on this population, resulting in similar declines in rates of coronary events for all socio-economic groups. However, event rates are still high, suggesting a further reduction in mortality and morbidity is possible. This could be achieved by further reductions in smoking, cholesterol and blood pressure, especially among people from areas with low socio-economic status.