Paired Comparison of Observed and Expected Coronary Heart Disease Rates over 12 Years from the Atherosclerosis Risk In Communities Study

PurposeTo quantify the relationship between coronary heart disease (CHD) risk factor levels and changes over time and population-wide CHD morbidity and mortality.MethodsWe used a paired cohort and community surveillance of hospitalized myocardial infarction and CHD deaths of community members 53 to 64 years of age in four geographic areas to compare observed community CHD to expected CHD rates and trends based on cohort risk factors.ResultsObserved CHD rates declined by 1% to 3% per year in all communities except one, whereas CHD death rates declined 3% to 6% per year in all communities. Risk factor trends predicted a 2% to 3% per year decline in both total events and death. In all communities except one, expected rates of total CHD events were lower than the observed rates, whereas expected and observed CHD death rates were similar. Across all communities women had a higher CHD death rate than expected.ConclusionOverall, trends in CHD risk factors provide a useful indicator of changes in community event rates and of CHD death, but caution is warranted in prediction of absolute risk of CHD events.