Did early detection and treatment contribute to the decline in ischemic heart disease mortality? Prospective evidence from the Alameda County Study.

In a previous study, the authors reported a 45 per cent decline in ischemic heart disease mortality between cohorts selected to be representative of Alameda County, California, in 1965 and 1974. The decline could not be explained by baseline differences in the distribution of many of the known ischemic heart disease risk factors available for analysis in this cohort. This study reports the results of further analyses which evaluated the hypothesis that early detection and improved treatment contributed to the decline. In multiple logistic analyses adjusted for age, sex, and race, those who reported heart trouble at baseline had an ischemic heart disease mortality decline 2.5 times greater than those who did not (p = 0.01). Those who used preventive health services had an ischemic heart disease mortality decline 2.2 times greater than those who did not (p = 0.03). These interactions were independent of each other and were not explained by adjustment for physical activity, smoking, social connections, or body mass index. There was an increase in the prevalence of self-reported heart trouble between 1965 and 1974, especially among younger age groups. These results are consistent with the hypothesis that early detection and treatment contributed to the decline in ischemic heart disease mortality observed in the Alameda County Study.