Purpose: To assess the effects of changes in cardiovascular disease incidence and case fatality rates on secular trends in mortality in the U.S. population between 1971-1982 and 1982-1992.
Methods: Using data from the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study, two cohorts (10,869 subjects in the 1971-1982 cohort and 9774 in the 1982-1992 cohort) of participants aged 35 to 74 years were created. Baseline medical history questionnaires were administered in 1971-1975 and 1982-1984, with follow-up interviews, hospital record reviews, and death certificate searches conducted in 1982-1984, 1986, 1987, and 1992.
Results: Between 1971-1982 and 1982-1992, age-standardized cardiovascular disease mortality declined from 79.1 (95% confidence interval [CI]: 75.2 to 83.0) to 53.0 (95% CI: 49.5 to 56.5) per 10,000 person-years, while cardiovascular disease incidence rates decreased from 293.5 (95% CI: 284.5 to 302.4) to 225.1 (95% CI: 216.6 to 233.5) per 10,000 person-years. The 28-day case fatality rate for cardiovascular disease declined from 15.7% (95% CI: 14.5% to 16.8%) to 11.7% (95% CI: 10.3% to 13.0%). After adjustment for age, sex, and race, rates were 31% lower for cardiovascular disease mortality, 21% lower for incidence, and 28% lower for 28-day case fatality in the 1982-1992 cohort than in the 1971-1982 cohort (each P <0.001).
Conclusion: The decrease in cardiovascular disease mortality between 1971-1982 and 1982-1992 was due to declines in both the incidence and case fatality rates in this national sample. These findings suggest that both primary and secondary prevention and treatment contributed to the decline in cardiovascular disease mortality in the United States.