Secular trends in cardiovascular disease mortality, incidence, and case fatality rates in United States adults
Description
Background. Mortality from cardiovascular diseases (CVD) has declined substantially in the US during the past several decades. However, it is not certain to what extent the decline in CVD mortality is due to a reduction in incidence and/or improvements in case-fatality rates Objectives. To compare age-adjusted CVD mortality, incidence, and case-fatality rates between 1971--1982 and 1982--1992, to evaluate the contribution of CVD incidence and case-fatality rate to the secular trends in CVD mortality, and to compare CVD rates among normotensive and hypertensive, high socioeconomic and low socioeconomic status, and physically active and inactive participants of the National Health and Nutrition Examination Survey I Epidemiologic Followup Study (NHEFS). Methods. The NHEFS cohort included 14,407 persons 25--74 years of age who completed a medical examination at NHANES I in 1971--75. Two national cohorts of adults aged 35 to 74 years were created from these data. 10,869 subjects in the 1971--82 cohort and 9,774 subjects in the 1982--92 cohort were available for the analysis. The cohorts were followed-up prospectively for CVD incidence and mortality for an average of 9.5 and 8.4 years, respectively. Follow-up interviews, hospital record reviews, and death certificate searches were conducted in 1982--84, 1986, 1987, and 1992--93 as part of the NHEFS Results. Age-adjusted CVD mortality declined by 31 percent from 1971--1982 to 1982--1992. The mortality decline was observed among all race-gender groups, and normotensive and hypertensive, low and high socioeconomic status, and physically active and inactive subjects, albeit less significantly in hypertensive, low socioeconomic, and physically inactive subjects. The decrease in overall CVD mortality was accompanied by a decline in the CVD incidence and improvements in 28-day and long-term case fatality rates in all groups, but improved case fatality rate was the major contributor to the CVD mortality decline among hypertensives, low socioeconomic status, and inactive participants Conclusions. These findings suggest that the decrease in mortality from CVD between the periods was due to a combined effect of reduced incidence and, most importantly, improvements in case fatality rates of CVD. However, the decline was mainly due to the improvement in survival in hypertensive, low socioeconomic status and physically inactive subjects