Declining cardiovascular mortality.

IN THE 20 years prior to 1983 the overall death rate for the cardiovascular diseases declined an impressive 36% nationwide. The rate per year.declined in 18 of these years, declining 1.5% per year between 1963 and 1973 and 3.3% per year since then. Because this group of iiseases accounts for one-half of all deaths, a death rate that is 36% lower in 1982 than in 1963 translates into about 500,000 fewer deaths in 1982 than would have been projected based on rates in 1963. This improvement in cardiovascular mortality is the main reason that total mortality has declined 26% since 1963 and that average life expectancy at age 35 increased 2.6 years during the 10 years from 1972 to 1982, a greater increase than during any decade since vital statistics were first published in 1900. Of even greater significance is the remarkable reversal in the death rate trend for the major cardiovascular subgrouip, coronary heart disease. From an epidemic rise in the rate until the mid-1960s, the trend turned downwards and declined 37% between 1963 and 1982 (figure 1). There has also been marked acceleration in the downward trend since 1972 for stroke and all cardiovascular diseases. It is still essentially unknown, however, whether these declines in mortality are occurring more in hospitalized or in nonhospitalized segments of the population, i.e., whether declines are occurring in the incidence of new cases or whether there has been a change in the prognosis, severity, case-fatality, and survivorship after development of cardiovascular disease. These major gaps in knowledge stand in the way of determrining causes of the decline in cardiovascular mortality. Even if such information can be obtained, determining causation would still be difficult if the