The recent decrease in CHD mortality.

Between 1968 and 1973 coronary heart disease (CHD) mortality in the United States decreased for 4 out of 5 consecutive years. This is in marked contrast with the increasing trend prior to 1960 and the flat trend in the 1960's. All race, sex and adult age groups experienced a decrease between 1968 and 1972, the overall age-adjusted rate decreasing 7.3% during this period. Decreases of similar magnitudes also occurred for all causes of death combined and for every major cause except cancer, violence, and cirrhosis of the liver.Although the recent decrease in the mortality rate for CHD has been small, the decrease appears to be real. Most of the decrease, however, appears to be due to epidemic fluctuations in the incidence of the respiratory diseases. It is concluded that fluctuations in CHD mortality since the early 1960's are largely minor perturbations arising from extraneous sources rather than from changes in the incidence or prognosis of this disease.