comparison of trends of coronary heart disease mortality in Australia, USA and England and Wales with reference to three major risk factors-hypertension, cigarette smoking and diet.

A comparison has been made of the recent changes in coronary heart disease mortality in Australia, the USA, and in the United Kingdom (England and Wales). Sharp declines in mortality dating from 1966 in Australia and from 1968 in the USA in both sexes contrast with a persistent increase in men in England and Wales until 1972 (after which a sight fall occurred) and a consistent slight fall in women since 1950. An investigation has been made of changes in 3 major risk factors-hypertension, cigarette smoking and diet in the 3 countries in an attempt to determine to what extent such changes might correlate with the different patterns of mortality. There has been a progressive and similar fall in mortality due to hypertension in both sexes in all 3 countries since 1950. There was a rise in cigarette smoking in all 3 countries from 1947 followed by a fall in the USA from 1963 and a more recent fall in men in Australia. There has been a levelling off of smoking in the United Kingdom in middle-aged and older men but not in women where smoking rates have increased from 1950 since when there has been a progressive slight fall in overall coronary heart disease mortality (although there is evidence of a recent rise in younger women.) Changes in dietary constituents (meat, eggs, milk and cheese, butter or margarine) have been examined by reference to aggregate consumption data. In Australia and the USA increases in vegetable fat consumption have occurred since 1950 with a reduction in animal fat in Australia but not in the USA. In the United Kingdom increases in vegetable fat have not been observed while there has been some increase in animal fat. It is concluded that the different patterns of coronary heart disease mortality in the 3 countries do correlate to some extent with changes in diet and cigarette smoking.