Social class differences in years of potential life lost: size, trends, and principal causes.

British social class differences in mortality are examined in terms of years of potential life lost, a measure that gives more weight to deaths that take place at younger ages. It shows wider class differences during the years of working life than those found when mortality is expressed in terms of standardised mortality ratios. Examination of the change in class differences between 1971 and 1981 for all causes of death combined and for the three categories of death which during these ages make a major contribution to total years of potential life lost shows complex changes. Inequalities in years of potential life lost have increased between 1971 and 1981, during which all the principal causes of death have shown stationary or rising rates among the manual classes. The use of years of potential life lost as a measure of population health trends focuses attention on the major contribution of violent death, which occurs mainly in younger men, to widening class differences in mortality.