Mortality under age 50 accounts for much of the fact that US life expectancy lags that of other high-income countries.

Life expectancy at birth in the United States is among the lowest of all high-income countries. Most recent studies have concentrated on older ages, finding that Americans have a lower life expectancy at age fifty and experience higher levels of disease and disability than do their counterparts in other industrialized nations. Using cross-national mortality data to identify the key age groups and causes of death responsible for these shortfalls, I found that mortality differences below age fifty account for two-thirds of the gap in life expectancy at birth between American males and their counterparts in sixteen comparison countries. Among females, the figure is two-fifths. The major causes of death responsible for the below-fifty trends are unintentional injuries, including drug overdose--a fact that constitutes the most striking finding from this study; noncommunicable diseases; perinatal conditions, such as pregnancy complications and birth trauma; and homicide. In all, this study highlights the importance of focusing on younger ages and on policies both to prevent the major causes of death below age fifty and to reduce social inequalities.