The healthy worker effect in major league baseball revisited.

We investigated the "healthy worker effect" (HWE) in major league baseball. Ages of death of major league baseball players who debuted between 1900 and 1939 were obtained and differences between those ages and age-adjusted life expectancies were examined to determine if longevity increased with career length, controlling for decade in which a player debuted, player position, and handedness. Major league baseball players (N = 4,492) lived an average of 4.8 (+/- 15.0 Standard deviation [SD]) years longer than age-matched controls from the general public. Career length significantly and incrementally increased longevity of players from an average of 4.1 years for players playing one season to 7.4 years for players playing 11 or more years. None of the other factors, nor any of the interactions, was statistically significant. These data provide strong support for the HWE in professional baseball.