Nguyen VT, et al. - Researchers investigated mortality rates among Major League Baseball (MLB) players, including particular causes of death and differences by career length and position, to better understand risks in comparison with the general public. Players (n=16,637) appearing in ≥ 1 MLB games between 1871 and 2006 in the Lahman Baseball Database were linked with the National Death Index. Most MLB players analyzed were white (mean age at MLB debut: 24.3 years; mean number of seasons played: 6.0; mean age at death: 77.1 years). MLB players had significantly lower mortality rates from all causes and many underlying causes of death classifications except neurodegenerative disease vs US males. Longer career length was correlated with lower all-cause mortality rates and higher cancer-related mortality rates, particularly lung and blood cancers. When both underlying and contributing causes of death were considered, results were comparable, except for digestive tract disease-related mortality, genitourinary tract–related mortality, and mortality due to all other causes. Shortstops and second basemen had lower all-cause, cancer-related, and respiratory tract disease-related mortality rates. Catchers had greater genitourinary tract disease-related mortality rates, and outfielders had lower injury-related mortality rates in comparison with pitchers. Among catchers and injury-related mortality among outfielders, no important correlations for genitourinary tract–related mortality was observed. No marked variations in neurodegenerative mortality rate by career length or player position were noted. Lower MLB player mortality rates may be indicative of the healthy worker effect among athletes vs the general population. Lower mortality rates from some causes among players with longer career length may be linked to the sustained fitness required for or other benefits of longer careers. Skin cancers may be associated with sun exposure, but cancer-related mortality may be associated with products consumed or chemicals. Determining specific factors linked to increased cancer rates may aid in prevention strategies, according to the authors.