Study Methods

Abstract

This chapter provides an overview of the data sources , study design , methods, hypotheses , and statistical plan . Data were obtained from a variety of reliable online sources, including the Baseball Reference web-site. In this retrospective cohort study, former Major League Baseball players who played anytime between 1947 and 1986 are divided into 3 groups based on race/Hispanic origin; African-Americans, non-Hispanic whites, and Hispanics. All-cause mortality risk is assessed among these 3 groups of former players. Using the vital status end-date of January 1, 2018, the mortality status of all cohort members is determined. Based on previously published general population and professional athlete literature, the prediction is that former African-American Major League Baseball players will have elevated mortality risk compared to non-Hispanic white and Hispanic players, and that these effects will persist when other potentially important variables are controlled in the analysis. It is further hypothesized that there will be no significant difference in mortality risk between Hispanics and non-Hispanic white players. The primary outcome variable is time to all-cause mortality. Cox proportional hazards regressions will be used to estimate and compare mortality risk for the 3 groups of interest.