Impact of the 7-Day Disabled List Rule Change on Economics and Performance After Reported Concussion Injuries in Major League Baseball

Abstract

Background: The incidence of concussions is increasing in Major League Baseball (MLB), and the cost of these injuries in 2008 was reportedly as high as US$423 million. Team officials are more aware of concussion injuries, and one measure to address this issue was the creation of a concussion-specific 7-day disabled list (DL) in 2011. Purpose: To evaluate concussion trends among MLB players and the impact of concussion-specific 7-day DL status on postinjury player performance and team financials. Study Design: Descriptive epidemiology study. Methods: From 2005 to 2016, a total of 112 players placed on the DL because of a concussion were identified using the MLB website and were verified using established news databases. Salary information for players was collected using MLB published data, and cost was calculated with a previously published formula utilizing the injured player’s salary per game and adding the cost of his replacement. Performance metrics were compared before and after the rule change. Results: The mean number of days on the DL decreased from 38.8 before 2011 to 29.2 after 2011. The mean annual cost per player before 2011 was $1.1 million and decreased to $565,000 after the rule change. Regression analyses demonstrated a downward trend in the mean cost (R = –0.61, P