Same-Year Repeat Concussions in the National Football League: Trends from 2015 Through 2019

Background: Sport-related concussion (SRC) prevention and management is a focus of the National Football League (NFL). While most prior reports evaluated sport-related concussion incidence, few have studied same-year repeat concussions. This study aimed to evaluate the frequency of same-year repeat concussions in the NFL.

Methods: A retrospective, observational cohort study of same-year repeat concussions in the NFL from 2015 to 2019 was performed. The NFL's electronic health record was reviewed for players sustaining concussions and same-year repeat concussions. Wilcoxon rank sum tests were used to calculate same-year repeat concussion rates, and risk ratios and 95% confidence intervals were estimated using log-binomial regression.

Results: From 2015 to 2019, the risk of sustaining a same-year repeat concussion in the NFL was 0.38%-0.69% per season. Among players who sustained a concussion, the risk of a same-year repeat concussion was 5.3%-8.3%, which did not differ significantly from the risk of sustaining a single concussion (6.2%-8.3%). There was a median of 38 participation days between initial and same-year repeat concussion. Players missed more time from same-year repeat concussions (median 12 days) compared with both single (median 9 days; P < 0.0001) and initial (median 9.5 days; P = 0.002) concussions.

Conclusions: The risk of a repeat concussion was similar to the risk of sustaining a single concussion among NFL players. More time was missed following a same-year repeat concussion compared with single or initial concussions. Further research is needed to maximize player safety and minimize same-year repeat concussions.