Short-Term Impact of Concussion in the NHL: An Analysis of Player Longevity, Performance, and Financial Loss

Abstract

Many studies have focused on the long-term impact of concussions in professional sports, but few have investigated short-term effects. This study examines concussion effects on individual players in the National Hockey League (NHL) by assessing career length, performance, and salary. Contracts, transactions, injury reports, and performance statistics from 2008-17 were obtained from the official NHL online publication. Players who sustained a concussion were compared with the 2008-17 non-concussed player pool. Career length was analyzed using Kaplan-Meier survival curves and stratification of player age, experience, and longevity. Player performance and salary changes were evaluated between the years before versus after concussion. Performance and salary changes were compared against non-concussed NHL athletes before/after their career midpoints. Of the 2194 eligible NHL players in the 9-year period, 309 sustained 399 concussions resulting in injury protocol. The probability of playing a full NHL season post-concussion was significantly decreased compared with the non-concussed pool (p < 0.05), specifically 65.0% versus 81.2% at 1 year into a player's career, 49.8% versus 67.4% at 2 years, and 14.6% versus 43.7% at 5 years. Performance was reduced at all non-goalie positions post-concussion (p < 0.05). Players scored 2.5 points/year less following a concussion. The total annualized financial impact from salary reductions after 1 concussion was $57.0 million, with a decrease of $292,000 per year in contract value per athlete. This retrospective study demonstrates that NHL concussions resulting in injury protocol activation lead to shorter career lengths, earnings reductions, and decreased performance when compared with non-concussed controls.

Concussion and National Hockey League Player Performance: An Advanced Hockey Metrics Analysis

“…Athletic performance after sport-related injury, including both concussion and musculoskeletal injury, is an area of growing interest. [18][19][20][21][26][27][28][29][30] Among professional ice hockey players, Kuhn et al 18 found no differences within the same season, whereas Navarro et al 20 noted fewer points scored in the season postconcussion. Nevertheless, Navarro et al 20 compared players with concussions across a longer time period (specifically the season before to the season after the concussion), and the control group consisted of NHL players (n ¼ 937), regardless of other injuries or time loss.…”

“…We identified performance metrics from the previously publicly available WAR-on-Ice 25 Web site, which calculated multiple metrics per player on a game-by-game basis, an approach used by numerous authors. 18,20,26 Two levels of performance metrics were used. In the primary analysis, 6 commonly used advanced metrics encompassing a broad performance spectrum were identified: (1) points per 60 minutes (Points60), (2) Corsi percentage (Corsi%), (3) personal Fenwick shooting percentage (pFen%), (4) scoring chances per 60 minutes, (5) penalty difference, and (6) PDO (not an acronym but sometimes referred to as SVSP% [save percentage shooting percentage]).…”

“…[18][19][20][21][22] After concussion, reduced performance has been noted in both football and baseball players. [18][19][20][21][22] Player performance postconcussion in the NHL has received limited attention, but Kuhn et al 18 identified no changes in either performance or style of play when assessing hockey performance metrics (eg, goals, points, penalty minutes) over 5 games after players returned from a concussion. More recently, using similar metrics to compare performance in subsequent seasons, Navarro et al 20 noted reductions in total points for players who sustained concussions.…”

Short-Term Outcomes of Concussions in Major League Baseball: A Historical Cohort Study of Return to Play, Performance, Longevity, and Financial Impact

“…In line with previous studies examining the short-term effects of SRC in the National Football League (NFL) and National Hockey League (NHL), we hypothesized that decreased career length, performance, and compensation would be observed for players after SRC. 16,17 …”

Evaluating Performance of National Hockey League Players After a Concussion Versus Lower Body Injury

“…We also accounted for opponent level and used mixed models, making the design more robust and more sensitive to changes in performance over time. Navarro et al 25 reported decreased NHL player performance in the season after concussion. However, their control group was a mix of athletes who were either uninjured or had other types of injuries, and they were unable to address whether concussion was associated with worse performance than other injury types.…”