The effects of altitude on concussion incidence in the 2013–2017 National Hockey League seasons

Introduction Altitude cannot be adjusted yet can still impact quality of play and concussion incidence. The current body of published evidence evaluating environmental effects on concussion is divided. We aim to systematically compare the prevalence of concussions that occur utilizing 1,000 feet as a marker for high altitude. Our research also takes a novel approach utilizing average games missed as a proxy for concussion severity. Methods Data on concussion incidence for the 2013–2017 National Hockey League seasons was collected utilizing FOX Sports, Hockey Reference and elevation map. We adopted 1,000 feet (304.8 meters) as high-low altitude cutoff. We also evaluated our data utilizing a previously published high-low altitude cutoff of 644 feet. One caveat to our data collection was the striking lack of publicly available data pertaining to the concussions sustained by each NHL team. Data was analyzed utilizing SAS programing. Results We documented 133 concussions through the 2013–2017 NHL seasons. We noted an increase in concussion reporting during the most recent 2016–2017 season compared to previous ones. Effect of altitude variance on concussion rate was evaluated utilizing 644 and 1000 ft as the altitude split. This produced 4 distinct categories: (1) low-low, (2) low-high, (3) high-low, and (4) high-high. We noted a significant difference in concussion rate when teams based at altitude above 1,000 ft played at low altitude. Average games missed demonstrated that teams above 1,000 feet experienced less games missed compared to low altitude teams. Conclusions Though underreported in the total number of concussions, our data suggests that high altitude teams experience a reduction in mean concussion rate when playing at lower altitudes. Our data also indicated a reduction in average games missed post-concussion for higher altitude teams. We hope our findings contribute to a larger discussion about concussion incidence and can be applied to additional sports leagues.