Table 4. Risk factors for suffering a concussion or suspected concussion during the regular season.

Risk Factor	Adjusted OR	p value	95% CI
All Players
2010–11 Season	1.62	0.0	1.25, 2.11
2011–12 Season	1.89	0.0	1.47, 2.44
Games on Roster	1.03	0.0	1.03, 1.04
Defenseman	1.26	0.159	0.93, 1.55
Weight	0.997	0.036	0.986, 0.999
NHL Skaters Only
2010–11 Season	1.66	0.002	1.21, 2.29
2011–12 Season	1.70	0.001	1.25, 2.33
Games on Roster	1.03	0.0	1.03, 1.04
Defenseman	1.62	0.008	1.14, 2.31
Fights per 10 Games	1.17	0.046	1.00, 1.37
Years of Experience	1.06	0.103	0.99, 1.15
Minutes per Game	0.96	0.024	0.93, 1.00
Age	0.93	0.046	0.87, 1.00
Height	0.91	0.07	0.85, 0.98

Stepwise logistic regression for the outcome of a player suffering a concussion or suspected concussion during one full regular season was performed. Risk factors tested for all OHL and NHL players were: season (2009–10, 2010–11 or 2011–12), league (NHL or OHL), age, height, weight, position (goalie, center, wing or defense), games of league experience, years of league experience, fights per 10 games, scoring (points per game), penalty minutes per game, games on the roster (games played plus games missed due to injury or suspension), whether the player had incurred a fine or suspension during the year, and the ranking of the player’s team in terms of total penalty minutes during the season. For a subgroup analysis of NHL skaters, average on-ice minutes per game, hits per game, shots blocked per game and salary were also included.