Table 5 History of previous concussion and incident concussion rate
From: Epidemiology of sports-related concussion in seven US high school and collegiate sports
Number of previous concussions within the past 24 months | No. of incident concussions | Athlete-exposures | Rate per 100,000 athlete-exposures | 95 %CI | CLR | Rate ratio | 95 %CI | CLR |
|---|---|---|---|---|---|---|---|---|
None | 247 | 1,228,161 | 20.1 | 17.6, 22.6 | 1.3 | 1.0 | (reference) | –– |
1 | 90 | 174,923 | 51.5 | 40.8, 62.1 | 1.5 | 2.6 | 2.0, 3.3 | 1.6 |
2 or more | 38 | 34,147 | 111.3 | 75.9, 146.7 | 1.9 | 5.5 | 3.9, 7.8 | 2.0 |