Table 1

 Measured parameters and minimum and maximum incidence estimates across different observation strategies

ParameterBCAHA official injury reportsDirect observationRetrospective survey
Male (PW, B, M)Female (all levels)Volunteer reportsElite (male)Elite (female)Non-elite
PW, Pee wee; B, Bantam; M, Midget; CX, concussion; IOC, incident of concern. *Per 1000 PGH.
Time period1 season1 season3.5 months2 seasons2 seasons2 Seasons
No. of players at risk195485017792475309107
No. of CX or IOC*60722796926
    Minimum no.202014808040
    Maximum no.505025100100100
    Minimum incidence*
    Maximum incidence*
    Minimum no.97 74025 0852772950061801070
    Maximum no.244 35062 713495011 87577252675
    Minimum incidence*
    Maximum incidence*0.610.287.948.3211.1724.30