For those reporting ER-treated injuries , significant effect modification was found for those aged 18 to 30 years ( RR = 2.29 ) , Blacks ( RR = 2.59 ) and Hispanics ( RR = 2.68 ) , high risk-taking ( RR = 1.71 ) , positive RAPS4 ( RR = 3.69 ) , and for motor vehicle ( RR = 3.79 ) and cutting/piercing injuries ( RR = 2.60 ) .