By spring of 12th grade , students in CTC communities were more likely than students in control communities to have abstained from any drug use ( adjusted risk ratio [ ARR ] = 1.32 ; 95 % CI , 1.06-1 .63 ) , drinking alcohol ( ARR = 1.31 ; 95 % CI , 1.09-1 .58 ) , smoking cigarettes ( ARR = 1.13 ; 95 % CI , 1.01-1 .27 ) , and engaging in delinquency ( ARR = 1.18 ; 95 % CI , 1.03-1 .36 ) .