Table 1.

Risk differences (RD) of the effect of voucher receipt on the mediator by outcome sample (marginal effects, adjusting for baseline covariates and adherence, Z). CI indicates confidence interval.

Mediator	Boys RD (95% CI)	Girls RD (95% CI)
Cigarette Use Sample
Feels safe at school	0.033 (0.023, 0.043)	0.001 (−0.002, 0.005)
Positive school climate	0.036 (0.027, 0.046)	−0.008 (−0.012, −0.005)
Participates in after-school sport or club	−0.004 (−0.007, −0.000)	0.006 (0.005, 0.008)
Has friends who use drugs	−0.004 (−0.023, 0.016)	0.032 (0.019, 0.044)
Marijuana Use Sample
Feels safe at school	0.030 (0.026, 0.034)	0.026 (0.021, 0.032)
Positive school climate	0.042 (0.036, 0.047)	−0.012 (−0.020, −0.005)
Participates in after-school sport or club	−0.008 (−0.014, −0.002)	0.001 (−0.004, 0.005)
Has friends who use drugs	0.027 (0.012, 0.041)	0.048 (0.028, 0.068)
Problematic Drug Use Sample
Feels safe at school	0.030 (0.024, 0.037)	−0.028 (−0.032, −0.025)
Positive school climate	0.035 (0.028, 0.042)	−0.008 (−0.011, −0.004)
Participates in after-school sport or club	−0.003 (−0.005, 0.000)	0.003 (0.002, 0.004)
Has friends who use drugs	0.014 (−0.001, 0.028)	0.032 (0.019, 0.044)