Marginal difference in before–after changes in substance use among participants
| Indicator | Estimate of group difference in before–after changes (95% CI) |
|---|---|
| Percentage of participants reporting cigarette use | −2.8 (−15.3 to 0.6) |
| Cigarette count among smokers | −1.6 (−6.4 to −1.3) |
| Percentage of participants reporting alcohol use | −0.5 (−8.7 to 1.8) |
| Percentage of participants reporting cannabis use | −6.4 (−17.0 to −1.7) |
| Percentage of participants reporting street drug use | −2.0 (−4.3 to 1.7) |
| Percentage of participants reporting any substance use | −5.6 (−13.8 to 2.6) |
Note: CI = confidence interval. Marginal (population averaged) estimates of differences between the NFP and comparison groups (i.e., estimates of the before–after changes in probability for positive binary substance outcomes and rate for cigarette count) were calculated using estimated regression coefficients and estimated population distribution of random effects from generalized linear mixed-effect models.