Table 2.
Intervention effect sizes for any drug use, marijuana use, and drugs other than marijuana, for observed data and hypothetical scenarios for those lost to follow-up
| Any drug use | Marijuana only | Cocaine, opiates, or amphetamines | |
|---|---|---|---|
| Observed data | |||
| Odds ratio (95% CI) | 2.48 (0.59, 10.42) | 2.13 (0.58, 7.78) | 2.41 (0.66, 8.83) |
| Logit d | 0.50 | 0.42 | 0.48 |
| N | 76 | 76 | 76 |
| Urinalysis data only | |||
| Odds ratio (95% CI) | 1.93 (0.65, 5.69) | 1.63 (0.57, 4.66) | 4.67 (0.49, 44.05) |
| Logit d | 0.36 | 0.27 | 0.85 |
| N | 70 | 70 | 70 |
| Presuming 0% success in all lost to f/u | |||
| Odds Ratio (95% CI) | 2.38 (0.58, 5.90) | 2.04 (0.58, 7.24) | 1.39 (0.64, 3.01) |
| Logit d | 0.48 | 0.39 | 0.18 |
| N | 107 | 107 | 107 |
| Applying observed success rates for control and intervention groups to participants lost to attrition | |||
| Odds ratio (95% CI) | 2.67 (0.78, 9.11) | 1.92 (0.65, 5.63) | 2.19 (0.75, 6.44) |
| Logit d | 0.54 | 0.36 | 0.43 |
| N | 107 | 107 | 107 |
| Switching observed success rates for control and intervention groups | |||
| Odds ratio (95% CI) | 1.3 (0.42, 4.06) | 1.43 (0.50, 4.08) | 1.23 (0.44, 3.47) |
| Logit d | 0.14 | 0.20 | 0.11 |
| N | 107 | 107 | 107 |
Note. Marijuana use reflects use weekly or greater by self-report, and/or qualitative urinalysis. Other drug use reflects self-reported use in the past 3 months and/or a positive urinalysis, except where specified (urinalysis data only).