Table 2.
Retention and Cannabis Outcomes
| COMPUTER (n=30) | THERAPIST (n=29) | BRIEF (n=16) | statistic | p value | |
|---|---|---|---|---|---|
| Number of MET/CBT sessions attendeda (delivered by computer or therapist) | 4.8 (3.4) | 5.3 (3.4) | 1.4 (0.5) | t = 0.58 | .57 |
| Number of supportive therapist sessions | 2.0 (0.9) | — | — | ||
| Treatment Participation (number of specimens submitted) | |||||
| <3 | 27% | 17% | 31% | X2=7.76 | .26 |
| ≥3 & ≤6 | 20% | 28% | 13% | ||
| >6 & ≤12 | 13% | 7% | 31% | ||
| >12 | 40% | 48% | 25% | ||
| Mean weeks of continuous abstinencec | 2.8 (4.2) | 3.6 (4.4) | 0.8 (2.0) | ||
| THERAPIST vs BRIEF | 5.54 (3.39, 7.93) | < .05 | |||
| COMPUTER vs BRIEF | 4.07 (1.40, 6.99) | < .05 | |||
| THERAPIST vs COMPUTER | 1.47 (–1.91, 4.87) | ns | |||
| Participants available at follow-ups | |||||
| End of Treatment / 9 monthsd | 67% / 67% | 73% / 55% | 69% / 56% | ns/ns | |
| Participants abstinent (end of treatment) | 47% | 45% | 12.5% | ||
| THERAPIST vs BRIEF | X2 = 4.85 | < .05 | |||
| COMPUTER vs BRIEF | X2 = 5.37 | < .05 | |||
| THERAPIST vs COMPUTER | X2 = 0.02 | .89 | |||
| % days cannabis used (past 90 days)e | |||||
| End of Treatment | 26% | 23% | 40% | ||
| THERAPIST vs BRIEF | t= 1.55 | .12 | |||
| COMPUTER vs BRIEF | t = 1.29 | .20 | |||
| THERAPIST vs COMPUTER | t = 0.33 | .75 |
a
comparison of COMPUTER and THERAPIST;
b
mean (SD): Wilcoxon X2
c
arithmetic means (SD); results from BCA bootstrap: estimated mean difference between groups (95% CI)
d
no differences between conditions
e
estimated means from piecewise linear mixed model