Table 2.
Mixed Linear Logistic Regression Models Estimating the Effective of Motivational Interviewing on the Likelihood of Marijuana Use at Follow-Up (n = 332 subjects observed on 83,052 person days).
| Model 1 | Model 2 | ||||
|---|---|---|---|---|---|
| Fixed Effects | OR | 95%CI | OR | 95%CI | |
| Treatment (MI = 1) | 1.28 | (0.76 – 2.17) | 1.15 | (0.49 – 2.70) | |
| Any Desire To Quit (Yes = 1) | 0.32** | (0.15 – 0.68) | |||
| Time | |||||
| Month 1 | 0.62** | (0.49 – 0.79) | 0.43** | (0.30 – 0.62) | |
| Month 3 | 0.75 | (0.57 – 1.00) | 0.44** | (0.26 – 0.74) | |
| Month 6 | 0.63** | (0.46 – 0.85) | 0.41** | (0.24 – 0.72) | |
| Treatment by Time | |||||
| Month 1 | 0.77 | (0.53 – 1.12) | 1.41 | (0.77 – 2.58) | |
| Month 3 | 0.53** | (0.33 – 0.86) | 1.17 | (0.54 – 2.52) | |
| Month 6 | 0.74 | (0.47 – 1.17) | 1.44 | (0.65 – 3.22) | |
| Treatment by Quit Desire | 0.96 | (0.33 – 2.73) | |||
| Quit Desire by Time | |||||
| Month 1 | 1.64* | (1.02 – 2.63) | |||
| Month 3 | 2.19* | (1.18 – 4.07) | |||
| Month 6 | 1.78 | (0.94 – 3.37) | |||
|
Treatment by Quit Desire by Time |
|||||
| Month 1 | 0.42* | (0.20 – 0.90) | |||
| Month 3 | 0.31* | (0.12 – 0.83) | |||
| Month 6 | 0.35* | (0.13 – 0.91) | |||
|
Random Effects |
|||||
| Subject (Variance) | 4.99** | 4.56** | |||
| Log L | - | - | |||
| 36908.8 | 36257.6 | ||||
p < .05,
**
p < .01
Model 2 includes n=328; 4 persons missing Quit Desire response