Table 4.
Logistic Regression on Cocaine-Negative Urine Toxicology Screen at Follow-Up
| Month 1 | Month 3 | Month 6 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B | SE B | p | OR | 95% CI | B | SE B | p | OR | 95% CI | B | SE B | p | OR | 95% CI | |
| Baseline frequency | −0.09 | 0.03 | .00 | 0.91 | [0.86, 0.96] | −0.10 | 0.03 | .00 | 0.91 | [0.86, 0.96] | −0.11 | 0.03 | .00 | 0.90 | [0.85, 0.95] |
| Attendance | 0.00 | 0.01 | .96 | 1.00 | [0.99, 1.02] | 0.00 | 0.01 | .65 | 1.00 | [0.99, 1.02] | 0.02 | 0.01 | .01 | 1.02 | [1.00, 1.04] |
| Study protocol | −0.09 | 0.21 | .66 | 0.91 | [0.61, 1.37] | 0.22 | 0.25 | .37 | 1.25 | [0.77, 2.02] | 0.02 | 0.25 | .94 | 1.02 | [0.63, 1.65] |
| Homework | 0.01 | 0.01 | .11 | 1.01 | [0.99, 1.03] | 0.02 | 0.01 | .01 | 1.02 | [1.01, 1.04] | 0.01 | 0.01 | .05 | 1.01 | [1.00, 1.03] |
| (constant) | 1.25 | 0.88 | .16 | 3.50 | 0.03 | 0.82 | .97 | 1.03 | −0.13 | 0.90 | .88 | 0.88 | |||
| Model Statistics | |||||||||||||||
| −2 log likelihood | 125.22 | 127.78 | 109.30 | ||||||||||||
| χ2(4) | 13.99 | 21.77 | 26.08 | ||||||||||||
| p | .01 | .00 | .00 | ||||||||||||
| Nagelkerke R2 | 0.17 | 0.24 | 0.31 | ||||||||||||
| % correct | 64.4 | 71.6 | 73.0 | ||||||||||||
| n | 101 | 109 | 100 | ||||||||||||
Note. Bold text denotes significance at p < .05. Baseline frequency = days of self-reported cocaine use in 28 days prior to trial. Attendance = percentage of sessions attended. Homework = percentage of homework adherence.