Table 4.
Effect of intervention and booster condition on process variables
| Measure | BMI (N = 111) M (SD) | CDI (N = 111) M (SD) | BST (N = 114) M (SD) | No BST (N = 108) M (SD) | df | F (Time) | F (Interv. x Time) | F (BST x Time) |
|---|---|---|---|---|---|---|---|---|
| Motivation | ||||||||
| Baseline | 5.25 (3.40) | 5.51 (3.44) | -- | -- | ||||
| Post-intervention | 5.82 (3.67) | 5.90 (3.32) | -- | -- | 1,182 | 4.93* | 0.16 | -- |
| Perception of peer drinking | ||||||||
| Baseline | 3.15 (0.79) | 3.20 (0.78) | 3.16 (0.76) | 3.19 (0.76) | ||||
| 3 mo. follow up | 2.96 (0.71) | 3.00 (0.80) | 3.02 (0.74) | 2.94 (0.77) | 1,202 | 9.48** | 0.05 | 0.69 |
| 12 mo. follow up | 2.86 (0.68) | 3.12 (0.82) | 2.99 (0.78) | 2.99 (0.75) | 1,206 | 7.95** | 3.25† | 0.21 |
| Behavioral strategies | ||||||||
| Baseline | 61.20 (12.88) | 64.43 (14.42) | 62.50 (13.84) | 63.29 (13.73) | ||||
| 3 mo. follow up | 63.56 (15.00) | 62.43 (15.12) | 62.76 (14.56) | 63.23 (15.59) | 1,193 | 0.86 | 4.62* | 0.50 |
| 12 mo. follow up | 63.71 (15.79) | 62.61 (15.42) | 63.27 (15.28) | 63.05 (15.94) | 1,198 | 0.51 | 8.49** | 0.76 |
Note. BMI = Brief Motivational Intervention; CDI = Computer-Delivered Intervention; BST = Booster. Perception of peer drinking reflects perception of typical number of drinks per occasion. N’s are slightly different between follow-ups and between measures, due to missing data on self-administered measures.
†
p<.08.
*
p<.05.
**
p < .01.
***
p < .001