Table 1.
Means (and Standard Deviations) of Participants and Peers
| Outcome variable | Participant
|
Effect sizes
|
Peer
|
Effect sizes
|
||||
|---|---|---|---|---|---|---|---|---|
| Baseline | 1 month | dWG | dBG | Baseline | 1 month | dWG | dBG | |
| Drinks per occasion (past 30 days) | ||||||||
| IMI | 5.82 (2.73) | 5.02 (3.65) | .49 | .18 | 5.71 (2.92) | 5.33 (2.25) | .29 | .60 |
| PMI | 6.23 (4.07) | 4.57 (3.96) | .28 | 4.88 (1.98) | 5.19 (3.03) | .29 | ||
| No. of heavy drinking days (past 30 days) | ||||||||
| IMI | 7.28 (5.92) | 5.50*(5.46) | .58 | .01 | 4.41 (5.03) | 5.06* (4.85) | .12 | .36 |
| PMI | 7.00 (5.11) | 3.00* (3.13) | .58 | 5.06 (6.19) | 4.35* (5.58) | .22 | ||
| No. of drinking days (past 30 days) | ||||||||
| IMI | 10.39 (23.19) | 9.06* (7.28) | .22 | .70 | 7.35 (5.66) | 7.00* (5.37) | .16 | .04 |
| PMI | 9.16 (5.63) | 4.50* (3.37) | .49 | 7.46 (7.40) | 7.35* (6.08) | .14 | ||
| YAAPST severity (past year) | ||||||||
| IMI | 36.22 (23.19) | 38.93 (23.57) | .22 | .69 | 25.94 (22.06) | 24.75 (22.29) | .05 | .20 |
| PMI | 45.83 (21.29) | 35.25 (21.49) | .52 | 30.20 (23.16) | 30.57 (21.28) | .17 | ||
Note. dWG = within-group effect sizes; dBG = between-group effect sizes; IMI = individual motivational intervention (nbaseline = 18; n1 mo. = 16); PMI = peer-enhanced motivational intervention (nbaseline = 18; n1 mo. = 12); YAAPST = Young Adults Alcohol Problem Screening Test.
*
p < .01.