Table 2.
Randomized controlled trials of online alcohol interventions
| Study | Treatment Group (or Treatment Group 1 if More Than One Group) |
Control Group | |||||||||
| Correction for Alcohol Unitsa | n | Mean (SD) Pre |
Mean (SD) Post | Mean at Follow Up | n | Mean (SD) Pre |
Mean (SD) Post | Mean at Follow Up | Pre-Post Effect Size (d) | Pre-Follow Up Effect Size (d) | |
| Bewick et al [49]b | 0.80 | 138 | b | 9.62 (10.86) | 179 | b | 11.88 (14.9) | 0.02b | |||
| Riper et al [42]c | 1.00 | 130 | 43.7 (21.0) | 28.7d | 131 | 43.5 (22.3) | 40.6d | 0.56 | |||
| Doumas et al [43]c | 1.40 | 46 | 11.42 (9.2) | 6.8 (5.43) | 31 | 9.86 (7.42) | 8.1 (8.27) | 0.33 | |||
| Hustad et al [47] (1) AlcoholEduc,e |
1.40 | 26 | 8.9 (11.62) | 11.0 (15.54) | 24 | 9.28 (12.4) | 18.14 (17.25) | 0.56 | |||
| Hustad et al [47] (2) eCHUGc,e |
1.40 | 30 | 12.4 (14.29) | 10.4 (11.09) | 24 | 9.28 (12.4) | 18.1 (17.25) | 0.81 | |||
| Cunningham et al [41], full samplec | 1.36 | 92 | 18.9 (14.82) | 14.96 (12.38) | 15.1 (12.1) | 93 | 16.18 (13.7) | 15.5 (14.0) | 15.64 (14.0) | 0.23 | 0.23 |
| Cunningham et al [41], problem drinkers only | 1.36 | 35 | 30.6 (17.14) | 20.54 (15.23) | 21.76 (16.2) | 37 | 25.98 (16.3) | 25.02 (16.73) | 24.34 (17.0) | 0.54 | 0.43 |
a The table displays means in 10-gram alcohol units. Calculations use stated drink sizes where available. Where a paper referred only to numbers of drinks, these were adjusted using national “standard drink” sizes [53]. Alcohol units calculated per week unless otherwise stated
b Baseline data presented by Bewick et al [49] is not from the posttreatment sample. The pre-post difference is based on the mean differences and related SDs from baseline to posttreatment. Analyses in that study were based on transformed data.
c Means were calculated using identified comparisons.
d Post SDs were not reported.
e Units of alcohol reported are per month.