Table 3.
Variable | Standard care | CM | Significance test value (df), p-value | Effect size Cohen’s d |
---|---|---|---|---|
Week 1 | n = 89 | n = 87 | ||
Group cohesion | 114.3 ± 17.0 | 119.5 ± 15.1 | t (174) = 2.11, p < .04 | .32 |
Helping alliance | 88.7 ± 13.5 | 94.4 ± 12.2 | t (175) = 2.93, p < .01 | .44 |
Month 1 | n = 73 | n = 84 | ||
Group cohesion | 113.5 ± 14.6 | 120.6 ± 17.5 | t (155) = 2.73, p < .01 | .44 |
Helping alliance | 87.3 ± 17.3 | 96.7 ± 13.0 | t (149) = 3.78, p < .001 | .61 |
Month 2 | n = 34 | n = 42 | ||
Group cohesion | 114.4 ± 18.1 | 118.7 ± 17.3 | t (73) = 1.04, p = .30 | .24 |
Helping alliance | 89.5 ± 13.0 | 95.4 ± 15.1 | t (71) = 1.77, p = .08 | .42 |
Note: Sample sizes are based on patients remaining in group treatment session at each time point and completing the questionnaires; degrees of freedom differ at time points based on some incomplete assessments. CM=contingency management