Marianne Welmers

Chapter 2 58 was very heterogeneous with regard to problem type and treatment model. As a result, several categories for these variables were represented by only one or two studies. Thus, the fact that the moderating effect of problem type and treatment model failed to reach significance might partly be explained by a lack of statistical power. Nevertheless, this finding underlines the importance of training and supervision for therapists in alliance building techniques in addition to training and supervision of specific treatment model techniques. In contrast to our expectations, both gender and ethnicity of clients did not moderate the association between level of alliance and outcome. With regard to gender, two previous studies on alliance and outcome in family therapy and couple therapy demonstrated that for male adults other aspects of alliance are important in relation to treatment outcome compared to females (Johnson, Wright, & Ketring, 2002), and that the correlation between alliance and outcome might be stronger when males have a higher level of alliance with their therapist than their female partners (Symonds & Horvath, 2004). With regard to ethnicity, one included study on split alliance and outcome shows a stronger correlation between alliance and outcome for Hispanic families compared toAnglo-American families (Flicker et al., 2008). It should be noted, however, that most of the studies included in the present study made no distinction between alliance-outcome correlations for boys and girls, or father and mothers, or between different ethnical groups. Thus, there was no variance between effect sizes within studies with regard to gender or ethnicity. We did, however, find a significant moderating effect for percentage of male adults in the association between alliance change scores and treatment outcome, demonstrating stronger correlations in samples with lessmale adults. Thismight indicate that for fathers, the process of alliance improvement is more predictive of treatment outcome than for mothers. For outcome measures characteristics no moderating effects were found in any of the investigated associations in contrast to findings of previous meta-analyses on alliance and outcome in youth or adult psychotherapy (Horvath et al., 2011; McLeod, 2011; Shirk & Karver, 2003). This indicates that alliance is a significant small predictor of treatment outcome in family-involved treatment, regardless of how and when outcome ismeasured. Lastly, there was nomoderating effect for study quality in the associations between level of alliance and outcome, and alliance change scores and outcome, although there was a trend toward significance in the first association indicating stronger correlations in studies of less quality. This moderating effect was significant in the association between split alliances and outcome.