Next Previous First Page Method Results Discussion References Appendix

The Efficacy of Rational Emotive Therapy: A Quantitative Review of the Outcome Research. Table 4 shows other study characteristics associated with the sample. The degree of similarity of the therapy to RET was found not to be related to d, for both the treatment and comparison groups. Duration of therapy was found to be significantly related to effect size, in terms of the number of hours and weeks of therapy . ____________________ Insert Table 4 about here ____________________ Table 5 presents the effect size estimates broken down by comparison groups. To facilitate the analysis and understanding of these results a Binomial Effect Size Display (BESD; Rosenthal & Ruben, 1982) was also employed. The BESD displays the change in improvement rate (or success rate, survival rate, etc.) attributable to a certain treatment intervention. In other words, the BESD is the estimated difference in the probabilities of improvement between the treatment and control, or between pre- and post intervention. It is defined as BESD = (.50-r/2) to (.50+r/2), where r is a point biserial correlation. For example, an effect size of d = .872, (r = .40), when expressed as a BESD, shows that the improvement, or improvement rate prior to intervention is 30%, while after the intervention the improvement rate increases to 70%. ____________________ Insert Table 5 about here ____________________ The overall effect size was .949. Using the BESD, 27.2 % of the sample would have demonstrated significant improvement before therapy. Following RET, 72.8 % of the sample demonstrated significant improvement over those subjects not receiving RET. In comparing RET to all other treatment conditions, a one way ANOVA indicated significant differences in effect sizes between the various comparisons (F (6,229) = 9.624, p < .001). A Duncan's Multiple Range test indicated that comparisons with baseline conditions had significantly higher effects sizes than all other comparison groups, except for those comparisons with a waiting list control group. Compared to baseline, the mean effect size was 1.371. Using the BESD indicator, the pretherapy clinical improvement rate was 21.5 %. Following RET intervention the improvement rate was 78.5 %. Comparisons with therapies using CBM or Behavior Therapy demonstrated the lowest mean effect sizes of the sample. A Duncan's Multiple Range test indicated that CBM and Behavior Therapy had significantly lower effect sizes than any of the other treatment conditions.