Symptom severity
The ANCOVA indicated no significant difference between OLP and TAU, although there was a non-significant trend pointing to somewhat more symptom improvement in the OLP group (adj. M = 0.93; SE = 0.11) than in the TAU group (adj. M = 1.19; SE = 0.10),F (1, 71) = 3.280, p = .074, ɳ²p = .044. According to a sensitivity power analysis, the given sample size would have been sufficient to uncover a medium to large effect (f = .330) for this analysis, but the actually observed effect size for symptom severity was considerably lower (f = .215). Thus, the power was insufficient to unveil significant effects in this analysis. The reduction of symptoms in the two groups is depicted in Figure 3a and the corresponding descriptive values are presented in Table 2. Symptom severity at baseline was not significantly related to T2 severity,F (1, 71) = 3.368, p = .071, ɳ²p = .045.
Insert Figure 3 here.