Table 2. Tests of Intercept Differences, Overall Slope Effects, and Slope Differences in Random Intercept Random Coefficient Models of Primary and Secondary Treatment Outcomes During Treatment .
| Outcome and Effect | Effect Typea | Estimate (95% CI)b | P Values |
|---|---|---|---|
| Primary Outcome | |||
| BDD symptom severity (BDD-YBOCS) | |||
| Site | Intercept difference | 1.81 (−0.11 to 3.73) | .06 |
| Time | Overall changec | −15.37 (−17.36 to −13.38) | <.001 |
| Time × treatment | Effect of treatment overallc | −6.46 (−10.43 to −2.49) | .002 |
| Time × site | Effect of site overallc | −4.57 (−8.55 to −0.60) | .02 |
| Time × treatment × site | Site difference in treatment effectc | 4.58 (0.62 to 8.55) | .02 |
| Secondary Outcomes | |||
| Insight (BABS) | |||
| Site | Intercept difference | −0.02 (−1.75 to 1.70) | .98 |
| Time | Overall changec | −7.91 (−9.19 to −6.64) | <.001 |
| Time × treatment | Effect of treatment overallc | −2.07 (−4.55 to 0.41) | .10 |
| Time × site | Effect of site overallc | −1.18 (−3.73 to 1.37) | .36 |
| Time × treatment × site | Site difference in treatment effectc | 2.23 (−0.25 to 4.71) | .08 |
| Depression severity (BDI-II) | |||
| Site | Intercept difference | 0.42 (−4.25 to 5.08) | .86 |
| Time | Overall changec | −8.10 (−10.43 to −5.78) | <.001 |
| Time × treatment | Effect of treatment overallc | −4.48 (−8.97 to 0.00) | .05 |
| Time × site | Effect of site overallc | −0.10 (−4.75 to 4.56) | .97 |
| Time × treatment × site | Site difference in treatment effectc | 2.25 (−2.24 to 6.73) | .32 |
| Functional impairment (SDS) | |||
| Site | Intercept difference | 0.8 (−1.29 to 2.90) | .45 |
| Time | Overall changec | −8.07 (−9.80 to −6.34) | <.001 |
| Time × treatment | Effect of treatment overallc | −1.75 (−5.10 to 1.59) | .30 |
| Time × site | Effect of site overallc | −1.71 (−5.18 to 1.75) | .33 |
| Time × treatment × site | Site difference in treatment effectc | 2.08 (−1.27 to 5.42) | .22 |
| Quality of life (QLESQ-SF), % | |||
| Site | Intercept difference | 5.43 (−0.16 to 11.03) | .06 |
| Time | Overall changec | 16.30 (12.82 to 19.79) | <.01 |
| Time × treatment | Effect of treatment overallc | 7.20 (0.35 to 14.05) | .04 |
| Time × site | Effect of site overallc | 1.48 (−5.49 to 8.46) | .67 |
| Time × treatment × site | Site difference in treatment effectc | −5.58 (−12.44 to 1.27) | .11 |
Abbreviations: BABS, Brown Assessment of Beliefs Scale (total score range: 0-24, with higher scores indicating poorer insight about symptoms); BDD, body dysmorphic disorder; BDD-YBOCS, Yale-Brown Obsessive Compulsive Scale Modified for BDD (score range: 0-48, with higher scores indicating higher symptom severity); BDI-II, Beck Depression Inventory–Second Edition (total score range: 0-63, with higher scores indicating greater depression severity); QLESQ-SF, Quality of Life Enjoyment and Satisfaction Questionnaire-Short form (score range: 0%-100%, with higher scores indicating greater quality of life); SDS, Sheehan Disability Scale global functioning score (score range: 0-30, with higher scores indicating greater functional impairment).
Effect type refers to the model parameters tested in the latent growth curve models, where site tests are differences in mean intercepts at week 0, time tests are the overall mean slope over the time period indicated, and time × treatment, time × site, and time × treatment × site test are mean slope differences between treatments, sites, or treatments within each site.
Units are scale points on each scale except for the QLESQ-SF, where the units are percentage score points.
Change is over 24 weeks of assessment during treatment. Any effect where P < .05 is a significant effect that is explained in the Statistical Analysis subsection.