Table 1.
Mean baseline and least squares mean change and treatment difference between pimavanserin and placebo for study outcomes
| Stage 1 | Stage 2 | |||
|---|---|---|---|---|
| Placebo | Pimavanserin | Placebo | Pimavanserin | |
| HAMD anxiety/somatization factor at baseline | N = 152 | N = 51 | N = 29 | N = 29 |
| Baseline mean (SE) | 6.6 (0.18) | 6.9 (0.36) | 6.0 (0.43) | 6.5 (0.49) |
| Change from baseline to week 5 | ||||
| LS mean (SE)a | −2.1 (0.21) | −3.7 (0.36) | −0.6 (0.35) | −0.6 (0.33) |
| 95% CI of LS mean | (−2.5 to −1.7) | (−4.4 to −3.0) | (−1.3 to 0.1) | (−1.3 to 0.0) |
| LS mean (SE) difference (pimavanserin 34 mg-placebo) | −1.5 (0.41) | 0 (0.48) | ||
| 95% CI of difference | (−2.4 to −0.7) | (−1.0 to 1.0) | ||
| P-valueb | 0.0003 | 0.980 | ||
| Effect size (Cohen’s d) | 0.634 | −0.007 | ||
| Overall treatment comparison at week 5 (linear combination test) | ||||
| Weighted difference in LS mean (SE) | −0.8 (0.32) | |||
| 95% CI of weighted difference | (−1.4 to −0.1) | |||
| P-valueb | 0.0166 | |||
| HAMD anxiety/somatization factor ≥7 at baseline | N = 76 | N = 29 | N = 18 | N = 19 |
| Baseline mean (SE) | 8.5 (0.15) | 8.8 (0.28) | 7.1 (0.54) | 7.5 (0.59) |
| Change from baseline to week 5 | ||||
| LS mean (SE)a | −2.8 (0.35) | −5.0 (0.56) | −1.5 (0.49) | −1.3 (0.44) |
| 95% CI of LS mean | (−3.5 to −2.1) | (−6.1 to −3.8) | (−2.5 to −0.5) | (−2.3 to −0.4) |
| LS Mean (SE) difference (pimavanserin 34 mg-placebo) | −2.2 (0.66) | 0.1 (0.66) | ||
| 95% CI of difference | (−3.5 to −0.9) | (−1.2 to 1.5) | ||
| P-valueb | 0.0013 | 0.847 | ||
| Effect size (Cohen’s d) | 0.781 | −0.067 | ||
| Overall treatment comparison at week 5 (linear combination test) | ||||
| Weighted difference in LS mean (SE) | −1.0 (0.47) | |||
| 95% CI of weighted difference | (−2.0 to −0.1) | |||
| P-valueb | 0.027 | |||
| HAMD total score ≥24 and HAMD anxiety/somatization factor ≥7 at baseline | N = 36 | N = 17 | N = 8 | N = 10 |
| Baseline mean (SE) | 27.6 (0.41) | 27.6 (0.70) | 24.0 (1.20) | 22.0 (1.90) |
| Change from baseline to week 5 | ||||
| LS mean (SE)a | −9.3 (1.40) | −17.4 (1.97) | −1.3 (1.68) | −3.7 (1.43) |
| 95% CI of LS mean | (−12.1 to −6.5) | −21.4 to −13.4) | (−4.9 to 2.3) | −6.8 to −0.6) |
| LS mean (SE) difference (pimavanserin 34 mg-placebo) | −8.1 (2.42) | −2.4 (2.22) | ||
| 95% CI of difference | (−13.0 to −3.2) | (−7.2 to 2.3) | ||
| P-valueb | 0.0018 | 0.295 | ||
| Effect size (Cohen’s d) | 1.037 | 0.536 | ||
| Overall treatment comparison at week 5 (linear combination test) | ||||
| Weighted difference in LS mean (SE) | −5.2 (1.64) | |||
| 95% CI of weighted difference | −8.5 to −2.0) | |||
| P-valueb | 0.0014 | |||
ANCOVA, analysis of covariance; CI, confidence interval; HAMD, Hamilton depression rating scale; LS, least squares; SE, standard errors.
a
LS mean from the stage-specific ANCOVA analysis with the change from baseline as the outcome, treatment group as a factor, and the corresponding baseline value as a covariate.
b
Two-sided P-value for treatment difference from the stage-specific ANCOVA analysis.