Table 3.
Effect of treatment on knee pain induced by painful stimulation before and after fMRI scan
| Statistics | ER-APAP | Placebo | No Treatment | ER-APAP vs Placebo | ER-APAP vs No Treatment | Placebo vs No Treatment |
|---|---|---|---|---|---|---|
| Prescan | ||||||
| LS mean | 0.6* | 0.43* | 0* | 0.12† | 0.59† | 0.48† |
| 95% CI | 0.13 to 1.06‡ | 0.04 to 0.91‡ | −0.5 to 0.5‡ | −0.47 to 0.70§ | −0.08 to 1.26§ | −0.17 to 1.12§ |
| P | 0.014¶ | 0.032¶ | NS¶ | NS‖ | NS‖ | NS‖ |
| Postscan | ||||||
| LS mean | 0.55^ | −0.17^ | −0.34^ | 0.72** | 0.88** | 0.16** |
| 95% CI | −0.3 to 1.39†† | −1.0 to 0.62†† | −1.2 to 0.5†† | −0.16 to 1.6‡‡ | −0.13 to 1.9‡‡ | −0.8 to 1.14‡‡ |
| P | NS§§ | NS§§ | NS§§ | NS¶¶ | NS¶¶ | NS¶¶ |
ANCOVA = analysis of covariance; CI = confidence interval; ER-APAP = extended-release paracetamol; fMRI = functional magnetic resonance imaging; LS = least squares; NRS = numerical rating scale; NS = not significant.
LS mean change in pain intensity after stimulation/before fMRI scan. Change in pain intensity after stimulation/before fMRI scan was calculated for each subject as difference between pain intensity before treatment/after stimulation with pain intensity after treatment, after stimulation, and before fMRI scan.
Between-treatment differences of LS mean change in pain intensity after stimulation but before fMRI scan derived from ANCOVA, with treatment as a fixed effect and subjects as a random effect and period and baseline pain intensity (NRS score at prescreening) as covariates.
95% CI for LS mean change in pain intensity after stimulation/before fMRI scan within each treatment group.
95% CI for between-treatment differences in LS mean change in pain intensity after stimulation/before fMRI scan.
P value associated with t test (H0: LS mean change in pain intensity after stimulation/before fMRI scan = 0) within each treatment group.
P value from multiple treatment comparisons of LS mean change in pain intensity after stimulation/before fMRI scan.
^LS mean change in pain intensity after stimulation/after fMRI scan. Change in pain intensity after stimulation/after fMRI scan was calculated for each subject as difference between pain intensity before treatment/after stimulation with pain intensity after treatment, after stimulation, and after fMRI scan.
Between-treatment difference in LS mean change in pain intensity after stimulation/after fMRI scan derived from ANCOVA, with treatment as a fixed effect and subjects as a random effect. Period and baseline pain intensity (NRS score at prescreening) were used as covariates.
95% CI for LS mean change in pain intensity after stimulation/after fMRI scan within each treatment group.
95% CI for between-treatment differences in LS mean change in pain intensity after stimulation/after fMRI scan.
P value associated with t test (H0: LS mean change in pain intensity after stimulation/after fMRI scan = 0) within each treatment group.
P value from multiple treatment comparisons of LS mean change in pain intensity after stimulation/after fMRI scan.