Table 1.

Pain Measures.

Measure	No Placebo (mean +/− 1 SD)	Placebo (mean +/− 1 SD)	Wilcoxon W testing (Wilcoxon W, p value)
Pain Sensitivity	1.29 +/− 1	0.80 +/− 0.76	W74 = −2.1, p = 0.03
MPQ Sensory Pain	16 +/− 7	14 +/− 8	W74 = −1.5, p > 0.10
MPQ Affective Pain	2 +/− 2	1 +/− 2	W74 = −1.8, p = 0.07

Shown in the table are pain measures recorded from the pain challenge and obtained separately for each pre-treatment intervention (e.g., no intervention, placebo intervention). These measures include Pain sensitivity, the average pain intensity measure acquired during the 20 min sustained pain challenge over the volume of hypertonic saline (ml) needed to maintain a constant level of pain over time 47 and the McGill Pain Questionnaire scores which include Sensory and Affective pain scores. All measures were completed following the pain challenge on each of 2 days, the day without placebo pre-treatment and the day with placebo pre-treatment. Here the mean values (+/−1 SD) for each measure are reported in column 2 (no placebo) and column 3 (placebo) of the table. Repeated measures testing (using Wilcoxon W) compared means for each measure on the day of placebo pre-treatment with the respective means on the day with no placebo pre-treatment. Results (Wilcoxon W and un-corrected p value of significance) are reported in column 4. Significance was set to p < 0.05 to control for a type 1 error. Results indicated that placebo significantly reduced Pain Sensitivity and MPQ Affective Pain (marginal significance), but not MPQ Sensory Pain scores.