Treatment outcomes
Intervention | Comparison | Difference (95% CI) | Effect size (Cohen’s D) | p Value* | |
(n=29) | (n=29) | ||||
Number of foods restricted | 13.6±5.9 | 12.7±6.0 | 0.58 | ||
4 weeks—primary endpoint | (n=27) | (n=29) | |||
GIS | 1.9±1.2 | 1.1±1.5 | 0.86 (0.05 to 1.67) | 0.55 | 0.04†/0.04† |
AR | 0.6±0.5 | 0.5±0.5 | 0.15 (−0.14 to 0.43) | 0.27 | 0.31/0.35 |
SSS reduction | 121±97 | 60±101 | 61.78 (4.43 to 119.14) | 0.56 | 0.04†/0.05† |
QOL improvement | 17±19 | 18±15 | 0.45 (−7.98 to 8.87) | 0.03 | 0.92/0.88 |
8 weeks | (n=26) | (n=29) | |||
GIS | 1.8±1.6 | 0.6±1.7 | 1.22 (0.22 to 2.22) | 0.63 | 0.02†/0.04† |
AR | 0.5±0.5 | 0.3±0.5 | 0.19 (−0.11 to 0.49) | 0.34 | 0.22/0.26 |
SSS reduction | 116±104 | 50±102 | 66.42 (5.75 to 127.09) | 0.57 | 0.03†/0.05† |
QOL improvement | 19.3±18.5 | 15.2±17.6 | −4.12 (−14.46 to 6.22) | 0.22 | 0.43/0.30 |
All values are means ±SD, unless otherwise noted. Changes between baseline and the week 4/week 8 time points were computed for all outcomes and tested for whether the mean change observed in the intervention and comparison groups was significantly different (α=0.05) for each measure using independent t-tests. The distributions of changes across time were also tested for equality in the intervention and comparison groups using Wilcoxon rank-sum tests.
*p Values are from independent t-tests and Wilcoxon rank-sum tests.
†Statistically significant at α=0.05.
AR, IBS Adequate Relief Scale; GIS, IBS Global Improvement Scale; IBS, irritable bowel syndrome; QOL, IBS Quality of Life Questionnaire; SSS, IBS Symptom Severity Scale.