Table 3

Treatment outcomes

InterventionComparisonDifference (95% CI)Effect size (Cohen’s D)p Value*
(n=29)(n=29)
Number of foods restricted13.6±5.912.7±6.00.58
4 weeks—primary endpoint(n=27)(n=29)
  GIS1.9±1.21.1±1.50.86
(0.05 to 1.67)
0.550.04†/0.04†
  AR0.6±0.50.5±0.50.15
(−0.14 to 0.43)
0.270.31/0.35
  SSS reduction121±9760±10161.78
(4.43  to 119.14)
0.560.04†/0.05†
  QOL improvement17±1918±150.45
(−7.98 to 8.87)
0.030.92/0.88
8 weeks(n=26)(n=29)
  GIS1.8±1.60.6±1.71.22
(0.22 to 2.22)
0.630.02†/0.04†
  AR0.5±0.50.3±0.50.19
(−0.11 to 0.49)
0.340.22/0.26
  SSS reduction116±10450±10266.42
(5.75 to 127.09)
0.570.03†/0.05†
  QOL improvement19.3±18.515.2±17.6−4.12
(−14.46 to 6.22)
0.220.43/0.30
  • 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.