Table 5

Between and within group comparisons at weeks 8 and 12
WEEK 8
Study parameter A = Active product C = Control product A vs C
n Mean (week 12–baseline) (SD) p value* (change from baseline) n Mean (week 12–baseline) (SD) p value* (change from baseline) p value**
IBS-SSS 50 −58.30 (84.96) <0.001 40 −58.33 (73.37) <0.001 0.589
Birmingham IBS symptom scale
Constipation 52 13.78 (24.47) <0.001 41 17.24 (22.61) <0.001 0.302
Diarrhoea 4.25 (13.78) 0.210 2.15 (7.71) 0.064 0.907
Pain 11.28 (18.88) <0.001 13.66 (16.80) <0.001 0.257
Total score 8.71 (13.09) <0.001 9.44 (9.75) <0.001 0.265
IBS specific symptoms
Pain 53 −0.58 (1.24) 0.012 41 −0.66 (1.43) 0.002 0.292
Bloating 52 −0.80 (1.44) 0.005 −0.85 (1.26) <0.001 0.408
Flatulence 53 −0.54 (1.28) 0.002 40 −0.50 (1.08) 0.004 0.864
Composite score 52 −1.95 (3.43) 0.003 −1.96 (3.17) <0.001 0.374
Stool frequency 346 0.07 (0.95) 0.303 276 0.10 (0.05) 0.141 0.828
Stool consistency 290 0.18 (1.17) 0.042 218 0.50 (1.23) 0.001 0.098
Bowel movement difficulty 291 −0.43 (1.01) <0.001 224 −0.40 (0.78) <0.001 0.623
IBS Quality of life
Dysphoria 53 14.66 (19.87) <0.001 41 9.29 (13.95) <0.001 0.508
Activity interference 8.20 (14.74) 0.001 6.05 (12.99) 0.001 0.924
Body image 11.95 (15.98) <0.001 8.54 (13.46) <0.001 0.735
Health worry 13.29 (17.81) <0.001 7.62 (15.19) 0.002 0.428
Food avoidance 10.06 (17.63) <0.001 5.49 (17.84) 0.039 0.372
Social reaction 10.85 (16.18) <0.001 6.71 (12.21) <0.001 0.462
Sexual 8.41 (18.31) 0.006 7.05 (16.92) 0.005 0.554
Relationship 7.23 (18.64) 0.015 7.01 (9.88) <0.001 0.635
Total score 10.95 (13.14) <0.001 7.52 (10.22) <0.001 0.483
WEEK 12
IBS-SSS 43 −61.02 (75.78) <0.001 33 −97.24 (90.17) <0.001 0.028
Birmingham IBS symptom scale
Constipation 48 6.65 (22.56) 0.039 35 17.52 (23.60) <0.001 0.011
Diarrhoea 3.27 (11.17) 0.048 2.43 (10.60) 0.133 0.889
Pain 10.28 (14.09) <0.001 15.24 (17.38) <0.001 <0.107
Total score 6.07 (9.62) <0.001 10.10 (10.78) <0.001 <0.022
IBS specific symptoms
Pain 48 −0.59 (1.24) 0.002 34 −1.04 (1.33) <0.001 0.016
Bloating 48 −0.58 (1.39) 0.005 −1.35 (1.21) <0.001 0.006
Flatulence 48 −0.64 (1.04) 0.001 −0.76 (1.23) <0.001 0.383
Composite score 48 −1.81 (3.03) <0.001 −3.16 (3.05) <0.001 0.011
Stool frequency 311 −0.07 (0.75) 0.186 224 0.07 (0.82) 0.464 0.211
Stool consistency 247 0.26 (1.22) 0.045 181 0.31 (0.99) 0.012 0.784
Bowel movement difficulty 246 −0.35 (0.99) <0.001 180 −0.36 (0.86) <0.001 0.329
IBS Quality of life
Dysphoria 48 13.61 (20.12) <0.001 34 10.83 (10.68) <0.001 0.933
Activity interference 8.47 (12.31) <0.001 34 7.09 (8.73) <0.001 0.806
Body image 11.33 (14.16) <0.001 34 8.27 (14.08) 0.005 0.857
Health worry 14.15 (21.01) <0.001 34 9.07 (13.19) <0.001 0.634
Food avoidance 8.16 (20.45) 0.008 34 8.58 (13.37) <0.001 0.687
Social reaction 9.64 (17.15) <0.001 34 9.38 (8.74) <0.001 0.660
Sexual 8.07 (21.34) 0.031 32 10.55 (16.53) <0.001 0.382
Relationship 7.03 (15.81) 0.002 34 5.51 (9.22) <0.001 0.751
Total score 10.43 (12.92) <0.001 34 8.83 (6.12) <0.001 0.810

*ANCOVA with centre as a random effect, baseline as a covariate and product as a fixed effect.

**Ordinal logistic regression with centre and product fixed effects.

Stool frequency, consistency and bowel movement difficulty were recorded daily and therefore n represents the number of data items (days) included in analysis for these items.

Roberts et al.

Roberts et al. BMC Gastroenterology 2013 13:45   doi:10.1186/1471-230X-13-45

Open Data