Irritable bowel syndrome-specific health-related quality of life instrument: development and psychometric evaluation

Table 4 Known-groups validity according to IBS severity classification

	Classification of IBS severity			F	Post-hoc test	Effect size (η ²)
	Mild	Moderate	Severe
	(n = 101)	(n = 115)	(n = 45)
	Mean ± SD	Mean ± SD	Mean ± SD
Total	2.97 ± 0.70	2.22 ± 0.83	1.81 ± 0.90	41.79^a*	Mild>Moderate, Severe^b	0.24
F1	2.42 ± 0.90	1.57 ± 0.94	1.22 ± 0.97	34.49*	Mild>Moderate>Severe^c	0.21
F2	3.11 ± 0.80	2.28 ± 1.00	1.71 ± 0.94	46.84^a*	Mild>Moderate, Severe^b	0.25
F3	3.14 ± 1.03	2.49 ± 1.27	2.15 ± 1.31	14.22^a*	Mild>Moderate, Severe^b	0.10
F4	3.20 ± 0.83	2.54 ± 1.13	2.17 ± 1.16	21.04^a*	Mild>Moderate>Severe^b	0.13

Factor 1, bowel function; Factor 2, emotions; Factor 3, concerns about social activity; Factor 4, consideration of foods
^aWelch test; ^bGames-Howell test; ^cScheffé’s test
*p < 0.001

ISSN: 1477-7525