Evaluation of the Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire in diarrheal-predominant irritable bowel syndrome patients

Table 2 Comparison of confirmatory factor model fit statistics

Statistic	Subscales only	Hierarchical	Orthogonal Bi-factor	Oblique Bi-factor	Single factor
χ²	2441.1	2616.9	2254.9	1923.3	3755.9
(df)	(499)	(519)	(496)	(468)	(527)
AIC	2633.1	2768.9	2452.9	2193.3	3891.9
BIC	3075.7	3119.4	2909.3	2815.7	4205.5
GFI	0.8232	0.8088	0.8346	0.8616	0.7378
CFI	0.877	0.8671	0.8889	0.9073	0.7955
RMSEA	0.072	0.074	0.069	0.066	0.091
(95% CI)	(0.070, 0.075)	(0.071, 0.077)	(0.066, 0.072)	(0.063, 0.069)	(0.089, 0.094)
Average Residual	0.0588	0.062	0.053	0.0448	0.0632
% of Residuals ≥ 0.1 or ≤ -0.1	18.7%	21.2%	16.0%	10.5%	20.0%

Note: χ² = Likelihood ratio χ²; df = χ² degrees of freedom; AIC = Akaike’s Information Criterion (smaller is better); BIC = Schwartz’s Bayesian Information Criterion (smaller is better); GFI = Goodness-of-Fit Index (Acceptable fit > 0.9); CFI = Bentler’s Comparative Fit Index (Good fit > 0.9); RMSEA = root-mean-square error of approximation (Very good fit <0.05;Moderate fit between 0.05 and 0.1); CI = confidence interval.

ISSN: 1477-7525