The factor structure of the Turkish version of the Revised Illness Perception Questionnaire (IPQ-R) in patients with diabetes and cardiovascular disease

Table 2 Goodness-of-fit indices for the original and revised models of the Turkish IPQ-R part II (n = 302)

Model	χ ²(df)	Δχ²(Δdf)	RMSEA (90%-CI)	SRMR	TLI	CFI	AIC
Model 1 (M1): Original (38 items)	2396.73		0.075	0.109	0.765	0.785	18177.43
	(644)*		(0.070-0.079)	0.109	0.765	0.785	18177.43
Model 2a (M2a): Modified (34 items)	1479.46	M1-M2a:	0.059	0.083	0.864	0.877	15404.43
	(506)*	917.27 (138)*	(0.054-0.064)	0.083	0.864	0.877	15404.43
Model 2b (M2b): Modified (34 items, 2 error covariances)	1261.09	M2a-M2b:	0.050	0.079	0.901	0.911	15189.58
	(504)*	218.37 (2)*	(0.045-0.056)	0.079	0.901	0.911	15189.58
Model 2c (M2c): Modified (34 items, 2 error covariances, item 6 respecified)	1150.39	M2b-M2c:	0.045	0.067	0.921	0.929	15079.40
	(504)*	110.70 (0)	(0.039-0.050)

Note. χ ² (df): chi-square test of model fit and degrees of freedom; RMSEA (90%-CI): root mean square error of approximation and 90%-confidence intervals; SRMR: standardized root mean square residual; CFI: comparative fit index; TLI: Tucker-Lewis index: AIC: Akaike Information Criterion; *p < 0.001.

ISSN: 1471-2458