Assessing psychometric properties and measurement invariance of the Sleep Quality Questionnaire among healthcare students

Table 4 Longitudinal measurement invariance of the SQQ-9 (N = 595)

Hypothesis	χ² (df)	P	Scaled chi-square difference test statistics		CFI	ΔCFI	TLI	ΔTLI	RMSEA (90% CI)	ΔRMSEA
Hypothesis	χ² (df)	P	Δχ² *(Δdf)*	P	CFI	ΔCFI	TLI	ΔTLI	RMSEA (90% CI)	ΔRMSEA
Configural	229.633 (120)	< 0.001			0.990		0.988		0.039 (0.031, 0.047)
Metric	264.618 (145)	< 0.001	34.468 (25)	0.098	0.989	-0.001	0.989	0.001	0.037 (0.030, 0.044)	-0.002
Scalar	318.995 (152)	< 0.001	76.006 (7)	< 0.001	0.985	-0.004	0.985	-0.004	0.043 (0.036, 0.050)	0.006
Strict	369.138 (161)	< 0.001	54.163 (9)	< 0.001	0.981	-0.004	0.982	-0.003	0.047 (0.040, 0.053)	0.004
Threshold	N/A	> 0.050	N/A	> 0.050	≥ 0.950	≤ 0.010	≥ 0.950	≤ 0.010	≤ 0.080	≤ 0.015

SQQ-9 Sleep Quality Questionnaire (item 2 excluded), χ² chi-square, df degrees of freedom, CFI comparative fit index, TLI Tucker-Lewis index, RMSEA root mean square error of approximation, CI confidence interval, Δ change in χ², df, CFI, TLI, and RMSEA, N/A not applicable

ISSN: 2050-7283