Validation of the Headache Impact Test (HIT-6) in patients with chronic migraine

Table 2 Standardized factor loadings from confirmatory factor analysis ^*

HIT-6 item		Study 1		Study 2
		(n = 672)		(n = 702^a)
		Factor loading	Standard error	Factor loading	Standard error
A^b	Pain Severe When Headache	0.652	(0.032)	0.740	(0.025)
B	Limit Ability to Do Daily Acts	0.770	(0.023)	0.797	(0.020)
C	Wish Could Lie Down	0.536	(0.032)	0.658	(0.028)
D	Too Tired to Do Work or Daily Acts	0.785	(0.022)	0.796	(0.021)
E	Feel Fed Up/Irritated Because of Headache	0.533	(0.033)	0.554	(0.031)
F	Limit Ability to Concentrate	0.751	(0.027)	0.744	(0.024)

^aOnly includes participants with complete item level HIT-6 data.
^bFactor loading fixed to one for identification purposes.
RMSEA = 0.086; WRMR = 1.263; CFI/TLI = 0.976/0.978.
CFI = comparative fit index; RMSEA = root mean square error of approximation; TLI = Tucker-Lewis Index; WRMR = weighted root mean square residual.
^*Configural Invariance Model at Baseline.

ISSN: 1477-7525