Measurement invariance across chronic conditions: a systematic review and an empirical investigation of the Health Education Impact Questionnaire (heiQ™)

Table 4 True standardized mean differences (PI _DIFF ) and impact of non-invariant items on latent (ES _SI-PI ; lower triangle) and composite (ES _PI-ALL , ES _PI-RES , upper triangle) mean differences

Disease group		Ortho	Rheu	Asthma	COPD	Cancer
Positive and active engagement in life
Ortho			0.32^a	0.27^a	0.31^a	0.24^a	ES _PI-ALL
Ortho			0.09	0.17	0.06	0.03	ES _PI-RED
Rheu	PI _Diff	0.59		0.08	0.02	0.10	ES _PI-ALL
Rheu	ES _SI-PI	0.27^a		0.14	0.05	^b	ES _PI-RED
Asthma	PI _Diff	0.20	-0.43		0.06	0.02	ES _PI-ALL
Asthma	ES _SI-PI	0.28^a	-0.02		0.09	0.04	ES _PI-RED
COPD	PI _Diff	0.47	-0.13	0.27		0.08	ES _PI-ALL
COPD	ES _SI-PI	0.27^a	-0.13	0.01		0.12	ES _PI-RED
Cancer	PI _Diff	-0.03	-0.64	-0.24	-0.52
	ES _SI-PI	0.28^a	> - 0.01	0.01	> - 0.01
Self-monitoring and insight
Ortho			0.11	0.22^a	0.12	0.10	ES _PI-ALL
Ortho			0.02	0.06	0.02	0.04	ES _PI-RED
Rheu	PI _Diff	0.24		0.32^a	0.22^a	0.21^a	ES _PI-ALL
Rheu	ES _SI-PI	0.08		0.13	0.08	0.10	ES _PI-RED
Asthma	PI _Diff	-0.34	-0.56		0.09	0.13	ES _PI-ALL
Asthma	ES _SI-PI	-0.05	-0.13		0.03	0.02	ES _PI-RED
COPD	PI _Diff	-0.16	-0.38	0.16		0.03	ES _PI-ALL
COPD	ES _SI-PI	-0.03	-0.10	0.03		0.02	ES _PI-RED
Cancer	PI _Diff	-0.31	-0.55	0.04	-0.15
	ES _SI-PI	<0.01	-0.08	0.06	0.02

Notes: Ortho: orthopedic condition; Rheu: rheumatism; PI_Diff: Estimations of latent mean differences in partial invariance models; ES_SI-PI: Difference in latent mean differences between strict and partial invariance models; ES_PI-ALL: Difference between latent mean differences in partial invariance models and composite mean differences using all items of a scale; ES_PI-RED: Difference between latent mean differences in partial invariance models and composite mean differences using only items with pairwise non-invariant parameters; ^arelevant misestimation (ES > |0.2|); ^bno item with DIF between groups.

ISSN: 1477-7525