Latent variable mixture models to test for differential item functioning: a population-based analysis

Table 2 Model fit statistics and class proportions for latent variable mixture models on the SF-36 physical functioning and mental health sub-scale items

# Classes	# Par	BIC	VLMR p-value	BLRT p-value	Entropy	Class proportions^a
# Classes	# Par	BIC	VLMR p-value	BLRT p-value	Entropy	Class 1	Class 2	Class 3	Class 4
Physical Functioning
1	28	102,298.56				1.00
2	57	100,569.46	<0.0001	<0.0001	0.55	0.61 (0.68)	0.39 (0.32)
3	86	100,083.64	0.0007	<0.0001	0.64	0.59 (0.64)	0.24 (0.22)	0.17 (0.14)
4	115	99,806.68	NA	NA	0.60	0.51 (0.55)	0.22 (0.19)	0.17 (0.16)	0.10 (0.10)
Mental Health
1	20	95,536.81				1.00
2	41	94,631.65	<0.0001	<0.0001	0.40	0.69 (0.78)	0.31 (0.22)
3	62	94,363.51	NA	NA	0.44	0.25 (0.20)	0.37 (0.40)	0.38 (0.40)

Bold values indicate the model that was selected for further analysis. # Par = number of parameters. BIC Bayesian information criterion. VLMR Vuong-Lo-Mendell-Rubin likelihood ratio test. BLRT Bootstrap likelihood ratio test. NA Not Applicable
^aClassification of individuals based on their most likely latent class is shown in parentheses

ISSN: 1477-7525