Developing the HLS19-YP12 for measuring health literacy in young people: a latent trait analysis using Rasch modelling and confirmatory factor analysis

Table 4 Overall data-model fit, reliability, and unidimensionality by applying Rasch modelling of the 12-item short scales

	HLS₁₉-YP12	HLS₁₉-Q12	HLS₁₉-SF12	HLS₁₉-Q12-NO
	Present study	HLS₁₉ Consortium (2021) [19]	Duong et al. (2019) [23]	Finbråten et al. (2018) [21]
Unidimensionality t-tests (CI)^RUMM
Number significant tests	16	27	34	17
Out of:	415	413	414	414
Dim(%)	3.86%	6.54%	8.21%	4.11%
Proportion lower 95% CI	1.8%	4.4%	6.1%	2.0%
Chi-square interaction^RUMM
Total item chi-square	49.54	72.11	56.72	61.17
df	48	48	48	48
Probability	0.41	0.01 ^a	0.18	0.10
Mean (SD) in logits^RUMM
Item fit residual	0.12 (1.01)	-0.01 (1.08)	0.17 (1.07)	0.04 (1.08)
Person fit residual	-0.40 (1.46)	-0.41 (1.40)	-0.36 (1.31)	-0.36 (1.34)
Mean person location in logits^RUMM	1.035	1.155	1.141	1.084
Reliability
Omega (by Excel-based tool)^Mplus	0.86	0.85	0.84	0.84
PSI based on PMLE^RUMM	0.82	0.81	0.81	0.79
PSR (MMLE/WLE)^CQ	0.829/0.827	0.816/0.815	0.812/0.809	0.809/0.808
Log-likelihoods^CQ
Deviance (ep)	9,659 (37)	9,666 (37)	9,679 (37)	9,772 (37)
AIC (ep)	9,733 (37)	9,740 (37)	9,753 (37)	9,846 (37)

df Degree of freedom, SD Standard deviation, SE Standard error, Omega Internal consistency reliability, PSI Person separation index, PSR Person separation reliability, PMLE Pairwise maximum likelihood estimate, MMLE Marginal maximum likelihood estimate, WLE Warm's mean likelihood estimate, Deviance Deviance statistics, ep Total number of estimated parameters, AIC Akaike Information Criterion, RUMM RUMM2030 software, CQ/ConQuest ConQuest 5 software, Mplus Version 8.6
^a total item chi-square is significant at 5%-level indicating significant deviation between the observed data and what was expected from the Rasch model; dim(%): proportion of individuals with significantly different person-location estimates (below 5% confirms unidimensionality); proportion lower 95% CI: lower than 5% confirms acceptable unidimensionality

ISSN: 1472-6963