Establishing the HLS-Q12 short version of the European Health Literacy Survey Questionnaire: latent trait analyses applying Rasch modelling and confirmatory factor analysis

Abstract

BackgroundThe European Health Literacy Survey Questionnaire (HLS-EU-Q47) is widely used in assessing health literacy (HL). There has been some controversy whether the comprehensive HLS-EU-Q47 data, reflecting a conceptual model of four cognitive domains across three health domains (i.e. 12 subscales), fit unidimensional Rasch models. Still, the HLS-EU-Q47 raw score is commonly interpreted as a sufficient statistic. Combining Rasch modelling and confirmatory factor analysis, we reduced the 47 item scale to a parsimonious 12 item scale that meets the assumptions and requirements of objective measurement while offering a clinically feasible HL screening tool. This paper aims at (1) evaluating the psychometric properties of the HLS-EU-Q47 and associated short versions in a large Norwegian sample, and (2) establishing a short version (HLS-Q12) with sufficient psychometric properties.MethodsUsing computer-assisted telephone interviews during November 2014, data were collected from 900 randomly sampled individuals aged 16 and over. The data were analysed using the partial credit parameterization of the unidimensional polytomous Rasch model (PRM) and the ‘between-item’ multidimensional PRM, and by using one-factorial and multi-factorial confirmatory factor analysis (CFA) with categorical variables.ResultsUsing likelihood-ratio tests to compare data-model fit for nested models, we found that the observed HLS-EU-Q47 data were more likely under a 12-dimensional Rasch model than under a three- or a one-dimensional Rasch model. Several of the 12 theoretically defined subscales suffered from low reliability owing to few items. Excluding poorly discriminating items, items displaying differential item functioning and redundant items violating the assumption of local independency, a parsimonious 12-item HLS-Q12 scale is suggested. The HLS-Q12 displayed acceptable fit to the unidimensional Rasch model and achieved acceptable goodness-of-fit indexes using CFA.ConclusionsUnlike the HLS-EU-Q47 data, the parsimonious 12-item version (HLS-Q12) meets the assumptions and the requirements of objective measurement while offering clinically feasible screening without applying advanced psychometric methods on site. To avoid invalid measures of HL using the HLS-EU-Q47, we suggest using the HLS-Q12. Valid measures are particularly important in studies aiming to explain the variance in the latent trait HL, and explore the relation between HL and health outcomes with the purpose of informing policy makers.

Determinants and Consequences of Limited Health Literacy in Polish Society

“…Therefore, a shortened but also validated, the 16-item version has been used in many surveys (HLS-EU-Q16) [5,12,[25][26][27][28][29]. The HLS-EU-Q16 questionnaire has been used not only in direct interviews with respondents [27,29] but also for telephone-based studies [12,26,30] or online surveys [31]. In some studies, the paper-based questionnaire was self-administered by respondents [32].The only previous study of HL on a nationally representative sample of the Polish population was undertaken as part of the HLS-EU project [4] using the HLS-EU-Q47 questionnaire.…”

Describing progression of health literacy skills: Establishing the HLS-Q12 cut-off scores

“…The sample was drawn from the member list of the Norwegian Diabetes Association, who offered a geographically stratified sample that included the members' places of residence. In this paper, we base our analyses on the 12-item short form HLS-Q12 [6,7]. Finbråten et al [6,7] thoroghly describe the sampling procedures and sample characteristics.…”

“…In this paper, we base our analyses on the 12-item short form HLS-Q12 [6,7]. Finbråten et al [6,7] thoroghly describe the sampling procedures and sample characteristics.…”

“…Applying confirmatory factor analyses and Rasch modelling, Finbråten et al [6,7] developed the 12item HLS-Q12 scale from the 47-item HLS-EU-Q47 by deleting items that displayed differential item functioning (DIF; [50]) for available person factors (gender, age and education level), items that displayed unordered response categories or reversed thresholds [51] and redundant items.…”

“…To support the strategy and provide knowledge-based policy and practice M-POHL is firmly committed to the continuing development of their comprehensive and widely used self-reported European Health Literacy Survey questionnaire (HLS-EU-Q47). The questionnaire was applied in a population study in eight European countries in 2011 [1] and later in Asian countries [5] and further European countries, such as Norway in 2014-2015 [6,7]. An accumulated body of corroborating evidence shows that the HLS-EU-Q47 data is not unidimensional [5][6][7][8][9][10][11], which gave rise to a controversy that led to the publication of the HLS-Q12 short form [7].…”