Abstract
BACKGROUND: Health Literacy (HL) has become popular in research for its potential in reducing health inequalities. HL is shaped by personal and situational factors, both having particular implications for migrant populations. This study adapted and validated the HLS19-Q12 in migrant and general populations of Finland using two large-scale population studies. We investigated methodological choices to ensure quality of HL measurement and monitoring across population groups. Finally, we examined the association between HL and socioeconomic, health- and migration-related factors in the general and migrant populations of Finland. METHODS: We implemented the Nominal Categories Model (NCM) to empirically evaluate modeling assumptions, studied response functioning and measurement equivalence according to nativity in several language groups, including Finnish and English native (n=3673, n=379) and non-native (n=2077, n=1402) speakers, Russian native speakers (n=926). Methodological effects of opt-out and response format were investigated in the three language versions. Finally, we examined concurrent validity according to socioeconomic (i.e. sex, age, educational attainment, economic activity, economic deprivation, migrant-origin), health- (i.e. self-rated health, chronic disease, health-care use, smoking, obesity, cardiovascular disease risk score) and migration-related factors (i.e. length of residence, language proficiency, language barrier in healthcare) in the general and migrant populations under examination. RESULTS: Cronbach's alpha ranged from .93 to .96 and the u index indicated unidimensionality. Test information functions indicated the scale was most informative at low and medium levels of the trait continuum. The NCM showed acceptable fit and revealed expected ordering of Likert response categories, while the opt-out category showed inconsistencies. We found evidence of unbiased functioning of HLS19-Q12 respecting English and Finnish language nativity, and no evidence of acquiescence effects. Associations between HL and criterion factors were in line with expectations. CONCLUSIONS: This study introduced the Finnish version of HLS19-Q12 and approached valid and reliable HL monitoring as a key element within the field of social determinants of health. This study provided novel insights on HL while replicating findings reported in the literature. We provide specific recommendations for valid monitoring of HL and ponder over culturally and linguistically responsive policy making, in accordance with the Health in All Polices approach.