Validation of the brief instrument “Health Literacy for School-Aged Children” (HLSAC) among Norwegian adolescents

Health literacy (HL) has been identified as an important and modifiable determinant of health. To succeed in promoting HL, it is crucial to evaluate interventions addressing HL using validated instruments. However, HL measurement is an under-researched area among adolescents. The Health Literacy for School-Aged Children (HLSAC) scale is developed in Finland to measure the subjective HL levels of school-aged children. The HLSAC has been used and validated across Europe. No validated instrument for measuring HL among Norwegian adolescents has been identified. Therefore, the aim of this study was to assess the psychometric properties of the HLSAC among Norwegian adolescents in upper secondary schools. Cross-sectional data were collected in 2017 from 1 054 adolescents with a response rate of 93.5%. The participants were students aged 16–21 (mean = 17.3) years from four upper secondary schools in an urban area in Mid-Norway. Confirmatory factor analysis (CFA) was utilized to investigate the underlying dimensionality of the data together with composite reliability based on Raykov’s reliability coefficient and certain aspects of construct validity. The original ten-item one-dimensional version of the HLSAC revealed a poor fit. A one-dimensional version including six of the original ten items presented the best fit to our data, demonstrating good reliability and construct validity. This validation study suggests a one-dimensional solution of the HLSAC scale including six of the original ten items, i.e., the HLSAC-6 as a statistical valid and reliable measure for HL among adolescents in upper secondary schools. However, the modifications of the instrument indicate the need for further investigation of the HLSAC in this age group, i.e. by conducting cognitive interviews and focus-group discussions on the concept of HL among adolescents. Testing the wording of the HLSAC prior to additional psychometric evaluations of both the original HLSAC and the suggested HLSAC-6 is recommended. Finally, developing more age-appropriate items for the measurement of HL in this age-group is suggested.