Developing an Instrument for Measuring Health Literacy among School-aged Children

Abstract

Health literacy (HL) is an important determinant of health and health behaviours. The aim of this research was to develop a brief, comprehensive, and theory-based instrument for the measurement of subjective HL among school-aged children. A further aim was to examine the cross-national measurement invariance of this instrument in four European countries, i.e. Finland, Poland, Slovakia, and Belgium. The developmental process of the instrument was systematic, iterative, and validity- and reliability-driven. It involved 1) definition and elaboration of the construct, 2) choice of measurement method, 3) item generation, 4) a pilot study (N=401) including test-retest (N=117), and 5) field-testing, including construction of a brief instrument (N= 3853), and examination of the instrument’s international applicability (N=1468). All the samples were taken from pupils aged 13 and 15. Initially, 65 items were generated, of which 32 items were selected for the pilot study. After item reduction, the instrument contained 16 items. The test-retest showed high stability. For the field testing phase, a brief, 10-item instrument was constructed, referred to as Health Literacy for School-aged Children (HLSAC). The instrument, which exhibited a high Cronbach alpha (.93), and adequate fit with the data, included two items from each of five predetermined theoretical components (theoretical knowledge, practical knowledge, individual critical thinking, self-awareness, citizenship). In a cross-national measurement invariance examination, configural and metric invariance was established, but scalar invariance did not hold. Nevertheless, the HLSAC instrument’s internal consistency was high (α=.80–.90) and the fit with the data was adequate in each country. A comparison of health literacy mean values showed significant mean value differences between countries and age groups. Measurement of HL via reliable and valid instruments creates a basis for trustworthy assessment of HL levels and appropriate interventions. The HLSAC instrument is suitable for large-scale studies, and for use with children and adolescents. It constitutes a promising tool for subjective HL comparisons in the international context.