OBJECTIVES: Better assessment of the reliability of the physical activity and sedentary behaviour items across countries in all WHO regions is highly needed. The aim of the study was to examine the test-retest reliability of selected physical activity and sedentary behaviour items of the HBSC questionnaire in Czech, Slovak and Polish adolescents. METHODS: We obtained data from 693 Czech, Slovak and Polish (50.9% boys) primary school pupils, grades five (mean age = 11.08; SD = 0.45) and nine (mean age = 15.12; SD = 0.45), who participated in a test-retest study in 2013. We used the single measures of Intraclass Correlation Coefficients (ICC) and Cohen's Kappa statistic to estimate the test-retest reliability of all selected items within the sample and stratified by gender, age group and country. RESULTS: Both physical activity items (VPA and MVPA) and most of the sedentary behaviour items showed moderate agreement (ICC 0.41-0.60) and a similarly moderate correlation (Cohen's Kappa 0.3-0.5) after dichotomization. CONCLUSIONS: The physical activity and sedentary behaviour items of the HBSC questionnaire seem to be at the borderline of reliability to be used in adolescents.

Faculty of Medicine Health Psychology Unit Institute of Public Health P J Safarik University in Kosice Tr SNP 1 Košice 040 66 Slovak Republic