Reliability and validity of an adapted version of the ALPHA environmental questionnaire on physical activity in Spanish youth.

INTRODUCTION Previous studies suggest that the physical environment is associated with youth physical activity levels. OBJECTIVE The present study aimed at assessing the reliability and validity of an adapted version of the ALPHA environmental questionnaire (short version) to adults for application with Spanish youth. METHODS The reliability was evaluated in a sample (n = 190, 80 girls, 14.08 ± 1.38 years) using the Intraclass Correlation Coefficient (ICC) and Weighted kappa. In other sample (n = 140, 61 girls, 13.03 ± 1.40 years) the validity was assessed using the Spearman correlation (rho) for its association with self-reported and objective (accelerometers) physical activity (PA). RESULTS The test-retest reliability showed ICC = 0.69 for the total questionnaire score, ranging from k = 0.42 to 0.77 for individual items. The total score showed significant correlations with PA reported by PACE questionnaire (rho = 0.18, p = 0.040), the Finnish Physical Activity Index (rho = 0.26, p = 0.002) and active commuting for girls (rho = 0.34, p = 0.010), as well as vigorous PA measured by accelerometry (rho = 0.18, p = 0.038). DISCUSSION The adapted version of the ALPHA environmental questionnaire has moderate to good reliability and acceptable validity to assess environmental factors that may influence PA in youth.