Schroder, HelmutSubirana, IsaacWarnberg, JuliaMedrano, MaríaGonzalez-Gross, MarcelaGusi, NarcisAznar, SusanaAlcaraz, Pedro EGonzalez-Valeiro, Miguel ASerra-Majem, LluisTerrados, NicolasTur, Josep ASegu, MartaHoms, ClaraGarcia-Alvarez, AliciaBenavente-Marin, Juan CBaron-Lopez, F. JavierLabayen, IdoiaGarcia Zapico, AugustoSanchez-Gomez, JesusJimenez-Zazo, FabioMarin-Cascales, ElenaSevilla-Sanchez, MartaHerrera-Ramos, EstefaniaPulgar, SusanaBibiloni Esteva, Maria Del MarSistac-Sorigue, ClaraGomez, Santiago F2024-09-182024-09-182021-07-17Schroder H, Subirana I, Warnberg J, Medrano M, Gonzalez-Gross M, Gusi N, et al. Validity, reliability, and calibration of the physical activity unit 7 item screener (PAU-7S) at population scale. Int J Behav Nutr Phys Act. 2021 Jul 17;18(1):98.https://hdl.handle.net/20.500.13003/19904https://hdl.handle.net/20.500.12105/23155Background: Validation of self-reported tools, such as physical activity (PA) questionnaires, is crucial. The aim of this study was to determine test-retest reliability, internal consistency, and the concurrent, construct, and predictive validity of the short semi-quantitative Physical Activity Unit 7 item Screener (PAU-7S), using accelerometry as the reference measurement. The effect of linear calibration on PAU-7S validity was tested. Methods: A randomized sample of 321 healthy children aged 8-16 years (149 boys, 172 girls) from the nationwide representative PASOS study completed the PAU-7S before and after wearing an accelerometer for at least 7 consecutive days. Weight, height, and waist circumference were measured. Cronbach alpha was calculated for internal consistency. Test-retest reliability was determined by intra-class correlation (ICC). Concurrent validity was assessed by ICC and Spearman correlation coefficient between moderate to vigorous PA (MVPA) derived by the PAU-7S and by accelerometer. Concordance between both methods was analyzed by absolute agreement, weighted kappa, and Bland-Altman statistics. Multiple linear regression models were fitted for construct validity and predictive validity was determined by leave-one-out cross-validation. Results: The PAU-7S overestimated MVPA by 18%, compared to accelerometers (106.5 +/- 77.0 vs 95.2 +/- 33.2 min/day, respectively). A Cronbach alpha of 0.76 showed an acceptable internal consistency of the PAU-7S. Test-retest reliability was good (ICC 0.71 p < 0.001). Spearman correlation and ICC coefficients of MVPA derived by the PAU-7S and accelerometers increased from 0.31 to 0.62 and 0.20 to 0.62, respectively, after calibration of the PAU-7S. Between-methods concordance improved from a weighted kappa of 0.24 to 0.50 after calibration. A slight reduction in ICC, from 0.62 to 0.60, yielded good predictive validity. Multiple linear regression models showed an inverse association of MVPA with standardized body mass index (beta - 0.162; p < 0.077) and waist to height ratio (beta - 0.010; p < 0.014). All validity dimensions were somewhat stronger in boys compared to girls. Conclusion: The PAU-7S shows a good test-retest reliability and acceptable internal consistency. All dimensions of validity increased from poor/fair to moderate/good after calibration. The PAU-7S is a valid instrument for measuring MVPA in children and adolescents.enghttp://creativecommons.org/licenses/by/4.0/Children and adolescentsSelf-reported physical activityShort PAQValidationAccelerometryChildMaleAccelerometryCalibrationSedentary BehaviorFemaleHumansAdolescentReproducibility of Resultsresearch articleAttribution 4.0 International342740021819810.1186/s12966-021-01169-w1479-5868International Journal of Behavioral Nutrition and Physical Activityopen accessEjercicio FísicoHumanosReproducibilidad de los ResultadosConducta SedentariaCalibraciónAcelerometríaFemeninoEncuestas y CuestionariosNiñoAdolescenteMasculino2-s2.0-85110309274675608000001L2013156350