Validity, reliability, and calibration of the physical activity unit 7 item screener (PAU-7S) at population scale

Abstract

Background 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 (β − 0.162; p < 0.077) and waist to height ratio (β − 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. Trial registration Trial registration numberISRCTN34251612.

Determinants of Adherence to the Mediterranean Diet in Spanish Children and Adolescents: The PASOS Study

“…The validated PAU-7S, a seven-item self-reported questionnaire [19], was used to assess physical activity levels in children and adolescents. Six questions asked about physical activity frequency and duration in the previous week: (1) 'How many days did you go for a walk?…”

Development of the Children and Adolescents Physical Activity and Sedentary Questionnaire (CAPAS-Q): Psychometric Validity and Clinical Interpretation

“…Importantly, the choice of a 7-day timeframe was made per available evidence showing good reliability of weekly recalls [ 31 ]. Indeed, the time between a questionnaire’s first and second administrations is known to influence the test-retest reliability, and the highest coefficients are usually obtained for a shorter timeframe [ 32 ].…”

“…PA and SB were measured by an ActiGraph GT3X+ accelerometer (ActiGraph, Pensacola, FL, USA), previously used for validity and reliability studies in similar populations [ 32 ]. The Troiano et al method has been used to identify the time that accelerometers were not worn: periods of 60 min (or more) of zero values were excluded [ 35 ].…”

Physical Activity Levels and Sleep in Schoolchildren (6–17) with and without School Sport

“…The record of physical activity (time and type), sleep time and its efficiency [46][47][48] were collected in the most valid and reliable way [49]. In addition, like other authors, a diary was filled out that collected data such as sleep time, mode of transportation to school or other places and the type of physical activity they perform [50]. Waking hours were classified as sedentary time, light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous physical activity (MVPA) [51] recommended as cut-points from previous research [52].…”