Jiahui Chen, Eugene Scott Huebner, Lili Tian
Longitudinal associations among academic achievement and depressive symptoms and suicidal ideation in elementary schoolchildren: disentangling between- and within-person associations
European child & adolescent psychiatry
use uniaxial summary measures accelerometry ie counts per minute minutes spent moderatetovigorous intensity substantially restricts information physical activity pa probably result reliance analytic approaches cannot handle collinear variables present study aimed determine multivariate triaxial pa intensity signature related metabolic health children investigating associations whole spectra pa intensities axes using multivariate pattern analysis included 841 children age 102 03 yr body mass index 180 30 50 boys active smarter kids study conducted norway 2014 2015 providing valid data accelerometry actigraph gt3x several indices metabolic health aerobic fitness abdominal fatness insulin sensitivity lipid metabolism blood pressure used create composite metabolic health score created intensity spectra 0 100 10000 counts per minute separate axes used multivariate pattern analysis analyze data explained variance metabolic health 32 counts per minute vertical axis 170 vertical axis intensity spectrum 295 full model including axes thus including full triaxial intensity spectra improved model metabolic health tenfold compared using overall pa counts per minute vertical axis intensity signature associated metabolic health differed across axes findings show three different axes carry distinct information childrens pa relation pa health demonstrate great potential triaxial accelerometry multivariate analytic approach advance field pa epidemiology