Marie-Christine Opdenakker
Developments in early adolescents' self-regulation: The importance of teachers' supportive vs. undermining behavior
Frontiers in psychology
environmental research often relies urinary biomarkers require dilution correction accurately measure exposures specific gravity sg creatinine ucr commonly measured urinary dilution factors epidemiologic studies may assess one measures making difficult pool studies may otherwise able combined participants national health nutrition examination survey 20072008 cycle used perform kfold validation nonlinear model estimating sg ucr final estimated model applied participants school innercity asthma intervention study submitted urinary samples childrens health exposure analysis resource model performance evaluated using calibration metrics determine closely average estimated sg measured sg additional models interaction terms age sex body mass index raceethnicity relative time day sample collected log transformed 4methylnitrosamino13pyridyl1butanol nnal asthma status estimated assessed improvement association monobenzyl phthalate mbzp asthma symptom days controlling measured ucr measured sg estimated sg compared assess validity estimated sg model estimating sg ucr alone resulted beta estimate 110 95 ci 101 119 indicating agreement modelpredicted sg measured sg inclusion age sex model improved estimation 106 95 ci 098 115 full model accounting interaction terms ucr resulted best agreement 101 95 ci 093109 associations mbzp asthma symptoms days controlling estimated sg within range effect estimates controlling measured sg measured ucr rate ratios 128134 nonlinear modeling provides opportunities estimate sg studies measure ucr vice versa enabling data pooling despite differences urine dilution factors