Looij-Jansen, P.M. van de

health study questionnaire factor problem school adolescent weight self-report model behaviour youth pupil level group self-reported difference children child gender parent sample rotterdam scale score question effect research invariance validity education police measure result dutch health indicators netherland behavior height response difficulties questionnaire factorial invariance intervention method peer problems strength number analysis condition background factorial indicator table report weight status internalizing problems status measurement survey dif ficulties questionnaire correlation journal prosocial chapter internalizing determinant difficulty self-report sdq activity population data collection psychiatry confidentiality well-being obesity reverse-worded items self-reported height percent privacy alcohol