title: The Strengths and Difficulties Questionnaire: psychometric properties of the parent and teacher version in children aged 4-7.
abstract: BACKGROUND
  The Strengths and Difficulties Questionnaire is one of the most employed screening instruments. Although there is a large research body investigating its psychometric properties, reliability and validity are not yet fully tested using modern techniques. Therefore, we investigate reliability, construct validity, measurement invariance, and predictive validity of the parent and teacher version in children aged 4-7. Besides, we intend to replicate previous studies by investigating test-retest reliability and criterion validity.
  
  
  METHODS
  In a Dutch community sample 2,238 teachers and 1,513 parents filled out questionnaires regarding problem behaviors and parenting, while 1,831 children reported on sociometric measures at T1. These children were followed-up during three consecutive years. Reliability was examined using Cronbach's alpha and McDonald's omega, construct validity was examined by Confirmatory Factor Analysis, and predictive validity was examined by calculating developmental profiles and linking these to measures of inadequate parenting, parenting stress and social preference. Further, mean scores and percentiles were examined in order to establish norms.
  
  
  RESULTS
  Omega was consistently higher than alpha regarding reliability. The original five-factor structure was replicated, and measurement invariance was established on a configural level. Further, higher SDQ scores were associated with future indices of higher inadequate parenting, higher parenting stress and lower social preference. Finally, previous results on test-retest reliability and criterion validity were replicated.
  
  
  CONCLUSIONS
  This study is the first to show SDQ scores are predictively valid, attesting to the feasibility of the SDQ as a screening instrument. Future research into predictive validity of the SDQ is warranted.
authors: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, Nijmegen, 6500 HE The Netherlands.
authors: Lisanne L
authors: LL
authors: Stone
authors: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, Nijmegen, 6500 HE The Netherlands.
authors: Jan M A M
authors: JM
authors: Janssens
authors: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, Nijmegen, 6500 HE The Netherlands.
authors: Ad A
authors: AA
authors: Vermulst
authors: Radboud University Nijmegen, Nijmegen, The Netherlands.
authors: Marloes
authors: M
authors: Van Der Maten
authors: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, Nijmegen, 6500 HE The Netherlands.
authors: Rutger C M E
authors: RC
authors: Engels
authors: Behavioural Science Institute, Radboud University Nijmegen, P.O. Box 9104, Nijmegen, 6500 HE The Netherlands.
authors: Roy
authors: R
authors: Otten
keywords: Coefficient omega; Construct validity; Measurement invariance; Predictive validity; SDQ