title: Psychometric Properties and Normative Data for the Preschool Strengths and Difficulties Questionnaire in Two-Year-Old Children.
abstract: The Strengths and Difficulties Questionnaire (SDQ) is a popular standardised instrument typically used for screening psychopathology in children and adolescents. However, peer reviewed studies evaluating the psychometric properties of the parent-rated preschool SDQ are lacking. The current study involved mothers of 5481 2 year olds (52 % male) from the Growing Up in New Zealand cohort, and investigated the psychometric properties of the preschool SDQ within this cohort. Confirmatory factor analysis was used to evaluate the SDQ's factor structure and test for measurement invariance of the factor model. Cronbach's alpha was used to measure the internal consistency of the subscales and total difficulties scale. We found support for a modified five-factor model, in which the prosocial factor was extended into a positive construal factor by allowing cross-loadings of reverse-scored items. Full measurement invariance was found across gender and socioeconomic status, and partial invariance was found across mother's ethnicity. Cronbach's alpha was satisfactory for all subscales (α range = 0.71-0.84), except peer problems (α = 0.54). Normative scores and bandings for normal, borderline and abnormal ranges are described for each subscale. Analyses revealed group differences in scores for child's gender, mother's ethnicity and socioeconomic status. Overall, satisfactory psychometric properties were found for the preschool SDQ in 2 year olds, indicating that that the questionnaire can be used in very young children.
authors.affiliation: School of Psychology, Faculty of Science, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.|Centre for Longitudinal Research - He Ara ki Mua, The University of Auckland, Auckland, New Zealand.
authors.forename: Stephanie
authors.initials: S
authors.lastname: D'Souza
authors.affiliation: School of Psychology, Faculty of Science, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand. k.waldie@auckland.ac.nz.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Waldie
authors.affiliation: School of Psychology, Faculty of Science, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Peterson
authors.affiliation: Centre for Longitudinal Research - He Ara ki Mua, The University of Auckland, Auckland, New Zealand.
authors.forename: Lisa
authors.initials: L
authors.lastname: Underwood
authors.affiliation: Centre for Longitudinal Research - He Ara ki Mua, The University of Auckland, Auckland, New Zealand.|School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Susan M B
authors.initials: SM
authors.lastname: Morton
mesh_terms: D000342:Affective Symptoms / Q000175:diagnosis*; D002652:Child Behavior / Q000523:psychology*; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D000066553:Problem Behavior / Q000523:psychology*; D011594:Psychometrics / Q000295:instrumentation*; D012016:Reference Values; D012919:Social Behavior; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Child behaviour; Cohort; Factor analysis; Longitudinal; Measurement invariance; Preschool; Psychometrics; SDQ; Validity