The validity, reliability and normative scores of the parent, teacher and self report versions of the Strengths and Difficulties Questionnaire in China

Background: The Strengths and Difficulties Questionnaire (SDQ) has become one of the most widely used measurement tools in child and adolescent mental health work across the globe. The SDQ was originally developed and validated within the UK and whilst its reliability and validity have been replicated in several countries important cross cultural issues have been raised. We describe normative data, reliability and validity of the Chinese translation of the SDQ (parent, teacher and self report versions) in a large group of children from Shanghai. Methods: The SDQ was administered to the parents and teachers of students from 12 of Shanghai's 19 districts, aged between 3 and 17 years old, and to those young people aged between 11 and 17 years. Retest data was collected from parents and teachers for 45 students six weeks later. Data was analysed to describe normative scores, bandings and cut-offs for normal, borderline and abnormal scores. Reliability was assessed from analyses of internal consistency, inter-rater agreement, and temporal stability. Structural validity, convergent and discriminant validity were assessed. Results: Full parent and teacher data was available for 1965 subjects and self report data for 690 subjects. Normative data for this Chinese urban population with bandings and cut-offs for borderline and abnormal scores are described. Principle components analysis indicates partial agreement with the original five factored subscale structure however this appears to hold more strongly for the Prosocial Behaviour, Hyperactivity - Inattention and Emotional Symptoms subscales than for Conduct Problems and Peer Problems. Internal consistency as measured by Cronbach's a coefficient were generally low ranging between 0.30 and 0.83 with only parent and teacher Hyperactivity - Inattention and teacher Prosocial Behaviour subscales having a <0.7. Inter-rater correlations were similar to those reported previously (range 0.23 - 0.49) whilst test retest reliability was generally lower than would be expected (range 0.40 - 0.79). Convergent and discriminant validity are supported. Conclusion: We report mixed findings with respect the psychometric properties of the Chinese translation of the SDQ. Reliability is a particular concern particularly for Peer Problems and self ratings by adolescents. There is good support for convergent validity but only partial support for structural validity. It may be possible to resolve some of these issues by carefully examining the wording and meaning of some of the current questions