Normative data and psychometric properties of the Thai version of the Strengths and Difficulties Questionnaire (SDQ)

Objective: To study normative data and psychometric properties of the Thai Strengths and Difficulties Questionnaire (SDQ; parent-, teacher-, and self-rated forms), which addresses positive and negative aspects of childrenus and adolescentsu behaviour and generates clinically relevant scale scores. Materials and Methods: Using multistage random cluster sampling method, data were collected in 13 provinces from parents, teachers, and as self-reports of 9,491 children aged between 5 and 16 years. Evaluation methods included scale reliability analyses (Cronbachus alpha), correlations with age and among scales, testing for gender effects, and comparing urban and rural regions. A factor analysis examines the specific scale structure of the Thai parent-rated SDQ. Bandings are recommended to identify normal, borderline, and abnormal score ranges. Results Problem scores were higher than those observed in Western countries, stressing the necessity to establish national norms. Thai SDQ norms identify probable behaviour problems if the total difficulties score is 19-40 in the parent-rated form, 17-40 in the teacher form, and/or 19-40 in the self-report. Internal reliabilities were satisfactory for all but one subscale. Age and gender effects on SDQ scores as well as correlations between subscales were well in line with the English original and its many other translated versions. Conclusion The Thai SDQ was shown to possess sufficiently favourable psychometric properties. Thus, this instrument promises to be a useful assessment and screening tool, as in other parts of the world. Ongoing validation studies and cross-cultural comparisons will provide further culture-specific findings.