Psychometric properties of online administered parental strengths and difficulties questionnaire (SDQ), and normative data based on combined online and paper-and-pencil administration

OBJECTIVE To examine the psychometric properties of the online administered parental version of the Strength and Difficulties Questionnaire (SDQ), and to provide parental norms from a nationwide Swedish sample. METHODS A total of 1443 parents from of a national probability sample of 2800 children aged 10-13 years completed the SDQ online or as usual (i.e., using paper-and-pencil). RESULTS The SDQ subscales obtained from the online administration showed high internal consistency (polychoric ordinal alpha), and confirmatory factor analysis of the SDQ five factor model resulted in excellent fit. The Total Difficulties score of the SDQ and its other subscales were significantly related to the Disruptive Behavior Disorders (DBD) rating scale. Norms for the parent version of SDQ obtained from the Internet were identical to those collected using paper-and-pencil. They were thus combined and are presented sorted by child gender and age. CONCLUSIONS The SDQ seems to be a reliable and valid instrument given its high internal consistency, clear factor structure and high correlation with other instruments capturing the intended constructs. Findings in the present study support its use for online data collection, as well as using norms obtained through paper-and-pencil-administration even when SDQ has been administrated online.