A preliminary validation of the pediatric adaptation of the Insomnia Severity Index.

INTRODUCTION:The prevalence of insomnia in children aged 5 to 12 years old is 20% to 31%. Currently, there is no well-validated questionnaire assessing all the components of insomnia in school-aged children. The present study aims to introduce an adaptation of the Insomnia Severity Index for this purpose. METHOD:Fifty-nine children aged 8- to 12-years-old with at least one anxiety disorder were recruited from youth mental health care settings. Their parents completed the pediatric adaptation of the Insomnia Severity Index which includes two scales used to report insomnia symptoms in children and their impact on the child (ISI-Child) and parents (ISI-Parent), My Child's Sleep Habits questionnaire, and the Child Behavior Checklist. RESULTS:Both the ISI-Child and the ISI-Parent scales presented adequate factorial structure (RMSEA ≤ 0.05) and internal consistency (ISI-Child: α=0.87; ISI-Parent: α=0.88). Furthermore, the results of the two scales were strongly correlated (r=0.91, P<0.001). The convergent validity was assessed using the Waking During the Night scale of the My Child's Sleep Habits questionnaire and was adequate for the ISI-Child (r=0.52, P<0.001) and the ISI-Parent (r=0.53, P<0.001). Finally, the Rule-Breaking Behavior (r ≤ 0.26, P ≥ 0.05) and Aggressive Behavior (r ≤ 0.19, P ≥ 0.19) scales of the Child Behavior Checklist showed small correlations with both subscales, indicating good divergent validity. CONCLUSION:The pediatric adaptation of the Insomnia Severity Index is a potentially reliable and valid measure for screening and assessing insomnia in children.