The Impact on Family Scale: Psychometric analysis of long and short forms in parents of children with epilepsy

• The Impact on Family Scale (IOFS) is appropriate for parents of children with epilepsy.
• IOFS-11 and IOFS-15 are reliable and valid tools to assess the impact of epilepsy on family.
• Factor analyses indicate superior characteristics of the short form with 11 items.

Epilepsy in a child or adolescent can have severe psychosocial impact on the whole family and burdens them, especially the parents. As the familial background is essential for the child's coping and the progression of the epilepsy, parental burden should be considered within a comprehensive treatment approach. This study validated the applicability of the Impact on Family Scale (IOFS), a well-established instrument that assesses the strains of families with chronically ill or disabled children, in parents of children with epilepsy. In a sample of 219 parents, the psychometric properties of the original IOFS version (33 items) and two short forms (15 and 11 items, respectively) were examined. Both short forms revealed good reliability (Cronbach's alpha, test–retest reliability), and construct validity was verified by correlations with epilepsy- and burden-related variables. However, exploratory and confirmatory factor analyses indicated superior characteristics of the short form with 11 items (IOFS-11). In conclusion, the IOFS-11 as well as the IOFS-15 proved to be practicable, reliable, and valid tools to assess the impact of childhood epilepsy on family life in research and clinical practice.