The Family Strain Index (FSI). Reliability, validity, and factor structure of a brief questionnaire for families of children with ADHD

Abstract

Background: Attention-deficit/hyperactivity disorder (ADHD) in children affects every member of the family. Practical tools are needed to assess the effects of ADHD on families to better understand and address the level of stress, strain and burden that families experience.

Objective: To provide the preliminary reliability, validity and factor structure of the Family Strain Index (FSI), a 6-item parent-report questionnaire.

Methods: The FSI was completed by 1,477 parents of children with ADHD (aged 6-18 years) at the baseline visit of the ADORE study in 10 European countries (data missing for one patient).

Results: The FSI taps into an overall experience of worry and interruptions of activities in families of children with ADHD, as a single factor was identified with excellent internal consistency (alpha=0.87). Despite its brevity, almost no ceiling (worst score) or floor (best score) effects were observed for families of these highly symptomatic children. This score distribution and the 5-point response options suggest that the FSI will be responsive to changes in the experience of family strain associated with children's ADHD treatment.

Conclusion: The ease of completion and coherence of the underlying construct indicates that the FSI may be a practical clinical tool for monitoring changes in family strain associated with children's ADHD treatment.