Background: Few questionnaires are tailored for siblings of children with disabilities. The Negative Adjustment Scale (NAS) was developed to measure siblings' adjustment, but has not yet been validated.Objective: To investigate the factor structure and convergent validity of the NAS.Method: We examined the validity of the NAS in terms of factor structure and convergent validity against a general mental health measure. The sample comprised 107 siblings (M age = 11.5 years, SD = 2.1, 53.8% boys) of children with disabilities.Results: We confirmed a one-factor structure for the NAS. Convergent validity was demonstrated through significant correlations (r=.29-.44) with sibling externalizing and internalizing mental health difficulties.Conclusion: The NAS holds promise as a measure tailored for the assessment of sibling's adjustment.
Keywords: Negative adjustment; confirmatory factor analysis; developmental disorders; mental health; physical disabilities; siblings.