Exploratory factor analysis of the Illness Intrusiveness Rating Scale for parents of children with atypical genital appearance due to differences of sex development (DSD)

Objective: Illness intrusiveness refers to the subjective cognitive appraisal of a chronic health condition interfering in daily, valued activities and may be highly relevant for parents of children with atypical genital appearance due to differences of sex development (DSD). However, a measure of illness intrusiveness has not been validated for this population. The current study aimed to evaluate the factor structure of the Illness Intrusiveness Scale for Parents (IIS-P) and examine convergent validity. Methods: Participants included 102 parents (M-age = 33.39 years, SD = 6.48; 58% mothers) of 65 children (<2 years old) diagnosed with DSD participating in a larger, longitudinal study. Parents completed the IIS-P as well as self-report measures of stigma, and anxious and depressive symptoms. An exploratory factor analysis (EFA) was conducted. Results: EFA results supported a 1-factor intrusiveness solution (alpha = .93), as well as a 2-factor solution measuring intrusiveness on daily living (alpha = .92) and community connectedness (alpha = .85). The 1-factor solution and both factors of the 2-factor solution demonstrated significant convergent validity with stigma as well as anxious and depressive symptoms. Conclusions: Support emerged for both 1- and 2-factor solutions of the IIS-P in parents of children with DSD. The decision to evaluate illness intrusiveness as a total score or to examine the subscales of daily living and community connectedness should be tailored to the unique aims of researchers and clinicians. Future research should conduct a confirmatory factor analysis with both 1- and 2-factor models with larger, more diverse samples of caregivers.