Utility of the Illness Intrusiveness Scale in parents of children diagnosed with juvenile rheumatic diseases.

OBJECTIVE To examine the factor structure and convergent validity of the Illness Intrusiveness Scale--Parent Version in mother and fathers of children and adolescents ages 7 to 18 (M = 13.56 years, SD = 2.67) diagnosed with a juvenile rheumatic disease. DESIGN Parents of 122 children and adolescents (82 girls, 40 boys) completed the Illness Intrusiveness Scale-Parent Version, and both parents and children and adolescents completed measures of functional disability, general distress, and illness uncertainty. An exploratory factor analysis was conducted on the Illness Intrusiveness Scale--Parent Version to identify the factor structure. The factors were then compared with parent- and child-report measures of functional disability, general distress, and uncertainty. Finally, analyses were conducted to determine whether the magnitude of the correlations was significantly different between factors for parents and children and adolescents. RESULTS The Illness Intrusiveness Scale--Parent Version was found to have a two-factor structure. The Relationships/Personal Development factor contained items related to self-fulfillment and interactions with others, and the Instrumental factor contained items related to health and work. These factors were found to have good internal consistency and were significantly correlated with measures of parent-reported functional disability and parent- and youth-reported distress and uncertainty. The magnitude of these correlations was also found to differ depending on informant and outcome measure. CONCLUSION The Illness Intrusiveness Scale--Parent Version appears to be a valid measure for use in parents of children with juvenile rheumatic disease.