To evaluate the test-retest reliability, discriminative and concurrent validity, and responsiveness of the Childhood Atopic Dermatitis Impact Scale (CADIS), a quality-of-life scale with 5 domains.
Prospective, longitudinal study.
Two academic pediatric dermatology practices.
A total of 301 parents of children younger than 6 years with atopic dermatitis.
Main Outcome Measures
Participants completed the CADIS, sociodemographic items, and other clinical questions at enrollment and at a 4-week follow-up. In addition, 41 participants completed the CADIS again 48 hours after baseline. Disease severity was measured using the Severity Scoring of Atopic Dermatitis (SCORAD) index for all children.
Of 301 enrolled participants, 270 (90%) completed the enrollment materials and 228 (84%) of these completed the 4-week follow-up materials. Thirty-four (83%) of the 41 participants completed the 48-hour materials. Intraclass correlation coefficients of CADIS scores at enrollment and at 48 hours ranged from 0.89 to 0.95. Correlations between CADIS scores and the SCORAD index scores (range, 0.42-0.72) demonstrated that more severe atopic dermatitis is associated with worse quality of life. Scores from all 5 domains of the CADIS significantly differentiated patients at each severity level as measured by the SCORAD index (P<.001). Participants who rated their children as “improved” at the 4-week follow-up had significantly better CADIS scores than those who rated their children as having the “same” or “worse” skin disease (P<.05).
These data confirm the test-retest reliability, concurrent validity, and discriminative validity of the CADIS. In addition, responsiveness evaluation demonstrates that the CADIS accurately measures change in patients whose disease improves.