Evaluating patient-perceived control of atopic dermatitis: design, validation, and scoring of the Atopic Dermatitis Control Tool (ADCT).

The Atopic Dermatitis Control Tool (ADCT) was designed to evaluate patient-perceived AD control and facilitate patient-physician discussion on long-term disease control. The study was performed in adult patients with AD. Development of the ADCT followed US Food and Drug Administration (FDA) guidelines on patient-reported outcome measures (PROMs). Qualitative research, including targeted literature review, interviews with clinical experts, and combined concept elicitation/cognitive debriefing with patients with AD, was conducted to provide a list of comprehensive concepts capturing AD control per physician and patient perspectives. Quantitative methods assessed psychometric properties of the instrument and defined the threshold for AD control. The resulting pilot six-item ADCT, reflecting key concepts related to AD control, had 7-day recall and assessed symptoms and impacts on patients' everyday lives by severity and/or frequency. The ADCT showed good content validity (well understood by adult patients with AD), and quick completion time (<2 min). Psychometric analysis indicated no floor/ceiling effects for response distributions, particularly strong ( ≥ 0.80) inter-item correlations for the six ADCT items, robust construct validity ( > 0.50), and item-level discriminating ability ( < .03); this supported the derivation of a total score based on responses to all items. ADCT total score showed evidence of strong internal consistency reliability (Cronbach's alpha >0.80). A score ≥7 points was identified as an optimum threshold to identify patients whose AD is "not in control." No single validated instrument has been available to holistically evaluate patient-perceived AD control. The newly developed ADCT displays good-to-excellent content validity, construct validity, internal consistency, reliability, and discriminating ability.

PMID: 31778083