Measuring long-term disease control in patients with atopic dermatitis: A validation study of well-controlled weeks

Langan, Sin�ad M.; Stuart, Beth; Bradshaw, Lucy; Schmitt, Jochen; Williams, Hywel C.; Thomas, Kim S.

Abstract

Background:Because atopic dermatitis (AD) is a relapsing, remitting disease, assessing long‐term control is important. Well controlled weeks (WCWs) have been used to assess asthma long‐term control, but never validated for AD.
Objectives: To assess feasibility, validity and interpretability of WCWs in AD patients.
Methods: Three studies of patients with moderate‐to‐severe AD including 4‐6 months of daily/weekly symptom and treatment use data were evaluated (Study A: n=336; Study B: n=60; Study C: n=224). WCWs were defined by worsening symptoms and increased medication use. Feasibility, construct validity and interpretability of WCWs were determined by assessing missing data, association with validated AD outcomes, and floor/ceiling effects. Analysis used linear and logistic regression.
Results: WCWs were feasible to collect ‐ 95.2% (study A) and 94.7% (study B) contributed data for at least half of the weekly data‐points, and 93.2% and 88.7% contributed to all data‐points up to 4 months. WCWs were significantly associated with validated AD severity instruments including patient-reported (POEM) and objective signs (EASI, TIS and SASSAD). The odds of experiencing a WCW if AD severity was clear/mild was 5.8 (95% confidence interval (CI) 3.5 to 9.7), 1.9 (95%CI 0.8 to 4.4) and 8.1 (95%CI 4.5 to 14.6) in Studies A, B and C, respectively. WCWs were associated with ceiling effects‐ 31.6% (study A) and 37.5% (study B) of participants had no WCWs for >90% of the time.
Conclusions: WCWs are valid and feasible for measuring long‐term control in AD trials. However, ceiling effects and burden of data collection may limit use.

Citation

Langan, S. M., Stuart, B., Bradshaw, L., Schmitt, J., Williams, H. C., & Thomas, K. S. (2017). Measuring long-term disease control in patients with atopic dermatitis: A validation study of well-controlled weeks. Journal of Allergy and Clinical Immunology, 140(6), 1580-1586. https://doi.org/10.1016/j.jaci.2017.02.043

• Journal Article Type: Article
• Acceptance Date: Feb 9, 2017
• Online Publication Date: Apr 26, 2017
• Publication Date: 2017-12
• Deposit Date: Feb 13, 2017
• Publicly Available Date: Apr 26, 2017
• Journal: Journal of Allergy and Clinical Immunology
• Print ISSN: 0091-6749
• Electronic ISSN: 1097-6825
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 140
• Issue: 6
• Pages: 1580-1586
• DOI: https://doi.org/10.1016/j.jaci.2017.02.043
• Keywords: AD, long‐term control, outcome measures
• Public URL: https://nottingham-repository.worktribe.com/output/898045
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0091674917306772
• Contract Date: Feb 13, 2017