How should minimally important change scores for the Patient‐Oriented Eczema Measure be interpreted? A validation using varied methods3. (17th April 2018)

• Record Type: Journal Article
• Authors: Howells, L.; Ratib, S.; Chalmers, J.R.; Bradshaw, L.; Thomas, K.S.
• Is Part Of: British journal of dermatology. Volume 178:Number 5(2018)
• Page Start: 1135
• Page End: 1142
• Publication Date: 2018-04-17
• Subjects: Dermatology -- Periodicals; Skin -- Diseases -- Periodicals; 616.5
• DOI: 10.1111/bjd.16367
• Languages: English
• ISSNs: 0007-0963

Abstract

Summary: Background: The Patient‐Oriented Eczema Measure (POEM), scored 0–28, is the core outcome instrument recommended for measuring patient‐reported atopic eczema symptoms in clinical trials. To date, two published studies have broadly concurred that the minimally important change (MIC) of the POEM is three points. Further assessment of the MIC of POEM in different populations, and using a variety of methods, will improve interpretability of the POEM in research and clinical practice. Objectives: To calculate the smallest detectable change in the POEM and estimate the MIC of the POEM using a variety of methods in a trial dataset of children with moderate‐to‐severe atopic eczema. Methods: This study used distribution‐based and anchor‐based methods to calculate the MIC of the POEM in children with moderate‐to‐severe eczema. Results: Data were collected from 300 children. The smallest detectable change was 2·13. The MIC estimates were 1·07 (using 0·2 SD of baseline POEM scores) and 2·68 (using 0·5 SD of baseline POEM scores) based on distribution‐based methods; were 3·09–6·13 based on patient‐/parent‐reported anchor‐based methods; and were 3·23–5·38 based on investigator‐reported anchor‐based methods. Conclusions: We recommend the following thresholds be used to interpret changes in POEM scores: ≤ 2, unlikely to be a change beyond measurement error; 2·1–2·9, a small change detected that is likely to be beyond measurement error but may not be clinically important; 3–3·9, probably a clinically important change; ≥ 4, very likely to be a clinically important change. Abstract : What's already known about this topic? The Patient‐Oriented Eczema Measure (POEM) is recommended as the core outcome instrument for measuring patient‐reported symptoms in eczema clinical trials. Two previous studies have examined the minimally important change (MIC) of the POEM; one in children with mild eczema and another in adults with very severe eczema. These previous studies both concluded that the MIC in POEM is around three points. What does this study add? This study explored the impact of different methodologies for calculating the MIC of the POEM in children with moderate‐to‐severe eczema. A change in POEM of less than two points is likely to be below the smallest detectable change (i.e. below measurement error) for the scale. The MIC varied considerably depending on the method used, but a change in POEM score below three points is unlikely to be a clinically important change. What are the clinical implications of this work? This study aids sample size calculations for clinical trials and helps researchers, clinicians and patients to interpret changes in POEM scores in clinical trials and routine monitoring of eczema in clinical practice. Plain language summary available online Respond to this article