The Patient-Oriented Eczema Measure: estimating the minimal important change in an outpatient clinic cohort

Patient-Oriented Eczema Measure (POEM) measures patient-reported symptoms in atopic dermatitis (AD). It is the recommended core outcome instrument to capture the symptoms domain in AD clinical trials. Understanding the minimal important change (MIC) in the POEM score is therefore important in both trial and clinical care settings. Previous studies have mainly evaluated MIC estimates among children in trial settings. The MIC estimate for POEM in a clinical setting is often lacking.

We aim to estimate the MIC of the POEM using both distribution-based and anchor-based methods in a clinical cohort of adult eczema patients.

Both distribution-based and anchor-based methods were used to calculate the MIC of the POEM in a clinical cohort of Asian adult patients attending the eczema clinic at a tertiary dermatology centre in Singapore. Scoring AD (SCORAD) was used as the disease severity anchor for the anchor-based methods. The smallest detectable change (SDC) for POEM was also calculated as the threshold for any measurement error.

There were a total of 85 adult AD patients in the cohort that contributed a total of 114 paired measurements of both POEM and SCORAD. The SDC in our study was 1.68. The MIC estimates were 3.64 and 1.46 based on 0.5 standard deviation (SD) and 0.2 SD distribution-based methods. Anchor-based methods such as the receiver operating curve and predictive modelling methods yielded MIC values of 0.50 and 1.05, respectively.

Minimal important change for POEM varied according to the methods and approaches used. Only a change of two points or more in POEM could be considered beyond any measurement errors and clinically important. This finding is consistent even in a clinical setting of Asian adults with eczema.