OBJECTIVES:

Many Clinical Outcome Assessments (COA) exist for measuring symptoms and impacts of atopic dermatitis (AD). As such, interpretability can be challenging. A linking approach investigating severity strata may be used in interpretability of multiple outcomes

METHODS:

A 2019 survey of AD patients was conducted in 2019. Patients were asked to report their AD severity at time of survey utilizing a patient global item: mild, moderate or severe. Physicians provided their assessment of AD for patients as Clear, Almost Clear, Mild, Moderate, or Severe. Physicians also rated body surface area (BSA). Patients completed the Dermatology Life Quality Index (DLQI) and Patient Oriented Eczema Measure (POEM) questionnaires. The BSA, DLQI and POEM were linked to measures of AD severity by using an equipercentile approach to obtain severity strata. Agreement of linked severity and original severity was assessed by kappa coefficient.

RESULTS:

Five hundred fifty-seven patients (48.3% male) completed severity, BSA, DLQI and POEM questionnaires. The average age was 38.9 years (SD: 16.3). Patients reported 49% mild, 40% moderate and 9% severe. Physician assessed 6.1% clear, 15.8% almost clear, 23.5% mild, 50.8% moderate, and 3.8% severe.

When linked to patient-reported severity, we estimated severity strata for: BSA (mild 0-7.0, moderate 7.1-28.0, severe 28.1-99, κ=0.27), DLQI (mild 0-5, moderate 6-15, severe 16-30, κ=0.39), and POEM (mild 0-8, moderate 9-19, severe 20-28; κ=0.47) from a patient’s perspective. When linked to the physician-assessed severity, severity strata from the physicians perspective was also captured: BSA (clear 0-0.49, almost clear 0.5-1.8, mild 1.81-6.39, moderate 6.40-44.0, severe >44.0; κ=0.19), DLQI (clear 0, almost clear 1, mild 2-5, moderate 6-18, severe 19-30; κ=0.26), and POEM (clear 0, almost clear 1-3, mild 4-7, moderate 8-24, severe 25-28; κ=0.29).

CONCLUSIONS:

Identifying severity strata and linking can assist in interpretability.