Initial validation of the product of the signs global assessment and body surface area in atopic dermatitis.

BACKGROUND

Current valid instruments that measure the signs of atopic dermatitis in clinical trials may not be suitable for clinical practice because of their complexity. The product of a clinician-derived 5-point signs global assessment and body surface area (SGA × BSA) may represent a simple approach to quickly assess the severity of signs in patients with atopic dermatitis in clinical practice.

OBJECTIVES

Evaluate the basic measurement properties of the SGA × BSA.

METHODS

Retrospective chart review of patients with atopic dermatitis treated in an outpatient dermatology clinic at Oregon Health & Science University from 2015 to 2018 who had a recorded BSA and SGA.

RESULTS

We identified 138 patients completing 325 clinic visits. SGA × BSA demonstrated strong and statistically significant (P < .001) correlations with the Eczema Area and Severity Index (r = 0.91, n = 19), average daily pruritus (r = 0.71, n = 177), patient global assessment (r = 0.74, n = 170), and a derived global scale composed of the average of 4 signs rated between 0 and 3 (r = 0.77, n = 282). Acceptability, responsiveness, and floor or ceiling effects of the measure were deemed adequate. Severity banding was maximized at 1, 21, and 87 (κ = 0.4902).

LIMITATIONS

The patient cohort was gathered exclusively from a tertiary care clinic setting in the Pacific Northwest and lacked ethnic diversity.

CONCLUSIONS

The results from this study suggest that SGA × BSA is a valid and feasible instrument for atopic dermatitis signs in clinical practice.