Actigraphy is poor measure of eczema activity

(HealthDay)—The use of actigraphy to record movement as an objective surrogate for eczema activity is of limited use, according to a study published in the November issue of the British Journal of Dermatology.

Catriona I. Wootton, M.B., Ch.B., from Queen's Medical Centre in Nottingham, U.K., and colleagues collected accelerometer data from 336 participants in the Softened Water Eczema Trial to evaluate its validity as an objective measure of itch assessment in eczema. Data from actigraphy monitors were compared to three standardized scales: Six Area, Six Sign Atopic Dermatitis (SASSAD) severity score; Patient Oriented Eczema Measure (POEM); and Dermatitis Family Impact (DFI).

The researchers found that there was poor convergence of the validity of the accelerometer data with the other measures of eczema severity, with a correlation between the actigraphy and SASSAD of 0.15 (P = 0.02) and actigraphy and POEM 0.10 (P = 0.13). The correlation with the DFI was low on assessment for divergent validity against quality-of-life measures. Low, negative correlations were found when comparing the change scores from baseline to week 12 for SASSAD, POEM, and DFI with the change in accelerometer scores. The meters were generally well tolerated.

"Actigraphy did not correlate well with disease severity or quality of life when used as an objective outcome measure in a multicenter clinical trial, and was not responsive to change over time," the authors write. "Further work is needed to establish why this might be, and to establish improved methods of distinguishing between eczema-related and eczema-nonrelated movements."