Activity During Sleep Measured by a Sheet-Shaped Body Vibrometer and the Severity of Atopic Dermatitis in Adults: A Comparison With Wrist Actigraphy

Abstract

Study Objectives: To use a sheet-shaped body vibrometer (SBV) for measuring sleep in adult patients with atopic dermatitis (AD) of various severities and to compare the results with those measured by wrist actigraphy (WA). Methods: Simultaneous measurements of activity during sleep by WA and the SBV were performed in 20 outpatients with AD for 5 to 10 days. The mean activity count per minute (ACT) and sleep efficiency (SE) were obtained using each device. The severity of AD was evaluated by the severity scoring of AD (SCORAD), serum thymus and activation-regulated chemokine (TARC) level, serum total immunoglobulin E level, and peripheral eosinophil count. Results: The ACT measured by WA was correlated with SCORAD (Spearman correlation coefficient [rs] = .64, P = .002) and TARC (rs = .60, P = .005). The ACT obtained by the SBV was significantly correlated with TARC (rs = .58, P = .008) and ACT obtained by WA (rs = .63, P = .003). SE obtained by WA resulted in lower values compared with SE obtained by the SBV (69.7 ± 9.4% versus 82.9 ± 9.3%, P < .001), although SE obtained by WA was highly correlated with SE obtained by the SBV (rs = .82, P < .001). Bland-Altman plots revealed that SE measured by WA always had lower values in all the patients. Conclusions: Activity during sleep, presumably composed of scratching and other motions, is more vigorous in patients with severe adult AD. This was successfully demonstrated by the SBV and WA assessment. However, we consider that ACT measured by WA is more suited for the scratch evaluation and SE measured by the SBV is preferable for the sleep evaluation.