Objectives: The purpose of the study was to determine whether characterizing skin temperature regulation as a functional property of the skin as it relates to tissue tolerance improves the clinician's understanding of pressure ulcer risk prediction.
Design: A 2-group time-series design was used to observe skin temperature regularity (entropy) and self-similarity (spectral exponent).
Methods: Twenty nursing facility residents wore skin temperature monitors continuously for 5 days. One bathing episode was observed because bathing is a commonly occurring care procedure.
Primary outcome measure: Difference in skin temperature multiscale entropy and spectral exponent by risk category and pressure ulcer outcome.
Results: Multiscale entropy (MSE) for skin temperature was lowest in those who developed pressure ulcers, F1,18 = 35.14, P < .001. Skin temperature mean MSE, F1,17 = 5.55, P = .031 and the skin temperature spectral exponent, F1,17 = 6.19, P = .023 differentiated the risk groups. The change in skin temperature entropy during bathing was significant, t(16) = 2.55, P = .021.
Conclusions: Skin temperature MSE and the spectral exponent were significantly different between low-risk and higher risk residents and residents who did and did not develop pressure ulcers. The study supports measurement of skin temperature regulation as a component of tissue tolerance to pressure.