Measurement of morphological and physiological skin properties in aged care residents: a test-retest reliability pilot study

This test-retest pilot study investigated the intra-rater reliability and reproducibility of non-invasive technologies to objectively quantify morphological (colour, thickness and elasticity) and physiological (transepidermal water loss (TEWL), hydration, sebum and pH) skin properties in an aged care population. Three consecutive measurements were taken from five anatomical skin sites, with the mean of each measurement calculated. The intra-class correlation coefficient (ICC) and the standard error of measurement (SEM) were used to examine the intra-rater reliability and reproducibility of measurements. Non-invasive technologies in this study showed almost perfect reliability for ultrasound measurements of the subepidermal low echogenicity band (SLEB) (rho=0.95-0.99) and skin thickness (rho=0.95-0.99) across all sites. The ICC was substantial to almost perfect for pH (rho=0.76-0.88) and viscoelasticity (rho=0.67-0.91) across all sites. Hydration (rho=0.53-0.85) and skin retraction (rho=0.57-0.99) measurements ranged from moderate to almost perfect across all sites. TEWL and elasticity were substantial to almost perfect across four sites. Casual sebumlevels and most colour parameters showed poor ICC. The use of non-invasive technologies in this study provided an objective and reliable means for quantifying ageing skin and may offer future studies a valuable option for assessing skin tear risk.