Reliability and agreement of instrumental skin barrier measurements in clinical pressure ulcer prevention research

Abstract

In skin and wound research the instrumental measurement of skin function is established. Despite the widespread use, empirical evidence about measurement errors is widely lacking. The aim of this study was to measure reliability and agreement of skin temperature, transepidermal water loss, epidermal hydration, and erythema at the heel and sacral skin. Four experienced researchers performed skin measurements in 15 subjects. Lowest reliability was observed for transepidermal water loss at the sacral skin (ICC (1) 0.46 (95% CI 0.00‐0.78)) and highest for skin temperature at the heel skin (ICC (1) 0.99 (95% CI 0.99‐1.00)). Lowest Standard Errors of Measurement were calculated for skin temperature measurements at the heels (0.11°C) and highest for erythema measurements at the sacral skin (26.7 arbitrary units). There was a clear association between variability of estimates and reliability coefficients. Single measurements of skin temperature, stratum corneum, and epidermal hydration at the sacral and heel skin areas can be used in clinical research and practice. Means of at least two measurements should be used for estimating transepidermal water loss and erythema. Evidence is needed to inform researchers about relative and absolute measurement errors of commonly applied instruments and measurements in skin and wound research.

The effect of a basic skin care product on the structural strength of the dermo‐epidermal junction: An exploratory, randomised, controlled split‐body trial

“…Values are expressed in arbitrary units (AU) and range from 0 to 120, with higher values indicating higher SCH. Absolute measurement errors of SCH measurements in terms of upper and lower limits of agreement are expected to be +4 AU and − 4 AU 42,43 and reliability coefficients exceed 0.9 42,43 . Therefore, comparisons of means within and between groups are justified 44 .…”

“…The measured dielectric constant values are proportional to the water content in the epidermal tissue and are expressed as percentage of tissue water (0%‐100%; 0.5 mm measurement depth). Reliability of epidermal hydration measurements are also very high 42 …”

“Normal” TEWL‐how can it be defined? A systematic review

“…If normal reference TEWL values do not seem realistically achievable to calculate, these studies suggest that regulatory agencies may benefit from creating stricter microclimate and calibration guidelines. Additionally, even with trained and experienced researchers, reliability of TEWL measurements can often be low, so, it is recommended that experiments should use the average of multiple TEWL measurements to maximize reliability and minimize measurement error 51 …”

“…Additionally, even with trained and experienced researchers, reliability of TEWL measurements can often be low, so, it is recommended that experiments should use the average of multiple TEWL measurements to maximize reliability and minimize measurement error. 51 As previously mentioned, this review aimed to add to the review conducted by Akdeniz et al 5 Akdeniz et al 5 it is important to control for all extrinsic factors-those which are environmental and experimental-to the highest possible degree under standardized conditions. 2,3 Some important points must be considered in regards to TEWL variation.…”

Effects of loading and prophylactic dressings on the sacral and heel skin: An exploratory cross‐over trial

“…Therefore, the point measurements in this trial were considered appropriate. 30 Another possible limitation is the necessary dressing removal before skin measurements can be performed. When dressings are removed, there is a rapid change of skin parameters.…”