Skin elasticity meter or subjective evaluation in scars: a reliability assessment

Abstract 

Various methods are available for evaluating the elasticity of scars. However, the reliability and validity of these methods have been sparsely examined. The aim of this study was to examine the reliability of the subjective evaluation of scar pliability, while at the same time testing the reliability of the measurements of a non-invasive suction device (Cutometer^® Skin Elasticity Meter 575) on scars. Four observers assessed 49 scar areas of 20 patients with a subjective assessment of pliability. Subsequently, each observer measured the scar areas with the Cutometer. The intraclass correlation coefficients (ICC) of the elasticity (Ue) and extension (Uf) parameters of the Cutometer were acceptable (r=0.76 and 0.74, respectively) when a single observer carried out the measurements. The subjective assessment of pliability needs to be completed by two or more observers to make the evaluation reliable (r=0.79). The concurrent validities between the subjective pliability–assessment and each of the Cutometer parameters were statistically significant and ranged from r = 0.29–0.53. The correlations between each of the Cutometer parameters were high and statistically significant (r⪖0.71). Conclusion: A single observer can reliably use the Cutometer for the elasticity measurements of scars. Furthermore, either Ue or Uf, instead of all five elasticity values provided by the Cutometer, can be adequately used for the elasticity measurements of scars. The subjective assessment of pliability of scars can only be assessed reliably when completed by two or more observers. The concurrent validity showed that all Cutometer parameters, except for visco-elasticity (Uv), and the subjective assessment of pliability measured the same characteristic of a scar.

Keywords:  Quantification of scar pliability, Reliability, Validity, Correlation