The effect of probe placement on inter-trial variability when using the Cutometer MPA 580

There is limited data independently assessing the optimal use of the Cutometer MPA580. The purpose of this study is to test the hypothesis that the assessment of elastic recoil is significantly different when utilizing two different probe placement protocols. In protocol A, four trials were performed, in which the probe was removed from the skin between trials. In protocol B, the probe was not removed from the skin between trials. Fifty-four patients were enrolled and all completed the testing. When assessing elasticity (Ua/Uf), the inter-class correlation was 0.83 for protocol A and 0.48 for protocol B (p <0.001). There was no significant difference between individual trials for protocol A. Trial one of protocol B was significantly different (p < 0.001) than trials 2-4 for protocol B. Trial one of protocol B was not significantly different than any trial in protocol A. The results of this study suggest that the method in which a clinician performs repeated measure testing has a significant effect on the outcome measures when using the Cutometer. Removing the probe between trials appears to result in measures with higher reliability.