In vitro differential diagnosis of clavus and verruca by a predictive model generated from electrical impedance
Journal
PLoS ONE
Journal Volume
9
Journal Issue
4
Pages
-
Date Issued
2014
Author(s)
Abstract
Background: Similar clinical appearances prevent accurate diagnosis of two common skin diseases, clavus and verruca. In this study, electrical impedance is employed as a novel tool to generate a predictive model for differentiating these two diseases. Materials and Methods: We used 29 clavus and 28 verruca lesions. To obtain impedance parameters, a LCR-meter system was applied to measure capacitance (C), resistance (Re), impedance magnitude (Z ), and phase angle (θ). These values were combined with lesion thickness (d) to characterize the tissue specimens. The results from clavus and verruca were then fitted to a univariate logistic regression model with the generalized estimating equations (GEE) method. In model generation, log ZSD and θSD were formulated as predictors by fitting a multiple logistic regression model with the same GEE method. The potential nonlinear effects of covariates were detected by fitting generalized additive models (GAM). Moreover, the model was validated by the goodness-of-fit (GOF) assessments. Results: Significant mean differences of the index d, R e, Z, and θ are found between clavus and verruca (p<0.001). A final predictive model is established with Z and θ indices. The model fits the observed data quite well. In GOF evaluation, the area under the receiver operating characteristics (ROC) curve is 0.875 (>0.7), the adjusted generalized R2 is 0.512 (>0.3), and the p value of the Hosmer-Lemeshow GOF test is 0.350 (>0.05). Conclusions: This technique promises to provide an approved model for differential diagnosis of clavus and verruca. It could provide a rapid, relatively low-cost, safe and non-invasive screening tool in clinic use. ? 2014 Hung et al.
SDGs
Other Subjects
analytical parameters; article; clavus; clinical article; controlled study; differential diagnosis; generalized estimating equation; human; human tissue; impedance; in vitro study; mathematical model; multivariate logistic regression analysis; prediction; receiver operating characteristic; skin disease; skinfold thickness; validation process; verruca vulgaris; area under the curve; Callosities; diagnostic use; pathology; statistical model; Warts; Area Under Curve; Callosities; Diagnosis, Differential; Electric Impedance; Humans; Logistic Models; ROC Curve; Warts
Type
journal article