The role of amputative and non-amputative foot deformities severity in the risk for diabetic ulceration classification systems building: a cross-sectional and case-control pilot investigation.

Introduction: Foot deformities and amputations are parameters that have been studied as risk factors for diabetic foot ulceration (DFU). However, inclusion of "foot deformities" and "amputations" in a single, broad variable and with reference to the severity of these deformities, may better characterize subjects who are prone to develop DFU.

Methods: The objective of the study was the examination of amputative and non-amputative foot deformities severity as risk factor for DFU in relation with the other established risk factors. A cross-sectional and case-control study was conducted from October 2005 to November 2016. One hundred and thirty-four subjects with type 1 and 2 diabetes, with and without active foot ulcers, participated. A structured quantitative interview guide was used. Univariate logistic regression analysis for the literature's established risk factors was performed, as well as for two versions of the "amputative and non-amputative foot deformities severity" variable. Subsequently, multivariate logistic regression analysis (MLRA) for three models and receiver operating characteristic (ROC) curve analysis were carried out.

Results: From the MLRA, only PAD (peripheral arterial disease) was significant (OR 3.56, 95% CI 1.17-10.82, P=0.025 and OR 3.33, 95% CI 1.02-10.08, P=0.033). Concerning the ROC curve analysis of the models, the one with the three categories amputative and non-amputative foot deformities severity variable, had the greatest area under the ROC curve (0.763, P<0.001).

Conclusion: A united variable for lower extremity amputations and other foot deformities with reference to their severity, could be more helpful to the clinicians in identifying patients with diabetes at risk for foot ulceration.