A new application of the Rotterdam Diabetic Foot Study Test Battery: grading pedal sensory loss to predict the risk of foot ulceration

Abstract

AimsTo assess the relationship between the degree of loss of foot sensation at baseline and incidence of foot ulceration (DFU). MethodsDiabetic patients (n = 416) participating in the observational Rotterdam Diabetic Foot (RDF) Study were followed prospectively (median 955.5 days (IQR, 841.5–1121)). Subjects underwent sensory testing of the feet (39-item RDF Study Test Battery) at baseline and were assessed regarding incident DFU. Seven groups of incremental degree of sensory loss were distinguished, according to the RDF-39 sum score. Kaplan-Meier and regression analyses were used to determine the independent hazard of baseline variables for new DFU. Results40 participants developed DFUs. The mean incident rate of new-onset ulceration from study start was 4.5 (95%CI: 3.3 to 6.1) per 100 person-years, which increased significantly from 0 to 67.70 in the seven groups (p < 0.0005). Predictors for DFUs were higher RDF-39 score (aHR: 1.173, p < 0.0005) and kidney function (aHR: 1.022, p = 0.016). Prior DFU suggests increased mortality risk. ConclusionsThe degree of sensory loss at baseline was associated with progression to DFU during follow-up. Grading the loss of sensation using the RDF Study Test Battery may result in a more precise risk stratification compared to the use of the 10 g monofilament according to current guidelines.