Accuracy and reliability of the Ipswich Touch Test in identifying Loss of Protective Sensation among diabetic patients.

The Ipswich touch test demonstrated a good diagnostic accuracy, with a sensitivity of 70.8%, specificity of 98.6%, and an area under the curve of 0.85 when compared to 10-g monofilament. Positive and negative predictive values were 94.4% and 90.8% respectively. The positive likelihood ratio was 49.82, and the negative likelihood ratio was 0.30. Interrater reliability, assessed with two raters in a subset of 93 participants, yielded a kappa of 0.88, indicating almost perfect agreement.