Diagnostic accuracy and agreement of the face-to-face and online Ipswich touch test with 10-gram monofilament test for peripheral neuropathy screening among adult Filipinos with diabetes mellitus: A cross-sectional study at the University of Santo Tomas Hospital

Introduction: Ipswich touch test (ITT) is a simple, non-invasive test for screening risk of foot ulceration among patients with diabetes which shows similar agreement with monofilament test, however, this has not yet been verified in the local setting. Objectives: The primary objective of this study is to determine the diagnostic accuracy and agreement of face-to-face and online Ipswich touch test compared to 10-g monofilament test as reference standard. Methods: This was a cross-sectional, observational, analytical, prospective study which screened patients with diabetes for diabetic neuropathy using face-to-face, online Ipswich touch test compared to 10-g monofilament test. The primary endpoints were to determine the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and computed agreement to the 10-g monofilament test of both face-to-face and online ITT. Result: Two hundred twenty-one patients were included in the study. The sensitivity, specificity, positive and negative likelihood ratio of the online ITT, were 53.21%, 80.36%, 2.71 (95% CI: 1.79 to 4.10) and 0.58 (95% CI: 0.47 to 0.73), respectively. While the sensitivity, specificity, positive and negative likelihood ratio of the face-to face ITT, 74.31%, 73.21%, 2.77 (95% CI: 2.00 to 3.84) and 0.35 (95% CI: 0.25 to 0.49), respectively. The agreement between the 10-gram monofilament test and the face-to-face ITT was higher, with an observed agreement of 73.76% compared to the observed agreement for the 10-gram monofilament Test and the online ITT which was 66.97%. The overall accuracy of the online ITT in diagnosing peripheral neuropathy was calculated to be 66.97% (95% CI: 60.34% to 73.13%) while the overall accuracy of the F2F ITT was 73.76% (95% CI: 67.43% to 79.43%). Conclusion: The face-to-face ITT exhibited higher sensitivity and specificity, indicating a stronger diagnostic performance in detecting peripheral neuropathy among the study population. Diagnostic accuracy assessment showed that the face-to-face ITT demonstrated a moderate level of agreement with the 10-gram Monofilament Test, surpassing the online ITT, which only achieved a fair agreement level.