Interobserver agreement in eliciting signs of peripheral neuropathy in patients with diabetes mellitus type 2

Objective: To determine the extent to which two different doctors agree on signs of peripheral neuropathy in patients with diabetes mellitus type 2. Methodology: In this observational study, patients with diabetes mellitus type 2 were selected by convenience sampling. Those with amputated feet, extensive skin ulceration not permitting clinical examination as well as unwilling patients were excluded from the study. Two doctors elicited three signs of peripheral neuropathy independently on the same day. Vibration sensation was checked over the tips of both great toes using a 128 Hz tuning fork. Light touch sensation was checked over plantar surfaces of both great toes with 10g Semmes-Weinstein monofilament. It was applied perpendicular to the skin surface for a second, using an amount of force that just buckled the monofilament. Both ankle jerks were also checked in a lying position with a reflex hammer. Responses to all the three tests were classified as being present bilaterally, present unilaterally or absent bilaterally. Results: A total of 105 patients were examined. Kappa values for vibration sensation, light touch sensation and ankle jerks were 0.330, 0.452 and 0.581, respectively. Conclusion: Suboptimal agreement between the two examiners calls for training prior to large scale studies, so as to reduce the variability in results.