Grading the loss of sensation in diabetic patients: A psychometric evaluation of the rotterdam diabetic foot study test battery

Abstract

Introduction: Static- and moving 2-point discrimination (S2PD, M2PD), 10-g monofilaments- and tuning fork are validated outcome measures of clinical manifestations of diabetes-related neuropathy. No modern statistical techniques have been used to investigate how well these instruments combine to measure sensory loss. Methods: To grade sensory loss at the feet, we fitted parametric forms of Item Response Theory models to the data of these instruments. Results: The fit statistics indicate that the loss of sensation is gradable, with readily available instruments. S2PD and M2PD are lost first, followed by vibration sense, the 10-g monofilament and the ability to feel a cold stimulus. Conclusions: This test battery appears to provide sound measurement properties in a group of diabetic patients with diverse amounts of sensory loss. This approach may be used in clinical practice to grade sensory loss reliably and quickly, with instruments that are easy to use. Muscle Nerve 58: 559–565, 2018.