Background: Confirmation of diabetic sensorimotor polyneuropathy (DSP) relies on standard nerve conduction studies\r\n(NCS) performed in specialized clinics. We explored the utility of a point-of-care device (POCD) for DSP detection by\r\nnontechnical personnel and a validation of diagnostic thresholds with those observed in a normative database.\r\nResearch Design and Methods: 44 subjects with type 1 and type 2 diabetes underwent standard NCS (reference method).\r\nTwo nontechnical examiners measured sural nerve amplitude potential (SNAP) and conduction velocity (SNCV) using the\r\nPOCD. Reliability was determined by intraclass correlation coefficients (ICC [2,1]). Validity was determined by Bland-Altman\r\nanalysis and receiver operating characteristic curves.\r\nResults: The 44 subjects (50% female) with mean age 56618 years had mean SNAP and SNCV of 8.068.6 mV and\r\n41.568.2 m/s using standard NCS and 8.068.2 mV and 49.9611.1 m/s using the POCD. Intrarater reproducibility ICC values\r\nwere 0.97 for SNAP and 0.94 for SNCV while interrater reproducibility values were 0.83 and 0.79, respectively. Mean bias of\r\nthe POCD was 20.163.6 mV for SNAP and +8.466.4 m/s for SNCV. A SNAP of #6 mV had 88% sensitivity and 94% specificity\r\nfor identifying age-and height-standardized reference NCS values, while a SNCV of #48 m/s had 94% specificity and 82%\r\nsensitivity. Abnormality in one or more of these thresholds was associated with 95% sensitivity and 71% specificity for\r\nidentification of DSP according to electrophysiological criteria.\r\nConclusions: The POCD demonstrated excellent reliability and acceptable accuracy. Threshold values for DSP identification\r\nvalidated those of published POCD normative values. We emphasize the presence of measurement bias ââ?¬â?? particularly for\r\nSNCV ââ?¬â?? that requires adjustment of threshold values to reflect those of standard NCS.
Loading....