A comparison of screening tools for the accurate diagnosis of peripheral neuropathy in type 2 diabetes

Abstract

Aim: To investigate and compare different subjective screening modalities recommended in the diabetic foot screening guidelines for detecting peripheral neuropathy in a primary care setting, and compare their results with the objective tool, the NC-Stat® DPN Check®. Research Design and Methods: A prospective non-experimental quantitative comparative study was conducted in Primary Health Centres. Sixty- three participants (mean age 54.5 years ± 10.5) who met the inclusion criteria and were living with Type 2 diabetes mellitus for at least 10 years were recruited using a convenience sampling method. The subjective tools utilized were the Semmes-Weinstein 10-g monofilament, 128-Hz traditional tuning fork (TTF), neurothesiometer and the O‟Brien 128-Hz electronic tuning fork (ETF). These tools were compared with the objective measure NC-Stat® DPN Check® for the detection of peripheral neuropathy. The NC-Stat device was chosen since it has been deemed by research as a reliable tool to detect peripheral neuropathy in its early stages. Each test was carried out bilaterally, therefore a total of 126 limbs were statistically analysed. Results: A significant difference was reported between all the screening tools when compared in the same group of participants (P < 0.05). The descending order of limbs classified as having „absent‟ sensation, from highest to lowest percentage is as follows: NC-Stat® DPN Check® (32.5%), ETF constant mode (23.8%), ETF descending mode (23%), TTF (20.6%), neurothesiometer (11.1%) and lastly the 10-g monofilament (4%). Further analysis comparing each subjective tool with the NC-Stat device within their respective categories revealed significant differences between the percentages of limbs with peripheral neuropathy. Conclusion: The findings have shown that some screening modalities are more sensitive to the diagnosis of DPN than others. This highlights the importance of using multiple screening tools to assess diabetic peripheral neuropathy (DPN) to gain a better understanding of the patient‟s neurological status. The findings also suggest the inclusion of objective tools such as the NC-Stat tool in diabetic foot screening assessments, as it may enhance the early detection of peripheral neuropathy. Additionally, considering that the subjective measures utilized in this study were all recommended by diabetic foot screening guidelines, the observed variations among these tools suggest a compelling case for change. With the advancements in technology and our evolving understanding of disease progression, it is suggested that these emerging screening tools may be incorporated into revised guidelines to ensure optimal and evidence-based care. Standardizing diagnostic criteria and identifying early biomarkers for nerve degeneration in DPN are crucial for optimal patient care. Further rigorous studies comparing screening tests with a gold standard tool are necessary to determine the most valid non-invasive screening modality utilized in a primary care setting which would reduce the false negative/positive result.