ADA 81st Symposium: Are Point-Of-Care Devices Beneficial in Diagnosing Diabetic Neuropathy?

There is not much evidence-based literature on point-of-care devices, yet they are commonly used for diagnosis of diabetic neuropathy. 

Point-of-Care Devices (PoCDs) are diagnostic tools that are simple, rapid, and are of “lab-quality.” They are used for management or diagnosis in clinical care settings. PoCDs include A1c testing devices and microalbuminuria tests. A PoCD teleophthalmology device sends images to the web for analysis by retinal specialists, and a report is sent in return to the referring clinician and patient with diabetes.

There are many ailments associated with uncontrolled diabetes, such as diabetic neuropathy. Neuropathy is a component cause for complications in late-stage diabetes (e.g., ulceration infection and amputation) and is a direct cause of pain and imbalance. Falls are more common in people with neuropathy, even before diagnosis. The most common type of diabetic neuropathy is called diabetic distal symmetrical polyneuropathy (DSP). DSP is a slowly progressive and primarily axonal injury to all peripheral nerves. In those with diabetes, peripheral neuropathy happens in 28.5% of people, and of those people, 11% are symptomatic. DSP starts in the toes and then goes to the legs and hands. Diagnosing DSP can be complicated. Therefore, some medical professionals believe a PoCD to confirm nerve injury would be a useful diagnostic tool.

In opposition, some medical professionals do not think this is a good idea because PoCD clinical trials have lacked both quantity and positive results for those done. The ADA even recommends that electrophysiological testing should not regularly be done for screening, instructing it only to be done when there are certain atypical features.

The accepted schematic for clinical tests and research tests is Frybeck’s’ conceptual framework. There are six levels required for a clinical trial. Level 1 needs the results of the study to be reproducible. Level 2 is for the investigation to have reasonable specificity, sensitivity, and positive predictive value. Level 3 change in diagnosis, level 4 changes in management, level 5 differences in patient outcomes, and level 6 covers cost-effectiveness. A systematic review of the literature revealed that all groups except for level 2 lack clinical tests.

When it comes to research tests, only levels 1 and 2 are required for research tests. This is believed to not be enough by many medical professionals. Additionally, Randomized Controlled Tests (RCTs) for diagnostic tests are lacking in quantity, and the existing RCTs have disappointing results. Of 140 diagnostic RCTs, only 18% were positive for effect on patient outcomes, and there was no correlation between patient outcomes and change in diagnostic tests.

A big issue is that there is no golden standard for neuropathy. It used to be NCS and then, for a while, switched to “signs, symptoms, and reflexes,” but there are many tests out there right now, and unfortunately, with minimal overlap of each other. Additionally, while each PoCD measures decently, most only measure one thing.

An unfortunate obstacle when considering the need to make and test more PoCDs is that historically even great products for patients have failed because they did not have a good business model. While they would have significantly lowered costs for patients, the companies making them would not get a profit. So, those PoCDs did not make it. A pressing limitation for current PoCDs is the lack of a gold standard. Furthermore, PoCDs are not being compared to what is currently recommended by the ADA. For example, the studies need to compare the current, and future, PoCDs to the ADA recommended tuning fork or monofilament. In conclusion, PoCDs are beneficial in diagnosing diabetic neuropathy. However, to be helpful in the future, screening needs to be held to a higher bar, better interventions are required, and the tests to come need to be better than the current tests on the market already recommended.

Practice Pearls:

• Interventions are lacking for peripheral neuropathy.
• There is a need for more thorough research on the point-of-care neuropathy devices; currently, most support studies come from a company making the PoCD.
• There is no gold standard in neuropathy, and a gold standard is needed.

Callaghan, Brian. “Could Point-of-Care Devices Prove Useful in the Diagnosis of Diabetic Neuropathy in Clinical Practice?” American Diabetes Association (ADA) Virtual 81^st Scientific Sessions. June 25. 2021, https://www.ada2021.org (Requires ADA Symposium login.)

Callaghan, Brian, et.al. Diabetic neuropathy: clinical manifestations and current treatments. The Lancet, June 2012.

Ashley Ball, PharmD Candidate, LECOM-School of Pharmacy