A New Simple SCreening Tool for Painful Diabetic Neuropathy (ACT) in Ecuador

Diabetic painful neuropathy is a cause of significant disability and sleep disturbance but may be undiagnosed in up to 80% of patients with diabetes. Various neuropathic pain (NP) questionnaires have good diagnostic utility but are impractical in resource-constrained and busy clinical settings. A simple sCreening Tool (ACT) was developed as a concise, patient-led tool to rapidly detect NP. This study evaluates the screening validity and psychometric properties of ACT compared with the DN4 questionnaire (reference standard).

We conducted an observational study employing clinic-based recruitment of patients with diabetes at a tertiary outpatient clinic in Guayaquil, Ecuador. All enrolled participants completed the ACT, DN4, and MNSI questionnaires during the study visit. MNSI was administered as part of the study to confirm the diagnosis of DPN using predefined cut-offs (MNSI-q ≥ 4 and MNSI-e ≥ 2.5). Time to completion, inter-item consistency, sensitivity, specificity, Youden's index, and the area under the receiver operating characteristic (ROC) curve were calculated for ACT using DN4 ≥ 4 as the criterion for NP.

Of the 300 participants (median age 63 years, diabetes duration 10 years), 65 (21.7%) had NP per DN4. Total ACTq+e (questionnaire+examination) yielded a cut-off score of ≥ 6 items as optimal, with area under the ROC curve 0.836, sensitivity 80.0% and specificity 75.7% for painful DPN. ACT demonstrated moderate internal consistency (Cronbach's alpha = 0.65) and was well received by patients and clinicians on face validity. The completion time for ACT was comparable to that of DN4.

The ACT tool is a rapid screening tool for identifying neuropathic pain in the busy clinic, with acceptable sensitivity and specificity compared to DN4. The brevity and ease of patient self-administration of ACT make it promising for integration into busy outpatient workflows to improve the diagnosis of painful DPN.