Development and validation of a clinical model for predicting the severity of carpal tunnel syndrome.

This article focuses on developing a clinical composite index to assess the severity of carpal tunnel syndrome (CTS) prior to electrodiagnostic testing. Using data from 1,037 CTS patients, the index incorporates four key predictors: the numeric rating scale (NRS) for pain, thenar muscle weakness or atrophy (TW), cross-sectional area (CSA) of the median nerve measured by ultrasonography, and nocturnal pain (NP). The composite index, calculated as the average of scaled NRS and CSA plus binary NP and TW values, demonstrated high diagnostic accuracy (area under the curve = 0.85) and effectively stratified patients into mild, moderate, and severe CTS categories with low false-positive rates. This tool offers a non-invasive, cost-effective method to categorize CTS severity, potentially guiding clinical decision-making before conducting electrodiagnostic studies.