Diagnostic Accuracy and Reliability of the Thai Version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale in Adults With Chronic Pain

Background: The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Pain Scale is a practical screening tool for identifying neuropathic pain (NP), but a validated Thai version has not been available. This study aimed to translate and cross-culturally adapt the LANSS into Thai and to evaluate its reliability and diagnostic performance in Thai adults with chronic noncancer pain. Methods: This prospective diagnostic accuracy and psychometric validation study was conducted at a tertiary pain clinic in Thailand. Using a quota-based 2-group design, 120 adults were enrolled, including 60 patients with predominantly NP and 60 with predominantly nociceptive pain based on an independent pain specialist diagnosis as the reference standard. The index test was the Thai LANSS, which was administered by a blinded investigator. Internal consistency, inter-rater reliability, test–retest reliability, and diagnostic performance were assessed. Results: The Thai LANSS showed acceptable internal consistency (Cronbach’s alpha = 0.725). Inter-rater reliability in a pilot phase (n = 10) was excellent (intraclass correlation coefficient [ICC] = 0.975, 95% confidence interval [CI]: 0.921– 0.994). Test–retest reliability over 2– 3 weeks (n = 30; 15 per group) was also excellent (ICC = 0.984, 95% CI: 0.941– 0.996). The Thai LANSS demonstrated good discriminatory performance, with an area under the receiver operating characteristic curve of 0.81 (95% CI: 0.75– 0.88). At the original cutoff of ≥ 12, sensitivity was 73.33% (95% CI: 62.14– 85.52) and specificity was 90.00% (95% CI: 82.40– 97.59). Conclusion: In this tertiary pain clinic sample, the Thai LANSS showed good discriminatory performance and strong reliability and may serve as a useful screening aid for NP rather than a stand-alone diagnostic tool. Further validation in broader, more heterogeneous Thai populations is warranted.