Psychometric Validity and Reliability of the Thai Version of the Neuropathic Pain Symptom Inventory.

OBJECTIVE The aim of this study was to evaluate validity and reliability of the Thai version of the Neuropathic Pain Symptom Inventory (NPSI-T) in Thai patients with neuropathic pain. Although the Thai version of Neuropathic Pain Symptom Inventory (NPSI-T) has been linguistically validated, the tool has to be psychometrically validated before applying to neuropathic pain patients in daily practice. MATERIAL AND METHOD Forty Thai patients with diagnosis of neuropathic pain were enrolled to the study and were evaluated by visual analog scale (VAS), the Thai version of Neuropathic Pain Diagnostic Questionnaire (DN4-T) and NPSI-T questionnaires. Four hours later the patients were asked to perform retest NPSI-T and to evaluate the understanding of each NPSI-T question. RESULTS The total score of NPSI-T questionnaire was statistically correlated to visual analog scale (VAS) (Spearman's correlation coefficient = 0.599, p < 0.001) and neuropathic pain diagnostic questionnaire (DN4-T) (Spearman's correlation coefficient = 0.695, p < 0.001). The reliability was determined by Intraclass correlation coefficient (ICC), an excellent interobserver agreement (ICC > 0.8) and good agreement (ICC 0.6-0.8) were presented in 30% and 70% of the questionnaire, respectively. CONCLUSION The study demonstrated validity and reliability of the NPSI-T for assessing the neuropathic pain in Thai patients.