Validation of the Korean Version of the DN4 Diagnostic Questionnaire for Neuropathic Pain in Patients with Lumbar or Lumbar-Radicular Pain

PURPOSE: To evaluate the diagnostic value of the Korean version of the Douleur Neuropathique 4 (DN4) questionnaire and to validate this questionnaire in terms of psychometric properties in patients with chronic pain due to degenerative spinal disease. MATERIALS AND METHODS: The Korean version of the DN4 questionnaire, which was translated and linguistically validated by the MAPI Research Group, was tested on 83 patients with lumbar or lumbar-radicular pain. Test-retest reliability was evaluated in a subsample of 40 patients who completed two assessments with an interval of 2 weeks. Nociceptive pain and neuropathic component pain were diagnosed in 40 and 43 patients, respectively. RESULTS: The Cronbach's α coefficient of internal consistency was 0.819, and the test-retest intraclass correlation coefficient (3, 1) (95% confidence interval) was 0.813 (0.776–0.847) (n=40). The area under the receiver-operator characteristics curve was 0.953 (p<0.001), with 95% confidence interval between 0.869 and 0.990. The Korean version of the DN4 questionnaire showed a sensitivity of 100% and 87.1%, and a specificity of 88.2% and 94.1% at the cutoff value of 3/10 and 4/10, respectively, for discriminating neuropathic component pain. CONCLUSION: The present study demonstrated the good discriminatory power of DN4 between nociceptive pain and neuropathic component pain in patients with lumbar or lumbar-radicular pain.