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.