The Douleur Neuropathique 4 questionnaire (DN4) is a simple and objective tool developed by the French Neuropathic Pain Group to screen for neuropathic pain.
This prospective observational study was undertaken in three hospitals to assess the validity of a Japanese translation of the DN4. We first translated the DN4 into Japanese using a forward–backward method. Pain specialists then examined patients independently and diagnosed them with neuropathic or non-neuropathic pain, according to the International Association for the Study of Pain definitions. The Japanese version of the DN4 questionnaire was then given to each patient.
Of 187 patients that met our inclusion criteria, 100 and 87 were diagnosed with neuropathic and non-neuropathic pain, respectively. The test–retest intra-class correlation coefficient (95% confidence interval) was 0.827 (0.769–0.870). Among patients with identical diagnoses of neuropathic or non-neuropathic pain, receiver-operating characteristic curve analysis revealed an area under the curve of 0.89. A cut-off point of equal or greater than 4 resulted in a sensitivity of 71% and specificity of 92%.
The Japanese version of the DN4 was found to be a helpful tool for discriminating between neuropathic and non-neuropathic pain.