Validation of the Dutch version of the DN4 diagnostic questionnaire for neuropathic pain.

Difficulties in diagnosing neuropathic pain in routine clinical practice support the need for validated and easy-to-use diagnostic tools. The DN4 neuropathic pain diagnostic questionnaire aims to discriminate neuropathic pain from nociceptive pain, but needs clinical validation. A total of 269 patients with chronic pain in three pain clinics were included in the study of which 248 had analyzable data. The mean duration of pain was 4.9 years. The most frequent etiologies were posttraumatic (36%), (pseudo) radicular (14%), and mechanical back pain (12%). The mean intensity of pain at visit was 5.6 on a 0-10 scale. Hundred and ninety-six of 248 patients had an identical pain diagnosis from both physicians: 85 had neuropathic pain, 57 had nociceptive pain, and 54 had mixed pain. Among patients with identical diagnoses of neuropathic or nociceptive pain, using a receiver operating characteristic curve analysis, the area under the curve (AUC) was 0.81 for the DN4 7-item and 0.82 for the 10-item version. A cutoff point of 5/10 for the full questionnaire resulted in a sensitivity of 75% and a specificity of 79%, while a cutoff point of 4/7 for the partial questionnaire resulted in a sensitivity of 74% and a specificity of 79%. The items "brushing," "painful cold," and "numbness" were most discriminating. The DN4 is an easy-to-use screening tool that is reliable for discriminating between neuropathic and nociceptive pain conditions in daily practice. Item-specific scores provide important information in addition to the total score.