Validity and Reliability of the Arabic Adapted Version of the DN4 Questionnaire (Douleur Neuropathique 4 Questions) for Differential Diagnosis of Pain Syndromes with a Neuropathic or Somatic Component

Abstract

Verbal descriptors of pain can provide a basis for distinguishing neuropathic pain (NP) from pain of non-neuropathic origin. Much research has been undertaken to develop screening tools for this purpose. The DN4 questionnaire (NP in four questions), is one of theses tools, which was developed and validated in French in 2005. The purpose of this work is to provide an Arabic, culturally appropriate, reliable, and valid version of the DN4 interview questionnaire for the diagnosis of NP. A study was conducted consisting of two phases. In the first phase, translation and cultural adaptation of the questionnaire into dialectal Arabic according to international guidelines was accomplished. The final version was reviewed by an expert panel, then tested on a group of 30 patients. The second phase was the validation of the translated version. The analysis of psychometric properties included reliability (internal consistency, inter-rater agreement) and validity (receiver operating characteristics curve analysis and determination of sensitivity, specificity, and positive and negative predictive values). A sample of 170 subjects (129 women, 75%; age: 49.5 ± 12.4 years), 94 (55.3%) with NP and 76 with non-neuropathic pain was enrolled. The questionnaire was reliable (Cronbach's alpha coefficient: 0.63, inter-rater agreement coefficient: 0.96 [0.94-0.97]) and valid for a cut-off value ≥3 points, which was the best value to discriminate between NP and NNP subjects. This study represents the second validation DN4 in a language different from the original after the Spanish adaptation. These results support the high discriminatory value of the DN4 questionnaire for identification of NP.