Validity and reliability of the Spanish version of the DN4 (Douleur Neuropathique 4 questions) questionnaire for differential diagnosis of pain syndromes associated to a neuropathic or somatic component.

Concepcion Perez,Silvia Diaz,Didier Bouhassira,Silvia Huelbes,Javier Rejas,Joaquin Insausti,Rafael Galvez

doi:10.1186/1477-7525-5-66

Abstract

BackgroundThis study assesses the validity and reliability of the Spanish version of DN4 questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component (non-neuropathic pain, NNP).MethodsA study was conducted consisting of two phases: cultural adaptation into the Spanish language by means of conceptual equivalence, including forward and backward translations in duplicate and cognitive debriefing, and testing of psychometric properties in patients with NP (peripheral, central and mixed) and NNP. The analysis of psychometric properties included reliability (internal consistency, inter-rater agreement and test-retest reliability) and validity (ROC curve analysis, agreement with the reference diagnosis and determination of sensitivity, specificity, and positive and negative predictive values in different subsamples according to type of NP).ResultsA sample of 164 subjects (99 women, 60.4%; age: 60.4 ± 16.0 years), 94 (57.3%) with NP (36 with peripheral, 32 with central, and 26 with mixed pain) and 70 with NNP was enrolled. The questionnaire was reliable [Cronbach's alpha coefficient: 0.71, inter-rater agreement coefficient: 0.80 (0.71–0.89), and test-retest intra-class correlation coefficient: 0.95 (0.92–0.97)] and valid for a cut-off value ≥ 4 points, which was the best value to discriminate between NP and NNP subjects.DiscussionThis study, representing the first validation of the DN4 questionnaire into another language different than the original, not only supported its high discriminatory value for identification of neuropathic pain, but also provided supplemental psychometric validation (i.e. test-retest reliability, influence of educational level and pain intensity) and showed its validity in mixed pain syndromes.

Highlights

This study assesses the validity and reliability of the Spanish version of Douleur Neuropathique 4 questions (DN4) questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component
The proportion of women and the mean age were significantly higher in the NNP group, but the two groups were homogenous in terms of educational level, pain intensity and analgesic treatment (Table 1)
Analysis of psychometric properties of the Spanish version of the DN4 questionnaire Internal consistency, inter-rater agreement and test-retest reliability Table 3 summarizes the values of the indicators related to reliability of the Spanish version of the DN4 questionnaire

Summary

Introduction

This study assesses the validity and reliability of the Spanish version of DN4 questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component (non-neuropathic pain, NNP). A series of recent studies [13,14,15,16,17,18] confirmed that chronic pain associated to a nerve lesion has specific clinical characteristics and showed that the combinations of selected symptoms and signs have a very high discriminant value for identification of this category of pain. This was the basis for the development and validation of screening tools in the form of simple questionnaires that could be helpful both in daily practice and clinical research. Despite the specificities associated to the description of chronic pain in different cultures, the symptom-based approach for diagnosis of neuropathic pain appears to have transcultural validity

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