The Maltese version of the DN4 questionnaire : initial validation to assess neuropathic pain in patients with chronic spinal or spinal-radicular pain

Abstract

Background: Neuropathic pain is frequently encountered in patients with spinal and spinal-related pain which needs specific treatment. Therefore, the objective of this study was to do an initial linguistic translation and validation of the Maltese DN4 questionnaire to diagnose neuropathic pain in this population.

Methods: The study was designed as a single-blinded, observational, prospective collected data and retrospective analysis. The English and French DN4 questionnaires underwent forward and backward translation, literal assessment and adaptation of the semantic equivalence into the Maltese language, followed by assessment of the Maltese DN4 during the initial patient assessment in patients who met the inclusion criteria.

Results: The total Maltese DN4 score obtained a Cronbach’s alpha of 0.735 therefore having satisfactory internal consistency. Test-retest using the Intraclass Correlation Coefficient (95% CI) ranged from 0.975 to 0.991 (p=0.000), while inter-rater agreement using Intraclass Correlation Coefficient (95% CI) ranged from 0.986 to 0.995 (p=0.000). Test-retest reliability yielded an intraclass correlation coefficient (95% CI) ranging from 0.975 to 0.991 (p < 0.001), while inter-rater reliability yielded an intraclass correlation coefficient (95% CI) ranging from 0.986 to 0.995 (p < 0.001). Both the English and the Maltese DN4 questionnaires obtained the same sensitivity and specificity values of 0.422 and 0.941 respectively, and a positive likehood ratio of 7.153 and a negative likehood ratio of 0.614, at a cutoff score of 4.

Conclusion: The results of this study support the transcultural internal consistency, inter-rater, test-retest reliability, validity of the Maltese DN4 questionnaire to differentiate between neuropathic and nociceptive pain in patients with chronic spinal and spinal-radicular pain. Therefore, this simple tool can be used both in daily clinical practice but also in the clinical research setting to quickly screen for neuropathic pain.