Diagnostic accuracy of an identification tool for localized neuropathic pain based on the IASP criteria

Abstract

Objective: Based on the clear neuroanatomical delineation of many neuropathic pain (NP) symptoms, a simple tool for performing a short structured clinical encounter based on the IASP diagnostic criteria was developed to identify NP. This study evaluated its accuracy and usefulness.

Methods: A case-control study was performed in 19 pain clinics within Spain. A pain clinician used the experimental screening tool (the index test, IT) to assign the descriptions of non-neuropathic (nNP), non-localized neuropathic (nLNP), and localized neuropathic (LNP) to the patients’ pain conditions. The reference standard was a formal clinical diagnosis provided by another pain clinician. The accuracy of the IT was compared with that of the Douleur Neuropathique en 4 questions (DN4) and the Leeds Assessment of Neuropathic Signs and Symptoms (LANSS).

Results: Six-hundred and sixty-six patients were analyzed. There was a good agreement between the IT and the reference standard (kappa =0.722). The IT was accurate in distinguishing between LNP and nLNP (83.2% sensitivity, 88.2% specificity), between LNP and the other pain categories (nLNP + nNP) (80.0% sensitivity, 90.7% specificity), and between NP and nNP (95.5% sensitivity, 89.1% specificity). The accuracy in distinguishing between NP and nNP was comparable with that of the DN4 and the LANSS. The IT took a median of 10 min to complete.

Conclusions: A novel instrument based on an operationalization of the IASP criteria can not only discern between LNP and nLNP, but also provide a high level of diagnostic certainty about the presence of NP after a short clinical encounter.

Keywords:

• Validity (epidemiology)
• sensitivity and specificity
• pain clinics
• diagnosis
• case-control studies

Transparency

Declaration of funding

Funding for the logistic aspects of this research was provided by Grünenthal Pharma, S.A. Grünenthal Pharma, S.A. did not have any direct corporate role in the design, analysis, interpretation of results, or preparation of the manuscript.

Declaration of financial/other relationships

The authors received funds from Grünenthal Pharma, S.A. for this research. V.M. received consultancy fees from Grünenthal Pharma, S.A. A.L. and A.E. have full-time positions at Grünenthal Pharma. J.V. received honoraria for drafting manuscripts for Grünenthal Pharma, Mundipharma, and Esteve, and receives consultancy fees from Grünenthal Pharma, Esteve, Amadix, Novartis, and Vivia Biotech.

Acknowledgments

The authors wish to thank all the clinical investigators for their contribution to this study in recruiting, assessing, and providing the data from the patients. The authors also acknowledge the contribution made by Raquel Jerez (Biostatistician) during the statistical analysis of the data. The authors also wish to thank patients who consented to participate and release their personal data for the scientific purposes of this research.