Is an easy and reliable diagnosis of localized neuropathic pain (LNP) possible in general practice? Development of a screening tool based on IASP criteria

Abstract

Background and objective:

Neuropathic pain (NP) is a common type of chronic pain in which 60% of patients present with localized symptoms. Early diagnosis of NP is often a challenge in primary care. Moreover, so far no standard diagnostic procedure for localized NP (LNP) is available. To help general practitioners, a screening tool was developed and evaluated.

Research design and methods:

The development of the screening tool was based on the grading system principles for NP proposed by the IASP, focusing on medical history and distribution of painful symptoms and sensory signs. It was tested by 31 general practitioners and evaluated against the NP diagnosis of three pain specialists as reference in a single center prospective study in Spain using a cohort study design including an adult population of chronic pain patients. This design avoids spectrum bias where the spectrum of disease is not correctly reflected in the study population.

Main outcome measures:

General practitioners rated usefulness, simplicity, and time requirements of the tool. Diagnostic accuracy was expressed by sensitivity, specificity, and positive and negative predictive values.

Results:

General practitioners consecutively screened 2079 chronic pain patients (mean age 60.7 ± 11.1 years, 69.9% female). Using the tool, 394 patients were diagnosed with LNP. Screening including sensory examination took 7 min (median). General practitioners rated the tool as useful (24/31; 77.4%) or very useful (7/31; 22.6%) for diagnosing LNP and facilitating clinical practice (30/31; 96.8%). Under daily practice conditions, sensitivity and specificity of the tool for detecting LNP was 46.7% and 86.6%, respectively.

Conclusions:

The proposed screening tool was shown to be easy and useful for detecting NP and LNP in chronic pain patients as a fast first assessment tool in primary care, thus facilitating the choice of a topical treatment.

Limitations and strengths:

The drop-out rate was high but was accounted for by using correction factors in the diagnostic accuracy calculations. A strength is the unselected chronic patient population: spectrum of disease correctly reflects day-to-day clinical practice and is not biased. Diagnostic accuracy of the tool therefore appears to be realistic.

Keywords::

• Diagnostic accuracy
• Evaluation
• General practitioner
• Localized neuropathic pain
• Pain diagnosis
• Primary care
• Screening tool

Transparency

Declaration of funding

The study was supported by Grünenthal GmbH, Aachen, Germany.

Declaration of financial/other relationships

G.M. has disclosed that he is a periodical consultant for Grünenthal. R.B. has disclosed that he is a consultant for Pfizer, Genzyme, Grünenthal, Mundipharma, Allergan, Sanofi Pasteur, Medtronic, Eisai, Lilly, Boehringer Ingelheim, Astellas, Novartis, Bristol-Myers Squibb, Biogenidec, AstraZeneca, Merck, and Abbvie. He is on the speakers’ bureau for Pfizer, Genzyme, Grünenthal, Mundipharma, Sanofi Pasteur, Medtronic, Eisai, Lilly, Boehringer Ingelheim, Astellas, Desitin, Teva Pharma, Bayer-Schering, and MSD, and received grants/research funding from Pfizer, Genzyme, Grünenthal, the German Federal Ministry of Education and Research, and the German Research Foundation. He is also a member of the IMI ‘European’ collaboration. G.C.-I. has disclosed that he was previously a consultant for Grünenthal. G.H. has disclosed that he received travel/accommodation expenses from Grünenthal for this project. V.M. has disclosed that he is a consultant for Grünenthal and has received sponsorship from Grünenthal. X.F. and D.S. have both disclosed that they received grants/research funding from Grünenthal. T.K. has disclosed that he is a consultant for Grünenthal and received travel/accommodation expenses from Grünenthal.

CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work. Peer reviewer 1 has no other relevant financial or other relationships to disclose; peer reviewer 2 has disclosed that he is on the speakers’ bureau for Merck.

Acknowledgments

The authors would like to thank all physicians participating in the study. Writing and editorial assistance was provided by Elke Grosselindemann and Birgit Brett. The study and the preparation of the manuscript were supported by Grünenthal GmbH, Aachen, Germany.

Previous presentation: Part of the manuscript data were presented as a poster at the XXI World Congress of Neurology (WCN), Vienna, Austria, 21–26 September 2013 (abstract 3145; Mick et al. J Neurol Sci 2013;333:e519-36).

List of investigators: General practitioners: A. Artuñedo, J.M. Badia, C. Burgos, J. Caballero, G. Casas, J. Claramunt, J.M. Cruz, M. Ferrer, X. Ferrer, X. Frías, A. Garcia, F. Gavilan, M. Gilaberte, M. Gomez, I. Gonzalez, A. Gregorio, A. Herrero, A. León, J. Mallafre, G. Martínez, I. Matey, M. Morales, N. Moran, X. Ordoñez, A. Oriol, B. Raspall, F. Salomon, T. Sayrol, N. Vazquez, A. Ventura, M. Vila. Pain specialists: E. Barceló, M. Pijoan, D. Sintes.