245: Development of a Multimodal Assessment Tool to Discriminate Pain Mechanisms Using Expert Consensus

Topic: Clinical Science
Subtopic: Non-specific to any diagnosis, Developing methodology/technology, Assessment and Measurement of Pain/Nociception, Quantitative Sensory testing (static and dynamic, e.g., HPT, PPT, CPM, TSP, offset analgesia)

Background and Aims: The International Association for the Study of Pain (IASP) defines three pain descriptors - nociceptive, neuropathic and nociplastic pain - but no gold-standard method exists to discriminate between them, and current grading systems do not permit identification of a predominant mechanism or the contribution of mixed mechanisms. Recent work derived mechanistically discriminative features using systematic review and expert consensus; however, disagreement remains regarding how these features should be operationalised into assessment tools. This study aimed to develop a multimodal tool to discriminate between pain descriptors by operationalising consensus-derived features into candidate measures and criteria using expert consensus.

Methods: An expert consensus study was conducted with the IASP Terminology Taskforce (N=26), allocated to nociceptive (n=10), neuropathic (n=10) and nociplastic (n=11) working groups. Ranked consensus-derived features were operationalised into candidate measures and criteria for three tool versions: self-report, simple clinical and advanced clinical/laboratory. A structured hybrid consensus framework integrated quantitative voting with structured use of disagreement. In Round 1, working groups proposed and refined measures, informed by targeted literature review and evaluated via online survey (≥70% agreement). In Round 2, consolidated items were reviewed in whole-panel meetings, with agreement in principle recorded and reasons for non-agreement documented.

Results: In Round 1 (N=26), consensus was achieved for 11/12 (92%) neuropathic items, 10/10 (100%) nociceptive items, and 7/11 (64%) nociplastic items. Disagreement most often reflected differences in theoretical interpretation, concerns regarding clinical feasibility, and ambiguity in operational definitions. Following refinement guided by structured disagreement, Round 2 (N=24/26; 92.3%) achieved consensus for all neuropathic (11/11) and nociceptive (8/8) measures and for 8/11 (73%) nociplastic measures. Three nociplastic measures did not reach consensus due to persistent concerns regarding discriminative validity and required refinement. Several features were merged to improve conceptual coherence. The final output comprised 29 operationalised items.

Conclusions: This study delivers a multimodal pain descriptor tool that operationalises mechanistic pain features across self-report, simple clinical and advanced clinical contexts. By explicitly structuring expert disagreement within the consensus process, the study achieved convergence on a set of operationalised measures in a highly contested domain. The tool provides a foundation for empirical validation of discrimination between pain descriptors and supports future development of mechanism-informed pain assessment in research and clinical practice.

References: None

Presenting Author: Jonathan N Davies
Submitting Author: Jonathan Davies

Senior Author: Paul W Hodges

IASP 2026 Global Year theme of Neuropathic Pain: No

• Brooke K Coombes: PhD - The University of Queensland
• Jonathan N Davies: PhD - The University of Queensland
• Paul W Hodges: PhD - The University of Queensland