Surreal illustration of nerve pathways and emotional nodes, representing the complexities of chronic neuropathic pain.

Untangling Neuropathic Pain: How the SF-MPQ-2 Subscale Can Help

Soraya Malik in Health & Wellness December 2025 • 4 min read.

"A deep dive into how a modified pain assessment tool is paving the way for better understanding and management of Complex Regional Pain Syndrome."

Complex Regional Pain Syndrome (CRPS) presents a unique challenge in pain management. CRPS can emerge following trauma, surgery, or even spontaneously, making its origins diverse and often mysterious. While some individuals experience a resolution of symptoms within the first year, many others face persistent pain and disability, significantly impacting their quality of life. Understanding and accurately measuring the neuropathic components of this pain is crucial for effective treatment and improved patient outcomes.

Recognizing this need, the Special Interest Group for CRPS of the International Association for the Study of Pain (IASP) convened a working group dedicated to developing recommendations for outcome measurement in clinical studies. Their aim was to establish a core set of measures that could be consistently used across different studies and international collaborations, fostering better understanding and advancements in CRPS research.

One of the tools considered by this group was the Neuropathic Qualities subscale (NeQ) of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ2). This subscale aims to capture the specific neuropathic features of pain, making it a valuable tool for researchers and clinicians alike. However, to ensure its reliability and validity, rigorous testing and analysis are essential. That’s exactly why researchers have been hard at work putting this tool to the test, and what we’re going to dive into today.

What This Study Adds to the Conversation About Chronic Pain

Surreal illustration of nerve pathways and emotional nodes, representing the complexities of chronic neuropathic pain.

A recent study delved into the psychometric properties of the SF-MPQ-2 Neuropathic Qualities subscale, specifically in individuals diagnosed with CRPS. The goal was to evaluate the subscale's validity, reliability, and responsiveness, ensuring it accurately captures the nuances of neuropathic pain experienced by these patients. The research team employed both classical psychometric evaluation and Rasch analysis—a statistical method that assesses how well the subscale measures the intended construct.

The study involved a secondary analysis of longitudinal data collected from 59 participants meeting the Budapest criteria for CRPS. These individuals were assessed at baseline, six months, and one year, providing a comprehensive dataset for analysis. The researchers examined various aspects of the NeQ subscale, including:

Item-total correlations: Measures the relationship between individual items and the overall score.
Unidimensionality: Assesses whether the subscale measures a single construct.
Convergent construct validity: Examines the correlation with other measures expected to relate to neuropathic pain.
Responsiveness: Evaluates the subscale's ability to detect changes in pain over time.
Rasch analysis: A statistical method to evaluate and address data fitting challenges.

The researchers found that the NeQ subscale demonstrated theoretical construct validity, with both item-total correlations and unidimensionality analyses supporting its use. All hypotheses regarding convergent construct validity were also supported. Moreover, the subscale exhibited responsiveness, demonstrating its ability to detect changes in pain intensity over time. Rasch analysis revealed that the data could fit the model, although some modifications were necessary to address disordered thresholds and local dependency.

The Road Ahead

This study offers preliminary support for the validity and responsiveness of the NeQ subscale in individuals with CRPS. Rasch analysis further endorses its use as a stand-alone measure for neuropathic features, albeit with substantial background data transformations. Replication with larger samples is recommended to increase confidence in these findings. By continuing to refine and validate tools like the SF-MPQ-2 NeQ subscale, researchers and clinicians can work together to improve the assessment and treatment of neuropathic pain, ultimately enhancing the lives of those affected by CRPS and similar conditions.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1093/pm/pny202, Alternate LINK

Title: Measurement Properties Of The Sf-Mpq-2 Neuropathic Qualities Subscale In Persons With Crps: Validity, Responsiveness, And Rasch Analysis

Subject: Anesthesiology and Pain Medicine

Journal: Pain Medicine

Publisher: Oxford University Press (OUP)

Authors: Tara L Packham, Debbie Bean, Malcolm H Johnson, Joy C Macdermid, Sharon Grieve, Candida S Mccabe, R Norman Harden

Published: 2018-10-20

Everything You Need To Know

What is the primary challenge in managing Complex Regional Pain Syndrome (CRPS)?

The primary challenge in managing Complex Regional Pain Syndrome (CRPS) lies in its diverse and often mysterious origins. It can arise after trauma, surgery, or even spontaneously. While some individuals recover within a year, many experience persistent pain and disability, significantly impacting their quality of life. Accurately measuring the neuropathic components of this pain is crucial for effective treatment and improved patient outcomes.

What is the purpose of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale (NeQ)?

The Neuropathic Qualities subscale (NeQ) of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) aims to capture the specific neuropathic features of pain. This makes it a valuable tool for both researchers and clinicians in understanding and assessing neuropathic pain, especially in conditions like Complex Regional Pain Syndrome (CRPS). Further testing ensures its reliability and validity.

How was the validity and reliability of the SF-MPQ-2 Neuropathic Qualities subscale assessed in the recent study?

The validity and reliability of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale were assessed using both classical psychometric evaluation and Rasch analysis. This involved examining item-total correlations, unidimensionality, convergent construct validity, and responsiveness using longitudinal data from 59 participants meeting the Budapest criteria for Complex Regional Pain Syndrome (CRPS).

What did the recent study reveal about the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale's ability to detect changes in pain over time?

The study demonstrated that the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale exhibited responsiveness, indicating its ability to detect changes in pain intensity over time in individuals with Complex Regional Pain Syndrome (CRPS). This is a crucial property, as it suggests the subscale can be used to monitor the effectiveness of treatments and interventions aimed at reducing neuropathic pain.

What are the next steps recommended to further validate the use of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale in assessing neuropathic pain?

The study recommends replication with larger samples to increase confidence in the findings regarding the validity and responsiveness of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale in individuals with Complex Regional Pain Syndrome (CRPS). Further refinement and validation of tools like the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Neuropathic Qualities subscale will improve the assessment and treatment of neuropathic pain.