Evidence map›Paper›PMID 42605842›Full record

ArticlePain research & management2026

Experimental Pain Phenotypes in Individuals With Symptomatic Knee Osteoarthritis: A Neural Network-Based Clustering Approach.

Chiyoung Lee, Yeri Kim, Seoyoung Kim, Juyoung Park, Xiaoxiao Sun, Chen X Chen, C Kent Kwoh, Shen Liu, Dasol Ahn, Heewon Kim and 1 more

Registry-linked trialAbstract read
In one paragraph

Article in Pain research & management, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04375072 (Combination Therapy of Home-based Transcranial Direct Current Stimulation and Mindfulness-based Meditation for Self-management of Clinical Pain and Symptoms in Older Adults With Knee Osteoarthritis), which is not on this map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT04375072 nacompletednot on this map

Combination Therapy of Home-based Transcranial Direct Current Stimulation and Mindfulness-based Meditation for Self-management of Clinical Pain and Symptoms in Older Adults With Knee Osteoarthritis

TypeinterventionalSponsorUniversity of ArizonaRan2020 to 2025Enrolled208ConditionsOsteo Arthritis KneeArmsactive tDCS paired with active MBM, sham tDCS paired with active MBM, active tDCS paired with sham MBM, sham tDCS paired with sham MBM
3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Chiyoung LeeThe University of Arizona College of Nursing, Tucson, Arizona, USA.ORCID https://orcid.org/0009-0004-9523-501X
Yeri KimGlobal School of Media, College of Information Technology, Soongsil University, Seoul, Republic of Korea, ssu.ac.kr.ORCID https://orcid.org/0009-0009-6067-1483
Seoyoung KimGlobal School of Media, College of Information Technology, Soongsil University, Seoul, Republic of Korea, ssu.ac.kr.ORCID https://orcid.org/0009-0004-8352-4068
Juyoung ParkThe University of Arizona College of Nursing, Tucson, Arizona, USA.ORCID https://orcid.org/0000-0001-6737-3109
Xiaoxiao SunDepartment of Epidemiology and Biostatistics, The University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA.
Chen X ChenThe University of Arizona College of Nursing, Tucson, Arizona, USA.
C Kent KwohThe University of Arizona College of Medicine-Tucson, Tucson, Arizona, USA.ORCID https://orcid.org/0000-0001-5937-550X
Shen LiuPediatric Biostatistics Core, Children's Healthcare of Atlanta and Emory University, Atlanta, Georgia, USA.
Dasol AhnDepartment of Electrical and Computer Engineering, The University of Arizona College of Engineering, Tucson, Arizona, USA.
Heewon KimSchool of AI·Software, College of AI, Soongsil University, Seoul, Republic of Korea, ssu.ac.kr.ORCID https://orcid.org/0000-0001-7777-9823
Hyochol AhnThe University of Arizona College of Nursing, Tucson, Arizona, USA.ORCID https://orcid.org/0000-0002-9998-4876

Funding

Pain-related Brain Mechanisms for Pain Catastrophizing Behavior in Response to Home-based Mindfulness-based Meditation Paired with Transcranial Direct Current StimulationR01NR019051 · NINR · UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON · PI AHN, HYOCHOL · 2020 to 2025
$2.9M
Development of a Colorimetric Sensor for Detection of Cerebrospinal Fluid LeaksR44NS130769 · NINDS · DRINKSAVVY, INC. · PI HU, MIN · 2023 to 2024
$1.7M
HEAL National K12 Clinical Pain Career Development Award K12 NS130769NIH/NINR R01NR019051NINDS NIH HHS R44 NS130769NINR NIH HHS R01 NR019051
6 · The paper itself

Abstract

objectiveResearch has emphasized the "phenotyping" of knee osteoarthritis (OA) pain as a priority to effectively target therapies to individual patients. This study identified pain phenotypes based on experimental pain responses in patients with symptomatic knee OA using machine learning approaches and examined their associations with participant characteristics.

methodsIn this cross-sectional study, participants (N = 208; mean age = 67.64 ± 7.51 years) completed demographic, clinical, and psychological questionnaires, followed by a multimodal quantitative sensory testing (QST) battery. For phenotyping, we implemented a two-layer neural network-based k-means algorithm. Participant characteristics were compared across phenotypes using analysis of variance (ANOVA).

resultsFive phenotypes were identified, with marked differences across QST measures: (1) "high pressure pain sensitivity and impaired descending inhibition" (n = 86), characterized by average responses on most QST measures, particularly low pressure pain threshold (PPTh) and impaired conditioned pain modulation (CPM), (2) "high heat pain sensitivity" (n = 40), marked by the lowest heat pain thresholds and tolerances, (3) "low pain sensitivity" (n = 46), exhibiting low sensitivity across most QST measures, (4) "high pain sensitivity and impaired pain modulation" (n = 26), with the lowest PPTh, highest punctate mechanical pain, greatest temporal summation of mechanical pain, lowest CPM, and highest cold pain sensitivity, and (5) "pain-resilient" (n = 10), characterized by low sensitivity across most QST measures, along with the highest PPTh and highest CPM. Phenotypes differed significantly by sex, Kellgren-Lawrence score (index knee), pain severity (Numeric Rating Scale), and OA-related symptoms (Western Ontario and McMaster Universities Osteoarthritis Index), particularly physical function (p < 0.05).

conclusionsThis study identified distinct experimental pain phenotypes, each associated with unique demographic and clinical characteristics. These findings may inform the development of interventions tailored to specific pain profiles to improve pain management and functional outcomes in patients with symptomatic knee OA.

trial registrationClinicalTrials.gov identifier: NCT04375072.

Indexed as

Neural Networks, ComputerOsteoarthritis, KneePainPain ThresholdAgedCluster AnalysisClustering AlgorithmsCross-Sectional StudiesFemaleHumansMaleMiddle AgedPain MeasurementPhenotypeRandomized Controlled Trials as Topicexperimental painknee osteoarthritisphenotypequantitative sensory testing

Identifiers

PMID42605842
PMCPMC13479352

What OpenQuestion holds

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LicenceCC BY
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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.