About

Hyochol Brian Ahn, PhD, APRN, ANP-BC, FAAN, is the Dean of the College of Nursing at the University of Arizona. He previously served as the Associate Dean for Research and was the founding director for the Brain Science and Symptom Management Center at Florida State University. His academic background includes a BE in Electrical Engineering from the University of Seoul, South Korea, and advanced degrees from the University of Florida, including an MS in Electrical and Computer Engineering, a BSN/MSN/PhD in Nursing, and an MS in Medical Sciences. Dr. Ahn combines expertise in nursing, medicine, and computer engineering, utilizing mobile and connected computer technology to optimize home-based nonpharmacological interventions and improve patient-centered outcomes in chronically ill and aging populations, especially among underserved groups. His research has been continuously funded since 2011, including an NIH/NINR R01 award as principal investigator, and has resulted in over 180 peer-reviewed publications and scientific presentations focused on healthcare technology, health equity, symptom science, and population health and wellness. Beyond academia, he has served on numerous grant review panels for institutions such as the NIH, Department of Defense, and Department of Veterans Affairs, and is the Editor-In-Chief of the Asian/Pacific Island Nursing Journal. As a nationally board-certified Nurse Practitioner and an Advanced Practice Registered Nurse, Dr. Ahn actively contributes to curriculum development, emphasizing problem-solving and team-based approaches, and incorporates online learning to enhance clinical exposure. He supports faculty in curriculum restructuring to meet accreditation standards and leads initiatives to expand nursing education programs, including the creation of innovative strategies for training highly skilled nurses. His dedication to advancing nursing education and gerontological nursing has been recognized with the Distinguished Educator Certificate in Gerontological Nursing from the National Hartford Center of Gerontological Nursing Excellence. Dr. Ahn's research and leadership focus on prevention, health promotion, population and community health, digital health, and aging, making significant contributions to the fields of healthcare technology and health equity.

Research topics

• Medicine
• Physical therapy
• Physical medicine and rehabilitation
• Psychology
• Internal medicine

Selected publications

• Neural and psychophysical predictors of treatment response to transcranial direct current stimulation and mindfulness-based meditation for knee osteoarthritis pain

  medRxiv · 2026-02-03

  articleOpen accessSenior author

  Abstract Aim We investigated the heterogeneity of treatment effects in transcranial direct current stimulation (tDCS) with mindfulness-based meditation (MBM) and within each individual study group (tDCS alone, MBM alone, and sham) among individuals with symptomatic knee osteoarthritis. We also explored participant characteristics underlying this heterogeneity. Methods This secondary analysis drew on a double-blind, randomized, sham-controlled, phase II, parallel-group trial in which 200 participants were assigned to one of four groups: (1) active tDCS + active MBM, (2) active tDCS + sham MBM, (3) sham tDCS + active MBM, or (4) sham tDCS + sham MBM. Participants received ten 20-minute tDCS sessions (active or sham) administered concurrently with MBM (active or sham). Latent class growth analysis was used to identify subgroups with distinct treatment response trajectories (responders vs. non-responders) based on changes in clinical pain (Numeric Rating Scale) from baseline to post-intervention. Generalized linear models were then applied to determine baseline factors associated with participants’ response classification, including demographic, clinical, and psychological characteristics; quantitative sensory testing battery; and pain-related cortical hemodynamic activity measured using functional near-infrared spectroscopy (fNIRS) in response to punctate and thermal stimuli. Results Responders in the active tDCS + active MBM and active tDCS + sham MBM groups demonstrated greater improvements in clinical pain from baseline to post-intervention than non-responders ( p < 0.001). In the active tDCS + active MBM group, greater cortical activation in the fNIRS channel S06-D06 of the left somatosensory cortex in response to punctate stimuli, identifying as white, and lower conditioned pain modulation (reflecting less efficient endogenous pain modulation), were significantly associated with being responders ( p < 0.05). In the active tDCS + sham MBM group, younger age and lower heat pain tolerance at the knee were significantly associated with being responders ( p < 0.05). No clear response patterns were observed in the remaining groups. Conclusion Factors underlying heterogeneity of treatment effects, including somatosensory cortical activation and pain modulatory profiles, may provide preliminary insights to inform the development of personalized neuromodulation (stimulation) protocols.

  PublisherDOI

• Predicting Heterogeneity of Treatment Effects to Transcranial Direct Current Stimulation for Knee Osteoarthritis Pain and Symptoms

  Clinical Journal of Pain · 2026-02-02

  articleSenior authorCorresponding

  OBJECTIVES: We planned to identifyied key predictors of the heterogeneity of treatment effects of transcranial direct current stimulation (tDCS) in individuals with knee osteoarthritis (KOA). METHODS: This is a secondary analysis of a randomized clinical trial involving 60 participants who underwent 15 daily sessions of 2-mA tDCS over 3 weeks. We applied group-based trajectory modeling to classify participants into distinct subgroups based on longitudinal KOA pain and symptom patterns from baseline to 3 months postintervention to examine differential responses to tDCS. Four learning-based classifiers-multilayer perceptron, ElasticNet, random forest, and gradient boosting decision trees-were then trained to predict the trajectory subgroups using demographic, clinical, and quantitative sensory testing data collected at baseline. Feature selection methods-f-regression, mutual information, and SHapley Additive exPlanations (SHAP)-were employed to identify the influential features. In addition, SHAP was used to analyze the correlation and impact of each feature on classification. RESULTS: Participants exhibited distinct response patterns to tDCS: high responders (low initial symptoms with significant improvement, n = 28) and low responders (high initial symptoms with minimal improvement, n = 32). The influential features included pain catastrophizing, conditioned pain modulation (CPM), and pressure pain thresholds (PPTh) at the trapezius. SHAP revealed that pain catastrophizing was the most influential feature. Greater pain catastrophizing, lower CPM, and lower PPTh were associated with a higher likelihood of being classified as low responders. CONCLUSION: Baseline assessments of pain catastrophizing, CPM, and PPTh may be used to stratify participants, optimize treatment allocation, or tailor stimulation parameters for individuals less likely to respond to tDCS protocols.

  PublisherDOI

• A randomized trial of a digitally delivered, home-based neuromodulation and mindfulness intervention for pain management in older adults with knee osteoarthritis

  npj Digital Medicine · 2026-03-31

  articleOpen accessSenior author

  Knee osteoarthritis (OA) is a major cause of chronic pain and disability in older adults, yet scalable home-based interventions remain limited, partly due to the lack of clinically effective digital solutions. This study is the first fully powered randomized, double-blind, sham-controlled trial to test a digitally delivered, home-based protocol combining transcranial direct current stimulation (tDCS) and mindfulness-based meditation (MBM) for knee OA pain. A total of 208 participants were randomized to active tDCS + MBM, active tDCS + sham MBM, sham tDCS + active MBM, or double sham; they completed ten 20-min sessions over 2 weeks. Knee pain intensity was measured at baseline, post treatment, and monthly for 3 months. Although both active tDCS groups improved, the difference between the combined tDCS + MBM intervention and tDCS alone was not statistically significant. Benefits were not sustained at 3 months. These findings offer the first evidence that a remotely supervised, digitally delivered tDCS + MBM intervention can rapidly reduce knee OA pain, supporting future personalized and extended treatment studies. Clinical trial registration: ClinicalTrials.gov NCT04375072 (registered May 7, 2020).

  PublisherOA PDFDOI

• Differential Association of Inflammation With Pain and Physical Function in Knee Osteoarthritis by Race Focusing on Non-Hispanic Whites and Asian Americans: Pilot Study in Florida

  Asian/Pacific Island Nursing Journal · 2026-01-13

  articleOpen accessSenior author

  Background: The current body of work has not yet addressed the potential racial differences in the relationship between systemic inflammation and knee osteoarthritis (OA) symptoms, including pain and physical function. Objective: This pilot study aimed to investigate this association specifically among non-Hispanic Whites and Asian Americans. Methods: We cross-sectionally analyzed 40 community-dwelling participants aged 50-70 years with self-reported knee OA pain, including 20 non-Hispanic Whites and 20 Asian Americans. Knee OA symptoms were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function subscales. The serum levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-10, as systemic inflammatory markers, were measured. Univariate and multivariable analyses, using stepwise linear regression models, were conducted to examine the correlation between these inflammatory markers and OA symptoms, with systematic adjustment for age. Results: In non-Hispanic Whites, the above inflammatory markers did not correlate with knee pain or physical function. In Asian Americans, bivariate analyses revealed that CRP and TNF-α levels were associated with worse WOMAC pain scores (r=1.325, P=.041; and r=2.418, P=.036, respectively), and CRP levels were also linked to worse WOMAC physical function scores (r=4.950, P=.035). Multivariate analyses confirmed the association of CRP levels with both worse WOMAC pain (β=1.328, P=.046) and physical function (β=4.974, P=.034) scores in Asian Americans. Conclusions: CRP may be a clinically relevant marker for knee OA symptoms, specifically in Asian Americans; however, caution is warranted owing to the exploratory nature of this study. Future research is set to benefit from leveraging a larger sample, incorporating additional inflammatory markers, and including racially diverse samples to validate and augment these findings.

  PublisherDOI

• Heterogeneity of treatment effects in transcranial direct current stimulation for knee osteoarthritis pain and symptoms

  PAIN Reports · 2026-03-10

  articleOpen accessSenior author

  Abstract Introduction: Although heterogeneity of treatment effects (HTEs) is commonly observed in clinical trials, it has received little attention in studies on transcranial direct current stimulation (tDCS). Objectives: This study identified the presence of HTE in tDCS treatment among participants with symptomatic knee osteoarthritis (KOA) and explored participant characteristics associated with this heterogeneity. Methods: This secondary analysis of a randomized clinical trial included 120 participants with symptomatic KOA who received 15 daily sessions of home-based 2-mA active or sham tDCS over 3 weeks. We used a multitrajectory analysis to identify distinct subgroups based on the longitudinal trajectories of KOA pain and symptoms from baseline to 3 months postintervention, capturing differential responses to tDCS. We then performed bivariate analyses to examine associations between trajectory groups and baseline demographic, clinical, and quantitative sensory testing characteristics. Results: In the active tDCS group, 2 distinct trajectories emerged: “low initial symptoms with significant improvement” (high responders; n = 28) and “high initial symptoms with minimal improvement” (low responders; n = 32). Compared to high responders, low responders had a higher body mass index, lower educational attainment, and greater pain catastrophizing (all P < 0.05). Low responders also exhibited lower pressure pain thresholds at both the medial knee and trapezius, higher punctate mechanical pain at both the patella and hand, lower conditioned pain modulation, and higher cold pain intensity at baseline (all P < 0.05). No notable HTE was observed in the sham tDCS group. Conclusion: Participants exhibited varying responses to active tDCS. The characteristics associated with HTE may inform the development of personalized stimulation protocols.

  PublisherDOI

• Heterogeneity of Treatment Effects in Transcranial Direct Current Stimulation for Knee Osteoarthritis Pain and Symptoms

  Scholar Commons (University of South Carolina) · 2026-04-01

  articleOpen accessSenior author

  Introduction: Although heterogeneity of treatment effects (HTEs) is commonly observed in clinical trials, it has received little attention in studies on transcranial direct current stimulation (tDCS). Objectives: This study identified the presence of HTE in tDCS treatment among participants with symptomatic knee osteoarthritis (KOA) and explored participant characteristics associated with this heterogeneity. Methods: This secondary analysis of a randomized clinical trial included 120 participants with symptomatic KOA who received 15 daily sessions of home-based 2-mA active or sham tDCS over 3 weeks. We used a multitrajectory analysis to identify distinct subgroups based on the longitudinal trajectories of KOA pain and symptoms from baseline to 3 months postintervention, capturing differential responses to tDCS. We then performed bivariate analyses to examine associations between trajectory groups and baseline demographic, clinical, and quantitative sensory testing characteristics. Results: In the active tDCS group, 2 distinct trajectories emerged: “low initial symptoms with significant improvement” (high responders; n 5 28) and “high initial symptoms with minimal improvement” (low responders; n 5 32). Compared to high responders, low responders had a higher body mass index, lower educational attainment, and greater pain catastrophizing (all P , 0.05). Low responders also exhibited lower pressure pain thresholds at both the medial knee and trapezius, higher punctate mechanical pain at both the patella and hand, lower conditioned pain modulation, and higher cold pain intensity at baseline (all P , 0.05). No notable HTE was observed in the sham tDCS group. Conclusion: Participants exhibited varying responses to active tDCS. The characteristics associated with HTE may inform the development of personalized stimulation protocols.

  PublisherDOI

• Pain-Evoked Functional Activation Combining Transcranial Direct Current Stimulation with Brain Imaging in Older Adults with Alzheimer’s Disease and Related Dementias

  Brain stimulation · 2025-01-01

  articleOpen accessSenior author

  Chronic pain is a prevalent and often underreported issue among older adults with Alzheimer’s Disease and Related Dementias (ADRD). Our study has shown that transcranial direct current stimulation (tDCS) combined with functional near-infrared spectroscopy (fNIRS) offers a novel approach to understanding and managing chronic pain in older adults with Alzheimer’s Disease and Related Dementias (ADRD). This study explored cerebral hemodynamic responses to pain stimuli in 40 participants with mild to moderate ADRD (mean age 73 years [SD = 7.87], 90% non-Hispanic White, 72.5% women), using tDCS to modulate pain-related cortical activity. Participants were randomly assigned to receive either active or sham tDCS. Pain thresholds were established using thermal stimuli, and fNIRS was employed to monitor hemodynamic changes in the prefrontal and somatosensory cortices.<br/>The study revealed significant hemodynamic differences between the active tDCS and sham groups. In the active group, pronounced hemodynamic responses were observed in the left and middle prefrontal areas, with significant activation noted in channels S4-D4 (oxygenated hemoglobin [HbO]: t = -2.25, p = .03; deoxygenated hemoglobin [HbR]: t = 2.53, p = .02) and S4-D6 (HbR: t = 2.22, p = .03). Additionally, strong correlations were found between fNIRS data and subjective pain measures, particularly in the left somatosensory region, where channels S8-D6 (r = .69, p = .001) and S8-D8 (r = .50, p = .02) showed significant positive correlations with NRS scores.<br/>These findings suggest that fNIRS effectively assesses pain-related cortical activation and that tDCS may enhance pain-related brain function and modulate pain pathways, leading to improvements in chronic pain perception. This pilot research highlights the value of integrating brain stimulation and neuroimaging techniques in advancing our understanding of pain processing in ADRD, signaling a potential shift in pain management strategies for brain disorders. Further investigation is warranted to fully explore these promising results.

  PublisherOA PDFDOI

• Cognitive Impairment and Pain Discrepancies in ADRD: Evaluating Pain Responses to tDCS Intervention

  Innovation in Aging · 2025-12-01

  articleOpen accessSenior author

  Abstract Assessing pain in individuals with Alzheimer’s disease and related dementias (ADRD) is challenging due to cognitive impairments that reduce the reliability of self-reported pain ratings, such as the Numerical Rating Scale (NRS). While caregiver-observed assessments, such as the Mobilization-Observation-Behavior-Intensity-Dementia-2 (MOBID-2), provide options, discrepancies between self-reported and observer-rated pain across cognitive impairment levels remain understudied. This study examines how cognitive function, stratified by the Montreal Cognitive Assessment (MoCA-30), influences pain reporting and response to transcranial direct current stimulation (tDCS), a nonpharmacological pain intervention. In this double-blind, randomized, sham-controlled trial, 40 older adults with ADRD and chronic pain (tDCS: n = 20, Sham: n = 20) received home-based tDCS (2mA, 20 minutes/session) or sham stimulation for five consecutive days. Pain intensity was assessed at baseline, post-intervention, and 1-, 2-, and 3-month follow-ups using NRS and MOBID-2. Participants were categorized into mild (18–25) and moderate (10–17) cognitive impairment groups. The sample included 29 females, 36 White participants, and 23 married individuals. Results showed that cognitive impairment significantly moderated discrepancies between NRS and MOBID-2 (F(4,35) = 3.364, p = .020, η² = .278). A significant Time × MoCA Severity interaction (p = .012) indicated that participants with lower MoCA scores demonstrated greater discrepancies in pain ratings. MOBID-2 consistently detected pain reduction following active tDCS, whereas NRS was less sensitive to these changes, particularly in those with greater cognitive impairment. These findings highlight the importance of cognitive-adaptive pain assessments and reinforce tDCS as a promising nonpharmacological intervention for pain management in ADRD.

  PublisherOA PDFDOI

• Part 2: Predicting heterogeneity of treatment effects to transcranial direct current stimulation for knee osteoarthritis pain and symptoms

  medRxiv · 2025-06-09

  preprintOpen accessSenior author

  Abstract Background Assessing the heterogeneity of treatment effects (HTE) is a fundamental aspect of precision medicine, which aims to predict the most optimal treatments based on participant-specific characteristics. This study seeks to identify key predictors of the HTE of transcranial direct current stimulation (tDCS) in individuals with symptomatic knee osteoarthritis (KOA) using machine-learning approaches. Methods We performed a secondary analysis of a randomized clinical trial involving 60 participants with symptomatic KOA. These participants underwent 15 daily sessions of 2-mA active tDCS (each session lasting 20 minutes) over a period of three weeks. Initially, we applied group-based trajectory modeling to classify participants into distinct subgroups based on longitudinal KOA pain and symptom patterns from baseline to three months post-intervention to examine differential responses to tDCS. A multi-layer perceptron classifier was then trained to predict the trajectory subgroups using demographic, clinical, and quantitative sensory testing data collected during baseline visits. Feature selection methods, including f-regression, r-regression, and SHapley Additive Explanations (SHAP), were employed to identify the influential features. Additionally, SHAP was used to analyze the correlation and impact of each feature on classification. Results Participants exhibited distinct response patterns to tDCS: high responders (individuals with low initial symptoms showing significant improvement, n = 28) and low responders (individuals with high initial symptoms showing minimal improvement, n = 32) to tDCS. The influential features included conditioned pain modulation (CPM), cold pain intensity, pressure pain thresholds (PPTh) at the medial knee and trapezius, and pain catastrophizing. SHAP analysis revealed that pain catastrophizing was the most influential feature. Additionally, lower CPM, higher cold pain intensity, lower PPTh, and greater pain catastrophizing were associated with a higher likelihood of being classified as low responders. Conclusion Our results contribute to the existing literature, suggesting that factors such as pain catastrophizing, peripheral and central pain sensitization, and individuals’ endogenous pain-inhibitory capacity should be carefully considered in future tDCS trials.

  PublisherOA PDFDOI

• Minimally important difference and responsiveness to change for numerical rating scale of menstrual pain severity: a psychometric study

  Frontiers in Pain Research · 2025-12-15 · 1 citations

  articleOpen access

  Background: Menstrual pain affects 45%-95% of reproductive-age females and increases the risk of other chronic pain conditions. Psychometrically sound measurement tools are essential for advancing research and clinical care in menstrual pain. Numerical rating scales (NRS) are widely used to measure pain severity. However, the minimally important difference (MID) and responsiveness to change of the NRS in the context of menstrual pain are not well understood. Understanding MID and responsiveness to change helps guide the evaluation of treatment efficacy and clinical decision-making. This study evaluated the MID and responsiveness to change in the NRS, ranging from 0 to 10, for menstrual pain severity. Methods: = 100) completed two surveys 24 h apart. In both surveys, we measured menstrual pain severity (worst, least, average menstrual pain in the past 24 h, and current menstrual pain) on a 0 (no pain) to 10 (extremely severe) NRS. MIDs were estimated using distribution-based approaches (standard error of measurement and effect size) and anchor-based approaches (using symptom interference and retrospective recall of change as anchors). Responsiveness to change was evaluated using standard response means and area-under-the-curve analysis. Results: < 0.001 for between-group comparisons). Area-under-the-curve estimates ranged from 0.66 to 0.70. Conclusions: The findings can inform the design and interpretation of studies testing interventions for menstrual pain, while also guiding clinicians in monitoring and adjusting treatment.

  PublisherOA PDFDOI

Recent grants

• Combination Therapy of Home-based Trans-cranial Direct Current Stimulation and Mindfulness-based Meditation for Self-management of Clinical Pain and Symptoms in Older Adults with Knee Osteoarthritis

  NIH · $455k · 2020–2025

Frequent coauthors

• Y. Raja Rampersaud

  University Health Network

  202 shared

• Michael G. Fehlings

  University of Toronto

  201 shared

• Charles G. Fisher

  Vancouver Spine Surgery Institute

  120 shared

• Marcel F. Dvorak

  Vancouver General Hospital

  113 shared

• Joel Finkelstein

  101 shared

• Brian Drew

  McMaster University

  82 shared

• R. Gandhi

  Arthritis Society

  81 shared

• J Roderick Davey

  Schroeder Arthritis Institute

  72 shared

Education

• Graduate Certificate, Aging and Geriatric Practice

  University of Florida

  2016

• MS, Medical Sciences

  University of Florida

  2015

• PhD, Nursing

  University of Florida

  2012

• MSN, Nursing (Adult Nurse Practitioner)

  University of Florida

  2009

• BSN, Nursing

  University of Florida

  2007

• MS, Electrical and Computer Engineering

  University of Florida

  2004

• BE, Electrical Engineering

  University of Seoul

  1997

Awards & honors

• Distinguished Educator Certificate in Gerontological Nursing…