About

Roger B Fillingim, PhD, is a faculty member associated with UF Health. His professional focus includes research in pain, health, and behavior, contributing to the understanding of pain mechanisms and management. As a recognized expert, he is involved in academic and clinical activities that advance knowledge in these areas, supporting the mission of UF Health and its affiliated institutions.

Research topics

• Medicine
• Physical therapy
• Internal medicine
• Psychology
• Anesthesia
• Clinical psychology
• Physical medicine and rehabilitation
• Psychiatry
• Computer Science
• Human–computer interaction
• Gerontology
• Neuroscience

Selected publications

• Associations of Arterial Blood Pressure With Radiographic Knee Osteoarthritis and Pain Sensitivity in Middle‐Aged and Older Adults

  European Journal of Pain · 2026-02-01

  articleOpen access

  OBJECTIVE: High blood pressure (BP) often co-occurs with osteoarthritis (OA) and may influence pain sensitivity, potentially contributing to pain-pathology discordance. We hypothesized that higher BP would associate with reduced pain sensitivity and greater OA severity in adults with chronic knee pain. METHODS: A cross-sectional analysis of 213 community-dwelling adults (44-78 years) with chronic knee pain was conducted. Hypertension was defined by diagnosis or antihypertensive use; others were normotensive. Systolic, diastolic, pulse (PP), and mean arterial (MAP) BP were measured. Quantitative sensory testing assessed pressure/thermal pain sensitivity, temporal summation (TS), and conditioned pain modulation (CPM). Radiographic knee OA (rKOA) was graded using the Kellgren-Lawrence scale. Models adjusted for race, age, BMI, site, and diabetes. RESULTS: Blood pressure-pain associations were moderated by sex and hypertensive status, observed only in normotensive individuals. Among normotensive males, each 10 mmHg increase in BP was associated with reduced pressure pain sensitivity (β [95% CI]: systolic -0.21 [-0.42, -0.002]; diastolic -0.36 [-0.68, -0.05]; MAP -0.31 [-0.59, -0.03]; all p < 0.05) but greater odds of late-stage rKOA (AOR [95% CI]: systolic 1.70 [1.07, 2.70]; MAP 2.10 [1.10, 4.01]). Among normotensive females, temporal summation of mechanical pain increased with higher BP (β [95% CI]: systolic 0.14 [0.01, 0.27], p = 0.027; PP 0.20 [0.02, 0.38], p = 0.026). No significant associations were observed for heat/cold pain sensitivity, TS of heat pain, or CPM. DISCUSSION: Elevated BP was associated with hypoalgesia and more severe rKOA severity in normotensive males. In normotensive females, elevated BP showed greater pain facilitation but not rKOA severity. Together, these sex-specific findings suggest BP as a vascular factor contributing to pain-pathology mismatch in OA. SIGNIFICANCE STATEMENT: Associations between arterial blood pressure and pain in older adults with knee pain were found to be sex- and hypertension-dependent, primarily evident in normotensive individuals. Elevated blood pressure was associated with reduced mechanical pain sensitivity but greater radiographic OA in normotensive males; normotensive females showed enhanced pain facilitation without increased OA severity. These findings support arterial pressure as a shared vascular factor in pain-pathology mismatch and highlight the importance of incorporating cardiovascular markers into chronic pain phenotyping and interpretation.

  PublisherOA PDFDOI

• Association Between Different Analgesic Use and Hypertension Among Medicare Beneficiaries With Osteoarthritis

  Journal of the American Geriatrics Society · 2026-03-15

  article

  BACKGROUND: In older adults with osteoarthritis (OA) and hypertension (HTN), analgesic use may elevate blood pressure and cardiovascular risk. Whether comorbid HTN influences initial analgesic choice remains unclear; we examined initial analgesic use in Medicare beneficiaries with incident OA, comparing those with and without HTN. METHODS: We conducted a retrospective cohort study using 2011-2022 nationally representative Medicare beneficiaries (≥ 65 years) with incident OA who initiated an analgesic within 30 days of diagnosis and had continuous enrollment for ≥ 365 days prior through ≥ 30 days post-index. Patients with baseline HTN were classified as OA + HTN; others as OA-only. We assessed overall analgesic trends using the Cochran-Armitage test and evaluated differences by HTN status using logistic regression with year as an interaction term. For stratified analyses by joint type, we applied weighted logistic regression. RESULTS: Among 179,033 beneficiaries (mean age 75 ± 7.3 years; 62.7% women; 80.7% White), 57.1% had baseline HTN. Overall, the most commonly initiated analgesic classes were intra-articular injections (30.3%), and oral NSAIDs only (28.2%). Notable changes from 2012 to 2022 were increase in topical NSAIDs use (3.1%-5.7%) and decrease in opioid combination use (25.4%-13.9%), with no significant trend differences by HTN status. In joint-specific analyses, OA + HTN versus OA-only showed no differences in odds of initiating oral opioids (OR: 0.97, 95% CI: 0.92-1.03), intra-articular injections (OR: 1.01, 95% CI: 0.96-1.07) or topical NSAIDs (OR: 0.88, 95% CI: 0.78-1.01) versus oral NSAIDs. CONCLUSION: Baseline HTN did not influence the choice of initial analgesic in incident OA patients. Safer, evidence-based alternatives are needed for older adults with comorbid HTN.

  PublisherDOI

• Clinical Outcomes Associated with Concomitant Use of CYP3A4-Inducing Anticonvulsants and Opioids in Older Nursing Home Residents—A Target Trial Emulation Study

  SSRN Electronic Journal · 2026-01-01

  preprintOpen access
  PublisherDOI

• Beta Blocker Use and Total Knee Arthroplasty Among United States Medicare Beneficiaries

  Pharmacoepidemiology and Drug Safety · 2026-05-01

  article

  BACKGROUND/OBJECTIVES: Preclinical evidence suggests beta blockers may reduce cartilage degradation and delay knee osteoarthritis (OA) progression. While beta blockers are widely used in patients with hypertension, their potential role in preventing total knee arthroplasty (TKA) is unclear. Therefore, we assessed the association between beta blocker use and TKA in knee OA patients with hypertension. METHODS: We conducted a nested case-control study using a nationally representative sample of Medicare beneficiaries with newly diagnosed knee OA and prevalent hypertension from 2011 to 2020. Beneficiaries who underwent TKA were defined as cases, while those without TKA were defined as controls. Cases and controls were matched at a 1:4 ratio based on pre-specified criteria using incident density sampling. We measured binary (exposed/unexposed) and cumulative exposure of beta blockers during 6 months before TKA using total standardized daily doses (TSDD) for each patient, categorized as unexposed (0), < 1-200, 201-400, 401-600, 601-900, > 900. Confounding was addressed using propensity score adjustment and stratification for the binary exposure and direct covariate adjustment for cumulative exposure in conditional logistic regression models. RESULTS: We included 30 338 beneficiaries with TKA and 106 145 matched controls. The mean age (SD) was 74.4 (5.5) years, and 67.1% were women in both groups. There was no significant association between beta blocker use and odds of TKA (adjusted OR [aOR] 1.01; 95% CI, 0.97-1.02) compared with unexposed individuals. Smilarly, no cumulative exposure category was associated with TKA risk (TSDD: < 1-200 [aOR, 1.01; 95% CI,0.97-1.04]; TSDD: 201-400 [aOR 1.00; 95% CI, 0.96-1.05]; TSDD: 401-600 [aOR, 1.02; 95% CI, 0.96-1.08]; TSDD: 601-900 [aOR 0.94; 95% CI, 0.87-1.00]; and, TSDD: > 900 [aOR 0.99; 95% CI, 0.91-1.08]), compared with the unexposed group. CONCLUSION: We found no evidence to support that beta blocker exposure reduces the likelihood of TKA.

  PublisherDOI

• CYP2D6-Guided Opioid Management and Postoperative Pain Control

  JAMA Network Open · 2026-02-20 · 1 citations

  articleOpen access

  Importance: Individuals with genetic variation that results in absent (poor metabolizers) or reduced (intermediate metabolizers) cytochrome P450 2D6 (CYP2D6) enzyme activity have lower concentrations of highly potent active metabolites of tramadol, hydrocodone, and codeine and are thus at increased risk for inadequate pain control. Objective: To determine the effect of CYP2D6-guided opioid prescribing on postoperative pain and opioid use. Design, Setting, and Participants: This open-label randomized clinical trial enrolled participants from surgery clinics at 8 US health systems. Individuals undergoing a planned surgery anticipated to cause postoperative pain for at least 7 to 10 days were enrolled from March 2021 to September 2023, with follow-up concluded in March 2024. Intervention: Participants in the CYP2D6-guided arm underwent CYP2D6 genotyping before surgery, with recommendations to avoid tramadol, hydrocodone, and codeine for postoperative pain in CYP2D6 poor and intermediate metabolizers, as defined by genotype and use of CYP2D6 inhibitors. Participants in the control arm had usual pain management. Main Outcomes and Measures: The primary outcome was the 10-day Silverman integrated analgesic assessment (SIA) score, a rank-based composite measure of average pain intensity on a 10-point scale, with higher scores indicating greater pain and opioid use (in morphine milligram equivalents [MMEs]). Secondary end points included individual components of the primary outcome and concordance between metabolizer phenotype and prescribed opioid 10 days after surgery. The primary analysis compared outcomes between poor and intermediate metabolizers in the CYP2D6-guided arm vs the control study arm. The analytical population comprised the subset of intent-to-treat participants with an actionable phenotype who completed surgery. Results: Of 1602 participants enrolled, 351 (mean [SD] age, 62 [13] years; 237 [68%] female) had a CYP2D6 poor or intermediate metabolizer phenotype, proceeded to surgery, and were randomized to the CYP2D6-guided (n = 176) or control (n = 175) study arm. The most common procedures in the actionable population were total knee (177 [50%]) and total hip (97 [28%]) arthroplasties. Concordance between postsurgical opioid treatment and CYP2D6 phenotype was 64% (n = 112) in the CYP2D6-guided arm and 27% (n = 47) in the control arm (difference, 37 [95% CI, 27-46] percentage points; P < .001). At 10 days, the mean (SD) SIA score was 1.4 (95.9) in the CYP2D6-guided arm and -1.4 (93.1) in the control arm (difference, 2.8 [95% CI, -18.3 to 23.8]; P = .80). Mean (SD) numeric pain intensity rating (5.2 [2.2] and 5.1 [2.3]), overall opioid use (13.7 [14.9] and 13.2 [14.7] MME/d), and other secondary end points did not differ between the CYP2D6-guided arm and the control arm. Conclusions and Relevance: In this randomized clinical trial of CYP2D6-guided postoperative opioid prescribing, there were significant prescribing changes in CYP2D6 poor and intermediate metabolizers but no differences in pain control compared with usual care. The data do not support a role for CYP2D6-guided opioid therapy in the contemporary postoperative setting of multimodal pain management. Trial Registration: ClinicalTrials.gov Identifier: NCT05966129.

  PublisherOA PDFDOI

• Beyond nociception: rethinking pain in ovarian endometriosis a pilot study

  Frontiers in Pain Research · 2026-03-11

  articleOpen accessSenior author

  Background Endometriosis affects 1 in 10 women, is the most common cause of chronic pelvic pain, classically known for its nociceptive pain mechanisms. Medical therapies have limited efficacy, prevent pregnancy, and can be poorly tolerated in over 30% of cases. Meanwhile, surgical management can be associated with up to 37% of pain persistence, and over 45% undergo repeat surgery within five years. Objective To characterize differing pain profiles between women with ovarian endometriosis and those with other benign ovarian cysts. Study design Prospective observational cross-sectional clinical study between surgical ovarian endometriosis and control individuals. The primary outcome was to detect differences in the presence of nociplastic pain among the two groups using the Fibromyalgia (FM) Survey Score. Results 33 participants were approached from July 2024 to October 2024. Twelve participants with ovarian endometriosis and eight control participants with non-endometriosis ovarian cysts were enrolled. There was a statistically significant difference in the prevalence of elevated FM Survey score between the endometriosis group and controls (41.7% vs. 0%, p = 0.045). Further significant differences were identified in total FM Survey scores, Brief Pain Inventory pain severity, visual analog pain scores for dysmenorrhea, chronic pelvic pain, dyschezia, dysuria, dyspareunia, and evidence of adenomyosis. Conclusion Ovarian endometriosis, despite its well-known inflammatory pain characteristics, is associated with elevated FM survey scores, which may suggest nociplastic centrally mediated pain mechanisms.

  PublisherOA PDFDOI

• Pain and treatment outcomes after initiating methadone vs buprenorphine among medicare patients with opioid use disorder and comorbid chronic pain: A target trial emulation

  PLoS Medicine · 2026-03-26

  articleOpen access

  BACKGROUND: Methadone and buprenorphine, effective treatments for opioid use disorder (OUD), also provide analgesia for managing pain, which is commonly experienced by patients with OUD. Limited population-based evidence exists comparing pain-related and treatment outcomes for methadone versus buprenorphine among patients with OUD and comorbid pain. The study aims to examine pain-related and treatment outcomes among Medicare patients with comorbid pain and OUD who initiated methadone or buprenorphine. METHODS AND FINDINGS: We conducted a retrospective cohort study with target trial emulation using the 100% Medicare data from 2020 to 2023. Participants included patients with comorbid chronic pain and OUD who initiated methadone or buprenorphine. The key dependent variables were pain-related outcomes that included hospitalization and emergency department (ED) visit due to pain, and treatment outcomes that included opioid overdose and all-cause mortality. Outcomes were assessed 1 year following treatment initiation. Intention-to-treat and per-protocol analyses were conducted to estimate incidence rate ratios (IRRs) for pain-related outcomes and opioid overdose and hazard ratios (HRs) for all-cause mortality. For each outcome, we also calculated the adjusted risk difference (aRD) between the methadone and buprenorphine groups. We identified 49,727 eligible Medicare patients (mean [SD] age, 59.0 [11.6] years; 24,538 [49.3%] female and 25,189 [50.7%] male). Of the identified patients, 16,174 (32.5%) initiated methadone solely administered at opioid treatment programs, and 33,553 (67.5%) initiated buprenorphine primarily prescribed at office-based clinics. Compared with buprenorphine, initiation of methadone was associated with lower adjusted incidence rates of pain-related hospitalization (IRR, 0.64 (95% CI [0.58, 0.70]; P < .001); aRD, -7.2 (95% CI [-8.8 to -5.7]) per 1,000 person-years) and ED visit (IRR, 0.87 (95% CI [0.82, 0.92]; P < .001); aRD, -10.2 (95% CI [-14.4, -5.9]) per 1,000 person-years) in per-protocol analyses, with no difference in opioid overdose (IRR, 1.02 (95% CI [0.93,1.10]; P = .72); aRD, 0.33 (95% CI [-1.5, 2.1]) per 1,000 person-years) and all-cause mortality (HR, 1.06 (95% CI, [0.81-1.39]; P = .66); aRD, 1.1 (95% CI [-1.3, 1.0]) per 1,000 person-years) rates. Similar results were observed in intention-to-treat analyses. Main study limitations included unmeasured confounders and limited generalizability. CONCLUSIONS: This population-based cohort study of Medicare patients with comorbid chronic pain and OUD found that methadone administered at opioid treatment programs is associated with reduced hospitalizations and ED visits for pain-related visits while offering treatment outcomes similar to buprenorphine primarily prescribed at office-based clinics. The favorable pain-related outcomes in patients with methadone should be interpreted with caution, as the finding may reflect differences in the underlying patient population, treatment dosing practices, pharmacological properties, and treatment practice settings, which cannot be measured in Medicare data and merit further investigations.

  PublisherDOI

• Circulating cellular senescence biomarkers in persons with chronic knee osteoarthritis pain: An exploratory study

  Molecular Pain · 2026-02-01

  articleOpen access

  The senescence-associated secretory phenotype (SASP) contributes to tissue degeneration and inflammation, yet its role in osteoarthritis (OA)-related pain remains poorly understood. We hypothesized that circulating SASP markers would be associated with distinct OA-pain phenotypes, defined by pain impact and radiographic OA (ROA) severity. A subset of middle-to-older-aged adults (45–85 years) from a larger multi-site study ( n = 169) self-reported pain impact – defined as the extent to which pain interferes with daily functioning – and underwent knee radiography and blood collection. Hierarchical cluster analysis was used to empirically identify OA-pain phenotypes based on combined pain impact and Kellgren-Lawrence (KL) grade. Plasma levels of four SASP markers (GDF-15, activin-A, Osteopontin (OPN), and IL-15) were quantified from whole blood samples. Among 169 participants, 35.5% reported high-impact chronic knee pain and 27.8% exhibited moderate-to-severe radiographic OA. Cluster analysis identified distinct ROA-pain phenotypes. GDF-15 levels were significantly elevated in non-Hispanic White females with early ROA and high-impact pain, with race- and sex-dependent differences. Activin-A levels were higher in non-Hispanic Black participants without pain or ROA and varied by sex in early ROA/low-impact pain phenotypes. Osteopontin levels were elevated in males compared to females within the same phenotype group. IL-15 levels showed no association with ROA-pain phenotypes but were higher in males and positively correlated with age. SASP factors, particularly GDF-15, Activin-A, and Osteopontin, demonstrated race- and sex-dependent associations with OA-pain phenotypes. These findings underscore the importance of demographic context in OA pathophysiology and support further investigation into SASP factors as potential biomarkers and therapeutic targets for OA-related pain.

  PublisherDOI

• Beliefs about pain and lived experience of chronic pain among Korean Americans in the community: A qualitative study

  Journal of Pain · 2026-05-03

  articleSenior author
  PublisherDOI

• Transforming mentor practices and identity through structured research mentor training: “I am as a mentor still under construction”

  International Journal of Mentoring and Coaching in Education · 2025-10-17

  article

  Purpose This study examines the impact of structured research mentor training, based on the CIMER programme, on mentors' practices and identities in higher education, focusing on transformative learning as experienced by mentors and observed by mentees (Illeris, 2014). Design/methodology/approach Semi-structured interviews were conducted with ten Mentor Academy alumni and nine of their mentees. Inductive thematic analysis (Braun and Clarke, 2006) was used to identify broader themes based on participants' insights. Findings The analysis revealed that research mentor training supported identity development through cognitive, emotional and social learning dimensions (Illeris, 2007). Mentors gained tools and structure, deepened self-awareness, and adopted more intentional, reflective practices. They became more emotionally available and attentive to mentees' needs, while mentees reported feeling valued and supported. Reciprocal learning and community building were central, fostering a growth mindset (Dweck, 2006). Findings also speak to conceptual questions about the nature of mentor identity and its relationship to academic roles. Practical implications Findings emphasize that structured research mentor training fosters cognitive, emotional, and social learning (Illeris, 2007, 2014). Mentoring should be positioned as a developmental, identity-forming academic practice (McAlpine and Åkerlind, 2010), supported by ongoing reflection and community. Recognizing it as scholarly work can strengthen institutional culture and mentor commitment (Maxwell et al., 2024). Originality/value Beyond improving mentoring practices, findings highlight mentor training as a site of evolving academic identity. The findings contribute novel insights into the underexplored intersection of research mentoring and identity formation, positioning mentoring not only as a professional skill but also as a dynamic space where academic roles and self-conceptions are redefined.

  PublisherDOI

Recent grants

• NIH Grant R01AG033906

  NIH · $4.5M · 2014

• Ethnic Differences in Responses to Painful Stimuli

  NIH · $1.1M · 2009–2019

• NIH Grant R29DE012261

  NIH · $499k · 2002

• University of Florida Resource Center for Minority Aging Research

  NIH · $4.1M · 2018–2024

• NIH Grant R01NS042754

  NIH · $2.4M · 2008

Frequent coauthors

• Roland Staud

  University of Florida

  245 shared

• William Maixner

  DaVita Clinical Research (United States)

  189 shared

• Yenisel Cruz‐Almeida

  University of Florida

  165 shared

• Toni L. Glover

  Oakland University

  159 shared

• Joseph L. Riley

  Copenhagen Business School

  159 shared

• Burel R. Goodin

  Washington University in St. Louis

  145 shared

• Kimberly T. Sibille

  University of Florida

  143 shared

• Luda Diatchenko

  139 shared

Education

• PhD, Psychology

  University of Alabama at Birmingham