Racial and ethnic differences in experimental pain sensitivity: systematic review and meta-analysis

Effects of Savoring Meditation on Positive Emotions and Pain-Related Brain Function: A Mechanistic Randomized Controlled Trial in People With Rheumatoid Arthritis

Positive emotions are a promising target for intervention in chronic pain, but mixed findings across trials to date suggest that existing interventions may not be optimized to efficiently engage the target. The aim of the current pilot mechanistic randomized controlled trial was to test the effects of a positive emotion-enhancing intervention called Savoring Meditation on pain-related neural and behavioral targets in patients with rheumatoid arthritis. Participants included 44 patients with a physician-confirmed diagnosis of rheumatoid arthritis (n = 29 included in functional magnetic resonance imaging (fMRI) analyses), who were randomized to either Savoring Meditation or a Slow Breathing control. Both meditation interventions were brief (four 20-minute sessions). Self-report measures were collected pre-and post-intervention. An fMRI task was conducted at post-intervention, during which participants practiced the meditation technique on which they had been trained while exposed to non-painful and painful thermal stimuli. Savoring significantly reduced experimental pain intensity ratings relative to rest (P < .001). Savoring also increased cerebral blood flow in the ventromedial prefrontal cortex and increased connectivity between the ventromedial prefrontal cortex and caudate during noxious thermal stimulation relative to Slow Breathing (z = 2.3 voxelwise, false discovery rate cluster corrected P = .05). Participants in the Savoring condition also reported significantly increased positive emotions (ps < .05) and reduced anhedonic symptoms (P < .01) from pre- to post-intervention. These findings suggest that Savoring recruits reward-enhancing corticostriatal circuits in the face of pain, and future work should extend these findings to evaluate if these mechanisms of Savoring are associated with improved clinical pain outcomes in diverse patient populations. PERSPECTIVE: Savoring Meditation is a novel positive emotion-enhancing intervention designed for patients with chronic pain. The present findings provide preliminary evidence that Savoring Meditation is acutely analgesic, and engages neural and subjective emotional targets that are relevant to pain self-management. Future work should evaluate the clinical translation of these findings.

Social Determinants and Consequences of Pain: Towards Multilevel, Intersectional, and Life Course Perspectives

Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain remain rarely addressed in the context of pain prevention and management. In this review, we aim to: 1) examine the broad scope of social determinants and consequences of pain and their interactions across multiple levels of organization, and 2) provide a framework synthesizing existing concepts and potential areas for future work on social aspects of pain, drawing upon socioecological, intersectional, and life course approaches. Integrating interdisciplinary theory and evidence, we outline pathways through which multilevel social factors and pain may affect each other over time. We also provide a brief summary of intrapersonal aspects of pain which are thought to operate at the interface between individuals and the social context. Progressing from micro- to macro-level factors, we illustrate how social determinants of pain can directly or indirectly contribute to pain experiences, expression, risk, prognosis, and impact across populations. We consider: a) at the interpersonal level, the roles of social comparison, social relatedness, social support, social exclusion, empathy and interpersonal conflict; b) at the group or community level, the roles of intimacy groups, task groups, social categories, and loose associations; and c) at the societal level, the roles of political, economic, and cultural systems, as well as their policies and practices. We present examples of multilevel consequences of pain across these levels and discuss opportunities to reduce the burden and inequities of pain by expanding multilevel social approaches in pain research and practice. PERSPECTIVE: Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain are often unclearly defined, hindering their use in pain prevention, management, and research. We summarize the scope of social aspects of pain and provide a framework synthesizing existing concepts and potential areas for future work.

Trends in Patient Representation in Low Back Pain Pharmacological Randomized Clinical Trials, 2011 to 2020: A Systematic Review

Low back pain (LBP) significantly affects global health, with associated detrimental outcomes such as physical impairment, emotional distress, and exacerbated mental health symptoms. This study evaluated the representation of marginalized groups, including racialized, gender minority, pregnant/lactating, and elderly individuals in randomized controlled trials for pharmacological interventions treating LBP from 2011 to 2020. We searched Embase, MEDLINE, and CINAHL in December 2021, and 139 studies were eligible. Most trials (n = 113, 81%) reported participant sex; however, no study collected data on sexual and gender minorities, and the majority (n = 99, 71%) excluded pregnant/lactating individuals. Most trials (n = 105, 76%) reported no data on participant race or ethnicity. We limited within-country analyses of race and ethnicity to US-based trials because US-based trials were more likely to report race and/or ethnicity (48%) compared to non-US-based trials (8%). Black participants were the only racialized group whose composition was comparable to US Census estimates. About half (n = 73, 53%) of all trials had an upper age limit for eligibility (range: 40-85 years old) and 24% (n = 33) excluded adults aged >65 years. Our findings confirm that trials for pharmacological LBP interventions underreport demographic data, and the trials that include this data have unrepresentative samples. There is an urgent need for more inclusive and representative patient samples to ensure generalizability and equitable benefits. Standardizing demographic data reporting and integrating community-based participatory research methods can help foster inclusive research practices. This review was registered with prospective register of systematic reviews (PROSPERO), ID 296017. PERSPECTIVE: This systematic review investigates patient representation in pharmacological-based clinical trials for low back pain, LBP, the most prevalent pain condition worldwide. Improvements in reporting demographic data and recruiting diverse participant populations-across different racialized, gender and sexual minority, and age groups-will help clinical research generalizability and provide equitable benefits.

Do emergency medicine health care workers rate triage level of chest pain differently based upon appearance in simulated patients?

BACKGROUND AND IMPORTANCE

There seems to be evidence of gender and ethnic bias in the early management of acute coronary syndrome. However, whether these differences are related to less severe severity assessment or to less intensive management despite the same severity assessment has not yet been established.

OBJECTIVE

To show whether viewing an image with characters of different gender appearance or ethnic background changes the prioritization decision in the emergency triage area.

METHODS

The responders were offered a standardized clinical case in an emergency triage area. The associated image was randomized among eight standardized images of people presenting with chest pain and differing in gender and ethnic appearance (White, Black, North African and southeast Asian appearance).

OUTCOME MEASURES AND ANALYSIS

Each person was asked to respond to a single clinical case, in which the priority level [from 1 (requiring immediate treatment) to 5 (able to wait up to 2 h)] was assessed visually. Priority classes 1 and 2 for vital emergencies and classes 3-5 for nonvital emergencies were grouped together for analysis.

RESULTS

Among the 1563 respondents [mean age, 36 ± 10 years; 867 (55%) women], 777 (50%) were emergency physicians, 180 (11%) emergency medicine residents and 606 (39%) nurses. The priority levels for all responses were 1-5 : 180 (11%), 686 (44%), 539 (34%), 131 (9%) and 27 (2%). There was a higher reported priority in male compared to female [62% vs. 49%, difference 13% (95% confidence interval; CI 8-18%)]. Compared to White people, there was a lower reported priority for Black simulated patients [47% vs. 58%, difference -11% (95% CI -18% to -4%)] but not people of southeast Asian [55% vs. 58%, difference -3% (95% CI -10-5%)] and North African [61% vs. 58%, difference 3% (95% CI -4-10%)] appearance.

CONCLUSION

In this study, the visualization of simulated patients with different characteristics modified the prioritization decision. Compared to White patients, Black patients were less likely to receive emergency treatment. The same was true for women compared with men.

Music from Noise-Canceling Headphones Is Beneficial against Anxiety in Male Bladder Cancer Patients Undergoing Follow-Up Cystoscopy: A Prospective Randomized Trial

INTRODUCTION

Bladder cancer, with a greater incidence in males than in females, requires frequent cystoscopies. We aimed to evaluate the effect of music played through noise-canceling headphones on male bladder cancer patients during follow-up cystoscopy.

METHODS

A total of 160 male bladder cancer patients undergoing follow-up flexible cystoscopy were randomly divided into the noise-canceling headphones without music group and the noise-canceling headphones with music group (groups 1 and 2, respectively; n = 80 per group). The patients' clinical characteristics were examined, and objective and subjective measurements were compared before and after cystoscopy. The primary outcomes that were evaluated included the visual analog scale (VAS, 0-10) and the state-trait anxiety inventory (STAI, 20-80). Other outcomes, including vital signs and scores for assessing satisfaction and the willingness to repeat the procedure, were also examined.

RESULTS

The characteristics of the patients in groups 1 and 2, and their pre-cystoscopy status, did not differ significantly. Although post-cystoscopy vital signs for the objective parameters and VAS pain scores were similar between the groups, subjective parameters were not. When compared with group 1, post-cystoscopy STAI-state scores were significantly lower in group 2, whereas patients' satisfaction scores and the willingness to repeat the procedure were significantly higher in group 2 (p = 0.002, 0.001, and 0.001, respectively). Additionally, in group 2, STAI-state scores changed significantly after the procedure when compared with before the procedure (p = 0.002).

CONCLUSION

Providing music to male bladder cancer patients through noise-canceling headphones was found to reduce anxiety during cystoscopy and to improve patient satisfaction and willingness to undergo repeat cystoscopy.

Bystander Acknowledgment Mitigates the Psychological and Physiological Pain of Racial Discrimination for Black Young Adults: A Randomized Controlled Trial

Racism increases pain sensitization and contributes to racialized pain inequities; however research has not tested interventions targeting racism to reduce pain. In this study we examined whether White bystanders can act to mitigate racism's pain sensitizing effects. To simulate racial exclusion in the laboratory, Black young adults (age 18-30; N = 92) were randomly assigned to be included or excluded by White players in a ball-tossing game (Cyberball). For half of excluded participants, White bystanders acknowledged and apologized for the racial exclusion. Participants completed a cold pressor task to assess pain threshold, tolerance, and unpleasantness; and completed a survey assessing psychological needs (i.e., belongingness, self-esteem, meaningful existence, and self-control). Participants who experienced racial exclusion reported significantly more threatened psychological needs and increased laboratory pain sensitization (i.e., lower pain threshold and tolerance) than those who were included. However, when a White bystander acknowledged the racism, excluded participants reported higher levels of self-control, self-esteem, and decreased pain sensitization (pain threshold and tolerance) relative to excluded participants whose experience was not acknowledged. Our findings support that racism increased Black people's pain sensitivity and provide initial evidence for White bystander acknowledgment as a health intervention. PERSPECTIVE: Continual exposure to racism likely contributes to inequities in pain sensitization. We demonstrate that acute exposure to mild racism increases acute pain sensitization. Results suggest that a bystander acknowledging witnessed racism can buffer the acute sensitizing effects of racism on pain, pointing to the potential of interpersonal interventions targeting racism.

Serum Vitamin D and Chronic Musculoskeletal Pain: A Cross-Sectional Study of 349,221 Adults in the UK

Insufficient and deficient vitamin D may be associated with chronic musculoskeletal pain, but study findings are conflicting, and few account for important confounding factors. This cross-sectional study explored the association between serum vitamin D status and chronic musculoskeletal pain in various body sites, adjusting for a wide range and a number of potential confounding factors. Data collected at the baseline assessments of 349,221 UK Biobank participants between 2006 and 2010 were analyzed. Serum 25-hydroxyvitamin D was measured and categorized as <25.0 nmol/L (severe deficiency), 25.0 to 49.9 nmol/L (deficiency), 50.0 to 74.9 nmol/L (insufficiency), and ≥75.0 nmol/L (sufficiency). The outcome was self-reported chronic musculoskeletal pain at any site, neck/shoulder, back, hip, knee, or widespread pain that interfered with usual activities. Potential confounders were identified using directed acyclic graphs and included sociodemographic, lifestyle, psychological factors, and medical comorbidities. Simple models adjusted for age and sex showed significant associations between suboptimal vitamin D status and chronic pain across all sites (odds ratios [ORs] ranged 1.07-2.85). These associations were weakened or became insignificant after accounting for all confounding factors (ORs ≤ 1.01) for chronic regional musculoskeletal pain. Severe vitamin D deficiency remained a significant and positive association with chronic widespread pain after adjusting for all confounding factors (OR [95% confidence interval]: 1.26 [1.07, 1.49]). This study suggests that, while vitamin D status is not a key independent determinant of chronic regional musculoskeletal pain, severe vitamin D deficiency may be associated with chronic widespread pain. PERSPECTIVES: After accounting for various confounders, vitamin D deficiency was not associated with regional musculoskeletal pain. However, the relationship between chronic widespread pain severe vitamin D deficiency remained after confounder adjustment. Use of vitamin D supplements in individuals with chronic widespread pain and severe vitamin D deficiency warrants further exploration.

Exploring the association of gender role expectations of pain and measures of pain sensitization in people with knee osteoarthritis: A cross-sectional study

OBJECTIVES

First, we explored the association between Gender Role Expectations of Pain (GREP), and psychophysical measures of sensitization in people with knee osteoarthritis (OA). Second, we explored whether the association differed by level of GREP items (high vs low scores).

DESIGN

We conducted secondary analyses of a cohort study. Those who were (i) age of ≥40, English or French speaking, ii) diagnosed with knee OA using American College of Rheumatology criteria and iii) consulting with an orthopedic surgeon were included. GREP items pertaining to pain sensitivity and pain endurance of the typical man or woman were rated by males and females respectively. Psychophysical tests consisted of pressure pain thresholds (PPTs), Temporal Summation (TS), and Conditioned Pain Modulation (CPM). Multiple linear regression models for males and females were run with GREP scores (independent variables) and psychophysical tests (dependent variables). Next models stratified on the median split of GREP scores were run. Models were adjusted for age, BMI, pain catastrophizing, anxio-depressive symptoms, and radiographic severity.

RESULTS

280 participants (57% females; age (SD): 63.9 (9.6) and BMI (SD): 31.3 (8.40)) were included. GREP pain sensitivity scores in males were associated with CPM values (β: 95% CI: 0.09 (0.01 to 0.17)). Males with low GREP pain sensitivity or pain endurance had very small to small positive associations with PPT and CPM values.

CONCLUSION

This first exploration of gendered pain sensitivity and pain endurance by males and females has small and clinically unimportant associations with measures of pain sensitization requiring further validation.

The normative values of pain thresholds in healthy Taiwanese

OBJECTIVE

Quantitative sensory testing is widely used in clinical and research settings to assess the sensory functions of healthy subjects and patients. It is of importance to establish normative values in a healthy population to provide reference for studies involving patients. Given the absence of normative values for pain thresholds in Taiwan, the aim of this study was to report the normative values for future reference in the Taiwanese population and compare the differences between male and female participants.

METHODS

Healthy adults without any chronic or acute pain condition were recruited. The pain thresholds were assessed over the cephalic (supraorbital area and masseter muscle) and extracephalic (medio-volar forearm and thenar eminence) areas. The heat, cold, mechanical punctate, and pressure pain thresholds were measured with a standardized protocol. Comparisons between male and female participants were performed.

RESULTS

One hundred and thirty healthy participants (55 males: 30.4 ± 7.4 years; 75 females: 30.5 ± 8.1 years) finished the assessments. Male participants were less sensitive to mechanical stimuli, including pressure over masseter muscle (male vs. female: 178.5 ± 56.7 vs. 156.6 ± 58.4 kPa, p = .034) and punctate over medio-volar forearm (male vs. female: 116.4 ± 45.2 vs. 98.7 ± 65.4 g, p = .011), compared to female participants. However, female participants were less sensitive to cold stimuli, indicated by lower cold pain thresholds over the supraorbital area (male vs. female: 18.6 ± 8.4 vs. 13.6 ± 9.3°C, p = .004), compared to male participants. No significant differences were found between sexes in other pain threshold parameters.

CONCLUSIONS

We provided the normative values of healthy male and female adults in Taiwan. This information is crucial for comparison in future pain-related studies to identify potential hypoalgesia or hyperalgesia of tested subjects.

The effect of experimental emotion induction on experimental pain: a systematic review and meta-analysis

ABSTRACT

The idea that emotions can influence pain is generally recognized. However, a synthesis of the numerous individual experimental studies on this subject is lacking. The aim of the present systematic review and meta-analysis was to synthesize the existing evidence on the effect of experimental emotion induction on experimental pain in nonclinical adults. PsycInfo and PubMed were searched up until April 10, 2023, for studies assessing differences in self-reported pain between emotion induction groups and/or control groups or between conditions within group. Risk of bias was assessed for the individual studies. The literature search yielded 78 relevant records of 71 independent studies. When compared with control conditions, the pooled results revealed a statistically significant pain-attenuating effect of positive emotion induction (between-group: Hedges g = -0.48, 95% CI: -0.72; -0.25, K = 9; within-group: g = -0.24, 95% CI: -0.32; -0.15, K = 40), and a statistically significant pain-exacerbating effect of negative emotion induction in within-group analyses but not between-group analyses (between-group: g = -0.29, 95% CI: -0.66; 0.07, K = 10; within-group: g = 0.14, 95% CI: 0.06; 0.23, K = 39). Bayesian meta-analysis provided strong support for an effect of positive emotion induction but weak support for an effect of negative emotion induction. Taken together, the findings indicate a pain-attenuating effect of positive emotion induction, while the findings for negative emotion induction are less clear. The findings are discussed with reference to theoretical work emphasizing the role of motivational systems and distraction for pain. Limitations include considerable heterogeneity across studies limiting the generalizability of the findings.

The Impact of Sleep Disturbances on Endogenous Pain Modulation: A Systematic Review and Meta-Analysis

The bidirectional relationship between sleep and pain problems has been extensively demonstrated but despite all the accumulating evidence, their shared mechanisms are currently not fully understood. This review examined the association between sleep disturbances, defined as a broad array of sleep-related outcomes (eg, poor quality, short duration, insomnia), and endogenous pain modulation (EPM) in healthy and clinical populations. Our search yielded 6,151 references, and 37 studies met the eligibility criteria. Qualitative results showed mixed findings regarding the association between sleep disturbances and temporal summation of pain (TSP) and conditioned pain modulation (CPM), with poor sleep more commonly associated with decreased pain inhibition in both populations. Quantitative results indicated that such associations were not statistically significant, neither in healthy populations when EPM outcomes were assessed for changes pre-/post-sleep intervention (TSP: .31 [95%CI: -.30 to .92]; P = .321; CPM: .40 [95%CI: -.06 to .85] P = .088) nor in clinical populations when such association was assessed via correlation (TSP: -.00 [95%CI: -.22 to .21] P = .970; CPM: .12 [95%CI: -.05 to .29]; P = .181). For studies that reported results by sex, meta-analysis showed that experimental sleep disturbances impaired pain inhibition in females (1.43 [95%CI: .98-1.88]; P < .001) but not in males (-.30 [95%CI: -2.69 to 1.60]; P = .760). Only one study investigating the association between sleep disturbances and offset analgesia was identified, while no studies assessing spatial summation of pain were found. Overall, this review provides a comprehensive overview of the association between sleep disturbances and EPM function, emphasizing the need for further investigation to clarify specific mechanisms and phenotypic subtypes. PERSPECTIVE: This review shines a light on the association between sleep disturbances and endogenous pain modulation function. Qualitatively, we found a frequent association between reduced sleep quality and impaired pain inhibition. However, quantitatively such an association was not corroborated. Sex-specific effects were observed, with females presenting sleep-related impaired pain inhibition but not males.

Assessing pain in persons with opioid use disorder: Approaches, techniques and special considerations

Pain and opioid use disorder (OUD) are inextricably linked, as the former can be a risk factor for the development of the latter, and over a third of persons with OUD suffer concomitant chronic pain. Assessing pain among people with OUD is challenging, because ongoing opioid use brings changes in pain responses and most pain assessment tools have not been validated for this population. In this narrative review, we discuss the fundamentals of pain assessment for populations with OUD. First, we describe the biological, psychological and social aspects of the pain experience among people with OUD, as well as how opioid-related phenomena may contribute to the pain experience in this population. We then review methods to assess pain, including (1) traditional self-reported methods, such visual analogue scales and structured questionnaires; (2) behavioural observations and physiological indicators; (3) and laboratory-based approaches, such as quantitative sensory testing. These methods are considered from a perspective that encompasses both pain and OUD. Finally, we discuss strategies for improving pain assessment in persons with OUD and implications for future research, including educational strategies for multidisciplinary teams. We highlight the substantial gaps that persist in this literature, particularly regarding the applicability of current pain assessment methods to persons with OUD, as well as the generalizability of the existing results from adjacent populations on chronic opioid therapy but without OUD. As research linking pain and OUD evolves, considering the needs of diverse populations with complex psychosocial backgrounds, clinicians will be better equipped to reduce these gaps.

Disparities in access but not outcomes: Medicaid versus non-Medicaid patients in multidisciplinary chronic pain rehabilitation

Purpose: There are known disparities in chronic pain severity, treatment, and opioid-related risks amongst individuals from lower socioeconomic status, including Medicaid beneficiaries, but little is known about whether Medicaid beneficiaries benefit in a similar way from multidisciplinary chronic pain rehabilitation. This study investigated differences in clinical outcomes between Medicaid and non-Medicaid beneficiaries who completed a 3-week multidisciplinary chronic pain rehabilitation program.Methods: Participants (N = 131) completed a broad range of clinical measures pre- and post-treatment including pain severity, pain interference, depression, anxiety, objective physical functioning, and opioid misuse risk. Patients with Medicaid were compared with non-Medicaid patients in terms of baseline characteristics and rate of change, utilizing two-factor repeated measures analyses of variance.Results: There were baseline characteristic differences, with Medicaid beneficiaries being more likely to be African American, have higher rates of pain, worse physical functioning, and lower rates of opioid use. Despite baseline differences, both groups demonstrated significantly improved outcomes across all measures (p<.001) and no significant difference in rate of improvement.Conclusions: Results suggest that pain rehabilitation is as effective for Medicaid recipients as non-Medicaid recipients. Patients with Medicaid are particularly vulnerable to disparities in treatment, so efforts to expand access to multidisciplinary pain treatments are warranted.

Biobehavioral Predictors of Pain Intensity, Pain Interference, and Chronic Pain Episodes: A Prospective Cohort Study of African-American Adults

Racial disparities in pain experiences are well-established, with African-American (AA) adults reporting higher rates of daily pain, increased pain severity, and greater pain-related interference compared to non-Hispanic Whites. However, the biobehavioral factors that predict the transition to chronic pain among AA adults are not well understood. This prospective cohort study provided a unique opportunity to evaluate predictors of chronic pain onset among 130 AA adults (81 women), ages 18 to 44, who did not report chronic pain at their baseline assessment and subsequently completed follow-up assessments at 6- and 12-months. Outcome measures included pain intensity, pain-related interference, and chronic pain status. Comprehensive assessments of sociodemographic and biobehavioral factors were used to evaluate demographics, socioeconomic status, stress exposure, psychosocial factors, prolonged hypothalamic-pituitary-adrenal secretion, and quantitative sensory testing responses. At baseline, 30 adults (23.1%) reported a history of prior chronic pain. Over the 12-month follow-up period, 13 adults (10.0%) developed a new chronic pain episode, and 18 adults (13.8%) developed a recurrent chronic pain episode. Whereas socioeconomic status measures (ie, annual income, education) predicted changes in pain intensity over the follow-up period, quantitative sensory testing measures (ie, pain threshold, temporal summation of pain) predicted changes in pain interference. A history of chronic pain and higher depressive symptoms at baseline independently predicted the onset of a new chronic pain episode. The present findings highlight distinct subsets of biobehavioral factors that are differentially associated with trajectories of pain intensity, pain-related interference, and onset of chronic pain episodes in AA adults. PERSPECTIVE: This prospective study sought to advance understanding of biobehavioral factors that predicted pain outcomes over a 12-month follow-up period among AA adults without chronic pain at their initial assessment. Findings revealed distinct subsets of factors that were differentially associated with pain intensity, pain-related interference, and onset of chronic pain episodes.

A secondary analysis: the impact of pre-existing chronic pain among patients with cancer presenting to the emergency department with acute pain

PURPOSE

Patients with cancer may experience pain from cancer itself or its treatment. Additionally, chronic pain (CP) predating a patient's cancer diagnosis may make the etiology of pain less clear and the management of pain more complex. In this brief report, we investigated differences in biopsychosocial characteristics, pain severity, and opioid consumption, comparing groups of cancer patients with and without a history of CP who presented to the emergency department (ED) with a complaint of cancer-related pain.

METHODS

This secondary analysis of a prospective cohort study included patients with cancer who presented to the ED with a complaint of pain (≥ 4/10). Sociodemographic, clinical, psychological, and pain characteristics were assessed in the ED and subsequent hospitalization. Mann-Whitney U-, T-, and Chi-square tests were used to compare differences between patients with and without pre-existing CP before cancer.

RESULTS

Patients with pre-existing CP had lower income (p = 0.21) and less formal education (p = 0.25) and were more likely to have a diagnosis of depression or substance use disorder (p < 0.01). Patients with pre-existing CP reported significantly greater pain severity in the ED and during hospitalization compared to those without pre-existing CP (p < 0.05), despite receiving greater amounts of opioid analgesics (p = 0.036).

CONCLUSION

Identifying a history of pre-existing CP during intake may help identify patients with cancer with difficult to manage pain, who may particularly benefit from multimodal interventions and supportive care. In addition, referral of these patients for the management of co-occurring pain disorders may help decrease the usage of the ED for undertreated pain.

Association between earthquakes and perinatal outcomes: A systematic review and meta-analysis

BACKGROUND

Evidence for the association between earthquakes and adverse perinatal outcomes is limited.

OBJECTIVES

To evaluate the association between earthquakes and perinatal outcomes including preterm birth and low birth weight.

SEARCH STRATEGY

We searched studies using MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, World Health Organization International Clinical Trials Platform Search Portal, and ClinicalTrials.gov on February 9, 2023.

SELECTION CRITERIA

We included before-and-after studies that evaluated the associations between earthquakes and perinatal outcomes in women living in affected areas.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data. We calculated the pooled odds ratio (OR) with the random-effects model. We analyzed outcomes in subgroups of Asians and others. We evaluated the certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation system.

MAIN RESULTS

We included 2 607 405 women in 13 studies. Earthquakes may not increase preterm birth (nine studies, 1 761 760 participants: OR 1.10, 95% confidence interval [CI] 0.98-1.24, low certainty of evidence) or low birth weight (seven studies, 1 753 891 participants: OR 1.10, 95% CI 0.94-1.28, low certainty of evidence). Subgroup analyses showed that earthquakes may be associated with an increase of preterm birth among populations in Asia (OR 1.44, 95% CI 1.07-1.95), but this was not evident in others (OR 0.93, 95% CI 0.83-1.05).

CONCLUSIONS

Perinatal outcomes might not change after earthquakes. Further research on the association between earthquakes and perinatal outcomes, combined with an assessment of the characteristics of the region, is needed.

Secondary analysis: heat and self-report pain sensitivity associate with biological sex and racialized sociocultural group but may not be mediated by anxiety or pain catastrophizing

Introduction

Previous studies have demonstrated associations between sex and racialized group on pain sensitivity and tolerance. We analyzed the association of sex and racialized group on heat pain sensitivity, sensibility to painful suprathreshold mechanical pain (STMP), and pain sensitivity questionnaire (PSQ). We hypothesized that anxiety and pain catastrophizing reported by racialized minority groups and women would mediate enhanced pain sensitivity. Our secondary aim was to evaluate validity of the PSQ in a diverse population.

Methods

Using quantitative sensory testing for painful heat, STMP (forces: 64, 128, 256, and 512 mN), and PSQ, we evaluated pain sensitivity in 134 healthy participants [34 (18 women) Asian, 25 (13 women) Black, and 75 (41 women) White]. We used general linear and linear mixed models to analyze outcomes. We assessed mediation of state and trait anxiety and pain catastrophizing on pain sensitivity.

Results

Racialized minority status was associated with greater heat pain sensitivity (F = 7.63; P = 0.00074) and PSQ scores (F = 15.45; P = 9.84 × 10-7) but not associated with STMP (F = 1.50; P = 0.23). Female sex was associated with greater heat pain sensitivity (F = 4.9; P = 0.029) and lower PSQ (F = 9.50; P = 0.0025) but not associated with STMP (F = 0.0018; P = 0.97). Neither anxiety nor pain catastrophizing mediated associations between sex or racialized group with heat pain threshold or PSQ. Differential experience of individual items (F = 19.87; P = 3.28 × 10-8) limited PSQ face validity in racialized minorities.

Conclusion

Consistent with previous research, sensitivity to painful heat was associated with racialized minority status and female sex. By contrast, there was no significant effect of racialized minority status or female sex on STMP. Some PSQ items are inapplicable to participants from racialized minority groups.

Greater socioenvironmental risk factors and higher chronic pain stage are associated with thinner bilateral temporal lobes

INTRODUCTION

Previous research indicates ethnic/race group differences in pain and neurodegenerative diseases. Accounting for socioenvironmental factors reduces ethnic/race group differences in clinical and experimental pain. In the current study sample, we previously reported that in individuals with knee pain, ethnic/race group differences were observed in bilateral temporal lobe thickness, areas of the brain associated with risk for Alzheimer's disease, and related dementias. The purpose of the study was to determine if socioenvironmental factors reduce or account for previously observed ethnic/race group differences and explore if a combined effect of socioenvironmental risk and chronic pain severity on temporal lobe cortices is evident.

METHODS

Consistent with the prior study, the sample was comprised of 147 adults (95 women, 52 men), 45-85 years of age, who self-identified as non-Hispanic Black (n = 72) and non-Hispanic White (n = 75), with knee pain with/at risk for osteoarthritis. Measures included demographics, health history, pain questionnaires, cognitive screening, body mass index, individual- and community-level socioenvironmental factors (education, income, household size, marital and insurance status, and area deprivation index), and brain imaging. We computed a summative socioenvironmental risk index.

RESULTS

Regression analyses showed that with the inclusion of socioenvironmental factors, the model was significant (p < .001), and sociodemographic (ethnic/race) group differences were not significant (p = .118). Additionally, findings revealed an additive stress load pattern indicating thinner temporal lobe cortices with greater socioenvironmental risk and chronic pain severity (p = .048).

IMPLICATIONS

Although individual socioenvironmental factors were not independent predictors, when collectively combined in models, ethnic/race group differences in bilateral temporal lobe structures were not replicated. Further, combined socioenvironmental risk factors and higher chronic pain severity were associated with thinner bilateral temporal lobes.

Adversity type and timing predict temporal summation of pain in African-American adults

African Americans are disproportionately exposed to adversity across the lifespan, which includes both stressful and traumatic events. Adversity, in turn, is associated with alterations in pain responsiveness. Racial differences in pain responsiveness among healthy adults are well established. However, the extent to which adversity type and timing are associated with alterations in pain responsiveness among healthy African-American adults is not well understood. The present study included 160 healthy African-American adults (98 women), ages 18 to 45. Outcome measures included pain tolerance and temporal summation of pain to evoked thermal pain. Composite scores were created for early-life adversity (childhood trauma, family adversity) and recent adversity (perceived stress, chronic stress burden). A measure of lifetime racial discrimination was also included. Higher levels of recent adversity were associated with higher temporal summation of pain, controlling for gender, age, and education. Neither early-life adversity nor lifetime racial discrimination were associated with temporal summation of pain. The present findings suggest that heightened temporal summation of pain among healthy African-American adults is associated with exposure to recent adversity events. Improved understanding of how recent adversity contributes to heightened temporal summation of pain in African Americans could help to mitigate racial disparities in pain experiences by identifying at-risk individuals who could benefit from early interventions.

Sex Differences in Pain and Quantitative Sensory Testing in Patients With Rheumatoid Arthritis

OBJECTIVE

Women with rheumatoid arthritis (RA) have higher pain and worse functional outcomes compared to men, even when treated with similar medications. The objective of this study was to identify sex differences in pain intensity, pain interference, and quantitative sensory tests (QST), which are independent of inflammation, in patients with RA.

METHODS

This study is a post hoc analysis of participants in the Central Pain in Rheumatoid Arthritis cohort. Pain intensity was assessed using a 0-10 numeric rating scale. Pain interference was measured using a Patient-Reported Outcomes Measurement Information System computerized adaptive test. QST included pressure pain detection thresholds, temporal summation, and conditioned pain modulation. Women and men were compared using multiple linear regression, adjusted for age, education, race, research site, depression, obesity, RA disease duration, swollen joint count, and C-reactive protein.

RESULTS

Mean ± SD pain intensity was 5.32 ± 2.29 among women with RA, compared to 4.60 ± 2.23 among men with RA (adjusted difference 0.83 [95% confidence interval (95% CI) 0.14, 1.53]). Women with RA had lower pressure pain detection thresholds at the trapezius (adjusted difference -1.22 [95% CI -1.73, -0.72]), wrist (adjusted difference -0.57 [95% CI -1.07, -0.06]), and knee (adjusted difference -1.10 [95% CI -2.00, -0.21]). No statistically significant differences in pain interference, temporal summation, and conditioned pain modulation were observed.

CONCLUSION

Women reported higher pain intensity and lower pressure pain detection thresholds (higher pain sensitivity) than men. However, pain interference, temporal summation, and conditioned pain modulation did not differ between men and women.

Risk Factors Analysis of Phantom Limb Pain in Amputees with Malignant Tumors

Purpose

Postamputation neuropathic pain is a common disease in patients with malignant tumor amputation, seriously affecting amputees' quality of life and mental health. The objective of this study was to identify independent risk factors for phantom limb pain in patients with tumor amputation and to construct a risk prediction model.

Methods

Patients who underwent amputation due to malignant tumors from 2013 to 2023 were retrospectively analyzed and divided into phantom limb pain group and non-phantom limb pain group. To determine which preoperative factors would affect the occurrence of phantom limb pain, we searched for candidate factors by univariate analysis and used multivariate logistic regression analysis to identify independent factors and construct a predictive model. The receiver operating characteristic curve (ROC) was drawn to further evaluate the accuracy of the prediction model in evaluating the phantom limb pain after amputation of bone and soft tissue tumors.

Results

Multivariate analysis showed that age (OR, 1.054; 95% CI, 1.027 to 1.080), preoperative pain (OR, 5.773; 95% CI, 2.362 to 14.104), number of surgeries (OR, 3.425; 95% CI, 1.505 to 7.795), amputation site (OR, 5.848; 95% CI, 1.837 to 18.620), amputation level (OR, 8.031; 95% CI, 2.491 to 25.888) were independent risk factors for phantom limb pain for bone and soft tissue tumors. The the area under the curve (AUC) of this model was 0.834.

Conclusion

Risk factors for postoperative phantom limb pain were the site of amputation, proximal amputation, preoperative pain, multiple amputations, and older age. These factors will help surgeons to individualize and stratify phantom limb pain and help patients with risk counseling. In particular, an informed clinical decision targeting those modifiable factors can be considered when needed.

Clinicohistological Characteristics of Patients with Oral Lichenoid Mucositis: A Retrospective Study for Dental Hospital Records

Oral lichenoid mucositis (OLM) of the oral mucosa is a histological diagnosis mainly characterised by a band of inflammatory infiltrate in lamina propria and basal cell degeneration. These features describe oral lichen planus or oral lichenoid reaction. However, it could be seen in oral dysplasia. The study aimed to assess the demographics and clinicohistological characteristics of patients with OLM and their relevance to dysplastic changes in the oral mucosa. This was a cross-sectional and retrospective study of archived and electronic records of individuals with histological confirmation of OLM at King Saud University Medical City, Saudi Arabia. The descriptive and correlation assessments were used to describe the demographics and clinicohistological characteristics and their associations, respectively [p < 0.05]. The analysis included 140 records of patients with histological confirmation of OLM with a mean age of 47 (±13), and 57% (n = 81) were females. Notably, 40% of patients had at least one medical condition, mainly diabetes mellitus, 74% were asymptomatic, and 52% had lesions in the buccal mucosa. Dysplasia was seen in 18 (12%) of the 140 reviewed records. Regarding the associations between study variables, dysplastic changes were associated with the male gender [p = 0.024] and were of no significance with increased age [p = 0.594]. Moreover, having oral symptoms was associated with older age [p < 0.001], medical history of diabetes [p = 0.0132] and hypertension [p < 0.001]. The present study findings could help indicate the individuals with histologically confirmed OLM who suffer the most from the clinical disease and have an increased risk of dysplastic changes. Therefore, symptomatic management and long-term follow-up can be planned accordingly.

Effects of Savoring Meditation on Positive Emotions and Pain-Related Brain Function: A Mechanistic Randomized Controlled Trial in People With Rheumatoid Arthritis

Positive emotions are a promising target for intervention in chronic pain, but mixed findings across trials to date suggest that existing interventions may not be optimized to efficiently engage the target. The aim of the current mechanistic randomized controlled trial was to test the effects of a single skill positive emotion-enhancing intervention called Savoring Meditation on pain-related neural and behavioral targets in patients with rheumatoid arthritis (RA). Participants included 44 patients with a physician-confirmed diagnosis of RA (n=29 included in fMRI analyses), who were randomized to either Savoring Meditation or a Slow Breathing control. Both meditation interventions were brief (four 20-minute sessions). Self-report measures were collected pre- and post-intervention. An fMRI task was conducted at post-intervention, during which participants practiced the meditation technique on which they had been trained while exposed to non-painful and painful thermal stimuli. Relative to Slow Breathing, Savoring significantly reduced experimental pain intensity ratings relative to rest (p<.001), increased cerebral blood flow in the ventromedial prefrontal cortex (vmPFC) and increased connectivity between the vmPFC and caudate during noxious thermal stimulation (z=2.3 voxelwise, FDR cluster corrected p=0.05). Participants in the Savoring condition also reported significantly increased positive emotions (ps<.05) and reduced anhedonic symptoms (p<.01) from pre- to post-intervention. These findings suggest that that Savoring recruits reward-enhancing corticostriatal circuits in the face of pain, and future work should extend these findings to evaluate if these mechanisms of Savoring are associated with improved clinical pain outcomes in diverse patient populations.

Cultural Framing and the Impact On Acute Pain and Pain Services

PURPOSE OF REVIEW

Optimal treatment requires a thorough understanding of all factors contributing to pain in the individual patient. In this review, we investigate the influence of cultural frameworks on pain experience and management.

RECENT FINDINGS

The loosely defined concept of culture in pain management integrates a predisposing set of diverse biological, psychological and social characteristics shared within a group. Cultural and ethnic background strongly influence the perception, manifestation, and management of pain. In addition, cultural, racial and ethnic differences continue to play a major role in the disparate treatment of acute pain. A holistic and culturally sensitive approach is likely to improve pain management outcomes, will better cover the needs of diverse patient populations and help reduce stigma and health disparities. Mainstays include awareness, self-awareness, appropriate communication, and training.

Race-based reporting and participation of Black individuals in registered pain clinical trials, United States, 2000 to 2019

ABSTRACT

There are numerous, well-established racial disparities in the management of pain. The degree to which these are evident at the stage of conducting clinical trials is unknown. To address this knowledge gap, we examined race-based reporting, participation of Black individuals, and the factors associated with reporting and participation in pain clinical trials in the United States. Data were extracted from Clinicaltrials.gov and published articles. One thousand two hundred trials met our inclusion criteria; 482 (40.2%) reported participant race. More recent, publicly funded, and larger trials were more likely to report race. Of 82,468 participants included in pain clinical trials that reported race, 15,101 were Black individuals (18.3%). Participation of Black individuals was significantly associated with pain type (ß = +27% in cardiovascular disease pain compared with acute pain, P < 0.05), study population (ß = +33% and +7% in pain in minoritized populations and women, respectively, compared with general population, P < 0.05), pain intervention (ß = +7.5% for trials of opioid interventions compared with nonopioid interventions, P < 0.05), and a diverse team of investigators (ß = +8.0% for studies incorporating a visible non-White investigator compared with those that did not, P < 0.05). Our results indicate that representation of Black participants in pain clinical trials generally aligns with national demographics in the United States. Increased representation corresponds with health conditions more prevalent among Black individuals (eg, cardiovascular disease) and with a diverse study team composition. Despite these encouraging results, less than half of pain trials reported race, which introduces potential publication bias and limits external validity.

Racial Differences in Head Pain and Other Pain-Related Outcomes After Mild Traumatic Brain Injury

Recent research suggests that mild traumatic brain injury (TBI) may exert deleterious effects on endogenous pain modulatory function, potentially underlying the elevated risk for persistent headaches following injury. Accumulating research also shows race differences in clinical and experimental pain, with African Americans (AA) generally reporting more severe pain, worse pain modulation, and greater pain sensitivity compared with Caucasians. However, race differences in pain-related outcomes following mild TBI have rarely been studied. The purpose of this study was to explore race differences in endogenous pain modulation, pain sensitivity, headache pain, and psychological factors among AA and Caucasian individuals with mild TBI in the first month following injury compared with healthy controls and across time. Patients with mild TBI were recruited from local emergency department trauma centers. Sixty-three participants with mild TBI (AAs: n = 23, Caucasians: n = 40) enrolled in this study and completed study sessions at 1-2 weeks and 1-month post-injury. Forty-one mild-TBI-free control participants (AAs: n = 11, Caucasians: n = 30), matched on age and sex, completed one study session. Assessments included a Headache Survey, Pain Catastrophizing Scale, Center for Epidemiological Studies-Depression Scale (CES-D), and quantitative sensory testing (QST) to measure endogenous pain modulatory function. QST included conditioned pain modulation (CPM) to measure endogenous pain inhibitory function and temporal summation (TS) of pain and pressure pain thresholds (PPTs) of the head to measure pain sensitization and sensitivity. Two-way analysis of variance (ANOVA) was used to determine whether the outcome measures differed as a function of race, mild TBI, and time. Mediation analysis was used to explore potential mediators for the race differences in headache pain intensity. The results showed that AA participants with mild TBI reported significantly greater headache pain and pain catastrophizing and exhibited higher pain sensitivity and worse pain modulation on QST compared with Caucasian participants with mild TBI. These same race differences were not observed among the healthy TBI-free control sample. The mediation analyses showed complete mediation for the relation between race and headache pain intensity by pain catastrophizing at 1-2 weeks and 1-month post-injury. Overall, the results of this study suggest that AAs compared with Caucasians are characterized by psychological and pain modulatory profiles following mild TBI that could increase the risk for the development of intense and persistent headaches following injury.

Investigating the association factors of acute postpartum pain: a cohort study

BACKGROUND

Labor pain intensity is known to predict persistent postpartum pain, whereas acute postpartum pain may interfere with maternal postpartum physical, mental, and emotional well-being. Nevertheless, there is little research studying the association between labor pain intensity and acute postpartum pain. This study investigated the associations between labor pain intensity and psychological factors with acute postpartum pain.

METHODS

We included women with American Society of Anesthesiologists (ASA) physical status II, having ≥ 36 gestational weeks and a singleton pregnancy. We investigated the association between labor pain intensity (primary exposure) and high acute postpartum pain at 0 to 24 h after delivery (Numeric Rating Scale (NRS) ≥ 3 of 10; primary outcome). Pre-delivery questionnaires including Angle Labor Pain Questionnaire (A-LPQ), Pain Catastrophizing Scale (PCS), Fear Avoidance Components Scale (FACS) and State Trait Anxiety Inventory (STAI) were administered. Demographic, pain, obstetric and neonatal characteristics were also collected accordingly.

RESULTS

Of the 880 women studied, 121 (13.8%) had high acute postpartum pain at 0 to 24 h after delivery. A-LPQ total, PCS, FACS and STAI scores were not significantly associated with acute postpartum pain. Greater A-LPQ subscale on birthing pain (adjusted odds ratio (aOR) 1.03, 95% CI 1.01-1.05, p = 0.0008), increased blood loss during delivery (for every 10ml change; aOR 1.01, 95% CI 1.00-1.03, p = 0.0148), presence of shoulder dystocia (aOR 10.06, 95% CI 2.28-44.36, p = 0.0023), and use of pethidine for labor analgesia (aOR 1.74, 95% CI 1.07-2.84, p = 0.0271) were independently associated with high acute postpartum pain. "Sometimes" having nausea during menstruation before current pregnancy (aOR 0.34, 95% CI 0.16-0.72, p = 0.0045) was found to be independently associated with reduced risk of high acute postpartum pain.

CONCLUSIONS

Pre-delivery pain factor together with obstetric complications (shoulder dystocia, blood loss during delivery) were independently associated with high acute postpartum pain.

TRIAL REGISTRATION

This study was registered on clinicaltrials.gov registry (NCT03167905) on 30/05/2017.

Molecular Mechanisms and Pathophysiological Pathways of High-Fat Diets and Caloric Restriction Dietary Patterns on Pain

Pain perception provides evolutionary advantages by enhancing the probability of survival, but chronic pain continues to be a significant global health concern in modern society. Various factors are associated with pain alteration. Accumulating evidence has revealed that obesity correlates with enhanced pain perception, especially in chronic pain individuals. Existing dietary patterns related to obesity are primarily high-fat diets (HFD) and calorie restriction (CR) diets, which induce or alleviate obesity separately. HFD has been shown to enhance nociception while CR tends to alleviate pain when measuring pain outcomes. Herein, this review mainly summarizes the current knowledge of the effects of HFD and CR on pain responses and underlying molecular mechanisms of the immunological factors, metabolic regulation, inflammatory processes, Schwann cell (SC) autophagy, gut microbiome, and other pathophysiological signaling pathways involved. This review would help to provide insights on potential nonpharmacological strategies of dietary patterns in relieving pain.

A historical review of pain disparities research: Advancing toward health equity and empowerment

BACKGROUND AND PURPOSE

This theory-guided review draws on 30 years of published data to examine and interrogate the current and future state of pain disparities research.

METHODS

Using the Hierarchy of Health Disparity Research framework, we synthesize and present an overview of "three generations" of pain disparities scholarship, while proposing directions for adopting a "fourth generation" that redefines, explains, and theorizes future pain disparities research in a diverse society.

DISCUSSION

Prior research has focused on describing the scope of disparities, and throughout the historical context of human existence, racialized groups have been subjected to inadequate pain care. It is imperative that research not only illuminates existing problems but also provides solutions that can be implemented and sustained across varying social milieus.

CONCLUSION

We must invest in new theoretical models that expand on current perspectives and ideals that position all individuals at the forefront of justice and equity in their health.

Sex differences in pain expressed by patients across diverse disease states: individual patient data meta-analysis of 33,957 participants in 10 randomized controlled trials

ABSTRACT

The experience of pain is determined by many factors and has a significant impact on quality of life. This study aimed to determine sex differences in pain prevalence and intensity reported by participants with diverse disease states in several large international clinical trials. Individual participant data meta-analysis was conducted using EuroQol-5 Dimension (EQ-5D) questionnaire pain data from randomised controlled trials published between January 2000 and January 2020 and undertaken by investigators at the George Institute for Global Health. Proportional odds logistic regression models, comparing pain scores between females and males and fitted with adjustments for age and randomized treatment, were pooled in a random-effects meta-analysis. In 10 trials involving 33,957 participants (38% females) with EQ-5D pain score data, the mean age ranged between 50 and 74. Pain was reported more frequently by females than males (47% vs 37%; P < 0.001). Females also reported greater levels of pain than males (adjusted odds ratio 1.41, 95% CI 1.24-1.61; P < 0.001). In stratified analyses, there were differences in pain by disease group (P for heterogeneity <0.001), but not by age group or region of recruitment. Females were more likely to report pain, and at a higher level, compared with males across diverse diseases, all ages, and geographical regions. This study reinforces the importance of reporting sex-disaggregated analysis to identify similarities and differences between females and males that reflect variable biology and may affect disease profiles and have implications for management.

Metformin attenuates symptoms of osteoarthritis: role of genetic diversity of Bcl2 and CXCL16 in OA

OBJECTIVE

This study aimed to evaluate the effectiveness of metformin versus placebo in overweight patients with knee osteoarthritis (OA). In addition, to assess the effects of inflammatory mediators and apoptotic proteins in the pathogenesis of OA, the genetic polymorphisms of two genes, one related to apoptosis (rs2279115 of Bcl-2) and the other related to inflammation (rs2277680 of CXCL-16), were investigated.

METHODS

In this double-blind placebo-controlled clinical trial, patients were randomly divided to two groups, one group receiving metformin (n = 44) and the other one receiving an identical inert placebo (n = 44) for 4 consecutive months (starting dose 0.5 g/day for the first week, increase to 1 g/day for the second week, and further increase to 1.5 g/day for the remaining period). Another group of healthy individuals (n = 92) with no history and diagnosis of OA were included in this study in order to evaluate the role of genetics in OA. The outcome of treatment regimen was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. The frequency of variants of rs2277680 (A181V) and rs2279115 (938C>A) were determined in extracted DNAs using PCR-RFLP method.

RESULTS

Our results indicated an increase in scores of pain (P ≤ 0.0001), activity of daily living (ADL) (P ≤ 0.0001), sport and recreation (Sport/Rec) (P ≤ 0.0001), and quality of life (QOL) (P = 0.003) and total scores of the KOOS questionnaire in the metformin group compared to the placebo group. Susceptibility to OA was associated with age, gender, family history, CC genotype of 938C>A (Pa = 0.001; OR = 5.2; 95% CI = 2.0-13.7), and GG+GA genotypes of A181V (Pa = 0.04; OR = 2.1; 95% CI = 1.1-10.5). The C allele of 938C>A (Pa = 0.04; OR = 2.2; 95% CI = 1.1-9.8) and G allele of A181V (Pa = 0.02; OR = 2.2; 95% CI = 1.1-4.8) were also associated with OA.

CONCLUSION

Our findings support the possible beneficial effects of metformin on improving pain, ADL, Sport/Rec, and QOL in OA patients. Our findings support the association between the CC genotype of Bcl-2 and GG+GA genotypes of CXCL-16 and OA.

How Pain-Related Facial Expressions Are Evaluated in Relation to Gender, Race, and Emotion

Inequities in pain assessment are well-documented; however, the psychological mechanisms underlying such biases are poorly understood. We investigated potential perceptual biases in the judgments of faces displaying pain-related movements. Across five online studies, 956 adult participants viewed images of computer-generated faces (“targets”) that varied in features related to race (Black and White) and gender (women and men). Target identity was manipulated across participants, and each target had equivalent facial movements that displayed varying intensities of movement in facial action-units related to pain (Studies 1–4) or pain and emotion (Study 5). On each trial, participants provided categorical judgments as to whether a target was in pain (Studies 1–4) or which expression the target displayed (Study 5) and then rated the perceived intensity of the expression. Meta-analyses of Studies 1–4 revealed that movement intensity was positively associated with both categorizing a trial as painful and perceived pain intensity. Target race and gender did not consistently affect pain-related judgments, contrary to well-documented clinical inequities. In Study 5, in which pain was equally likely relative to other emotions, pain was the least frequently selected emotion (5%). Our results suggest that perceivers can utilize facial movements to evaluate pain in other individuals, but perceiving pain may depend on contextual factors. Furthermore, assessments of computer-generated, pain-related facial movements online do not replicate sociocultural biases observed in the clinic. These findings provide a foundation for future studies comparing CGI and real images of pain and emphasize the need for further work on the relationship between pain and emotion.

Elucidating factors contributing to disparities in pain-related experiences among adults with or at risk for knee osteoarthritis

Background and purpose

We and others have reported ethnic/race group differences in clinical pain, physical function, and experimental pain sensitivity. However, recent research indicates that with consideration for socioenvironmental factors, ethnicity/race differences become less or non-significant. Understanding of factors contributing to pain inequities are needed. Guided by the NIA and NIMHD Health Disparities Research Frameworks, we evaluate the contributions of environmental and behavioral factors on previously reported ethnic/race group differences in: (1) clinical pain, (2) physical function, and (3) experimental pain in individuals with knee pain.

Methods

Baseline data from Understanding of Pain and Limitations in Osteoarthritis Disease (UPLOAD) and UPLOAD-2 studies were analyzed. Participants were adults 45 to 85 years old who self-reported as non-Hispanic white (NHW) or black (NHB) with knee pain. A health assessment and quantitative sensory testing were completed. Sociodemographics, environmental, health, clinical and experimental pain, and physical functioning measures were included in nested regressions.

Results

Pooled data from 468 individuals, 57 ± 8 years of age, 63% women, and 53% NHB adults. As NHB adults were younger and reported greater socioenvironmental risk than the NHW adults, the term sociodemographic groups is used. With inclusion of recognized environmental and behavioral variables, sociodemographic groups remained a significant predictor accounting for <5% of the variance in clinical pain and physical function and <10% of variance in experimental pain.

Conclusion

The incorporation of environmental and behavioral factors reduced relationships between sociodemographic groups and pain-related outcomes. Pain sites, BMI, and income were significant predictors across multiple models. The current study adds to a body of research on the complex array of factors contributing to disparities in pain-related outcomes.

Acupoints sensitization in people with and without chronic low back pain:A matched-sample cross-sectional study

BACKGROUND

Acupoints are considered a dynamic functional area, which can reflect the internal condition of the body. In pathological states, disease-related acupoints are believed to be activated, which is known as acupoint sensitization.

OBJECTIVE

This study aimed to investigate the major manifestations of acupoint sensitization in patients with chronic low back pain (cLBP) to provide better understanding of acupoint sensitization phenomena in the context of cLBP.

METHODS

This study was a matched-sample cross-sectional study 16 participants diagnosed with cLBP and 16 healthy controls matched in age, sex, and ethnicity were included. The following aspects of sensitization phenomena of targeted points were compared: pressure pain threshold (PPT), skin temperature, surface electrical conductance, receptive field, and morphological change of skin.

RESULTS

PPT at points of interest were significantly lower in cLBP participants compared with healthy controls (P< 0.05); in addition, receptive field was found to be larger at left BL 23 in cLBP participants (P< 0.05). There was no statistically significant difference in skin temperature, electrical conductance, or morphology between the two groups.

CONCLUSIONS

Reduced PPT at all detected points and enlarged receptive field at left BL 23 were found in cLBP participants. These two features appear key in defining acupoint sensitization in cLBP, and provide evidence for selecting and locating acupuncture points in future clinical studies.

Intraoperative use of the machine learning-derived nociception level monitor results in less pain in the first 90 min after surgery

In this pooled analysis of two randomized clinical trials, intraoperative opioid dosing based on the nociception level-index produced less pain compared to standard care with a difference in pain scores in the post-anesthesia care unit of 1.5 (95% CI 0.8-2.2) points on an 11-point scale. The proportion of patients with severe pain was lower by 70%. Severe postoperative pain remains a significant problem and associates with several adverse outcomes. Here, we determined whether the application of a monitor that detects intraoperative nociceptive events, based on machine learning technology, and treatment of such events reduces pain scores in the post-anesthesia care unit (PACU). To that end, we performed a pooled analysis of two trials in adult patients, undergoing elective major abdominal surgery, on the effect of intraoperative nociception level monitor (NOL)-guided fentanyl dosing on PACU pain was performed. Patients received NOL-guided fentanyl dosing or standard care (fentanyl dosing based on hemodynamic parameters). Goal of the intervention was to keep NOL at values that indicated absence of nociception. The primary endpoint of the study was the median pain score obtained in the first 90 min in the PACU. Pain scores were collected at 15 min intervals on an 11-point Likert scale. Data from 125 patients (55 men, 70 women, age range 21-86 years) were analyzed. Sixty-one patients received NOL-guided fentanyl dosing and 64 standard care. Median PACU pain score was 1.5 points (0.8-2.2) lower in the NOL group compared to the standard care; the proportion of patients with severe pain was 70% lower in the NOL group (p = 0.045). The only significant factor associated with increased odds for severe pain was the standard of care compared to NOL treatment (OR 6.0, 95% CI 1.4 -25.9, p = 0.017). The use of a machine learning-based technology to guide opioid dosing during major abdominal surgery resulted in reduced PACU pain scores with less patients in severe pain.

Preliminary Evidence for the Sequentially Mediated Effect of Racism-Related Stress on Pain Sensitivity Through Sleep Disturbance and Corticolimbic Opioid Receptor Function

Sleep disturbance predicts worse pain outcomes. Because sleep disturbance inequitably impacts Black adults - with racism as the upstream cause - understanding how racism-related stress impacts pain through sleep might help minimize racialized pain inequities. This preliminary study examined sequential mediation of the effect of racism-related stress on experimental pain through sleep disturbance and corticolimbic μOR function in pain-free non-Hispanic Black (NHB) and White (NHW) adults. Participants completed questionnaires, actigraphy, positron emission tomography, and sensory testing. We reproduced findings showing greater sleep disturbance and pain sensitivity among NHB participants; greater sleep disturbance (r = .35) and lower pain tolerance (r=-.37) were significantly associated with greater racism-related stress. In a sequential mediation model, the total effect of racism-related stress on pain tolerance (β=-.38, P = .005) weakened after adding sleep disturbance and ventromedial prefrontal cortex (vmPFC) μOR binding potential (BPND) as mediators (β = -.18, P = .16). The indirect effect was statistically significant [point estimate = -.003, (-.007, -.0003). Findings showed a potential sequentially mediated effect of racism-related stress on pain sensitivity through sleep disturbance and vmPFC μOR BPND. As policy efforts are enacted to eliminate the upstream cause of systemic racism, these results cautiously suggest that sleep interventions within racism-based trauma informed therapy might help prevent downstream effects on pain. PERSPECTIVE: This preliminary study identified the effect of racism-related stress on pain through sleep disturbance and mu-opioid receptor binding potential in the ventromedial prefrontal cortex. Findings cautiously support the application of sleep interventions within racism-based trauma-informed therapy to prevent pain inequities as policy changes function to eliminate all levels of racism.

The Experience of BIPOC Living with Chronic Pain in the USA: Biopsychosocial Factors that Underlie Racial Disparities in Pain Outcomes, Comorbidities, Inequities, and Barriers to Treatment

PURPOSE OF REVIEW

This review synthesizes recent findings related to the biopsychosocial processes that underlie racial disparities in chronic pain, while highlighting opportunities for interventions to reduce disparities in pain treatment among BIPOC.

RECENT FINDINGS

Chronic pain is a prevalent and costly public health concern that disproportionately burdens Black, Indigenous, and people of color (BIPOC). This unequal burden arises from an interplay among biological, psychological, and social factors. Social determinants of health (e.g., income, education level, and lack of access or inability to utilize healthcare services) are known to affect overall health, including chronic pain, and disproportionately affect BIPOC communities. This burden is exacerbated by exposure to psychosocial stressors (i.e., perceived injustice, discrimination, and race-based traumatic stress) and can affect biological systems that modulate pain (i.e., inflammation and pain epigenetics). Further, there are racial/ethnic disparities in pain treatment, perpetuating the cycle of undermanaged chronic pain among BIPOC.

Biological sex influences psychological aspects of the biopsychosocial model related to chronic pain intensity and interference among South Korean patients with chronic secondary musculoskeletal pain in rheumatic diseases

Introduction

Pain is a prominent contributor to negative personal and social outcomes, including increased disability and mortality, in many rheumatic diseases. In the Biopsychosocial model of chronic pain, psychological and social factors share roles with the biology of the injury in determining each patient's pain and suffering. The current study explored factors associated with clinical pain intensity and interference among patients with chronic secondary musculoskeletal pain in rheumatic diseases.

Methods

In total, 220 patients experiencing chronic secondary musculoskeletal pain participated. Biological factors (age, biological sex, pain condition, pain duration, pain sensitivity, and comorbidity), socio-economic factors, psychological factors (pain catastrophizing and depressive symptoms), and pain intensity and interference were measured. Descriptive, multivariable linear regression and partial correlation analyses were conducted. Subgroup analysis by sex was conducted to examine differences in how different factors affect the pain experience.

Results

The mean age of the participants was 52.3 years (SD = 12.07) and ranged from 22 to 78. Average pain intensity was 3.01 (0-10 scale) and average total pain interference score was 21.07 (0-70 scale). Partial correlation found positive correlations between pain intensity and interference with depression (intensity: R = 0.224; p = 0.0011; interference: R = 0.351; p < 0.001) and pain catastrophizing (intensity: R = 0.520; p < 0.001; interference: R = 0.464; p < 0.001). In males, pain condition (β = -0.249, p = 0.032) and pain catastrophizing (R = 0.480, p < 0.001) were associated with pain intensity. In males, the simple correlation between pain intensity and depression (R = 0.519; p < 0.001) was driven by pain catastrophizing. In females, pain catastrophizing (R = 0.536, p < 0.001) and depressive symptoms (R = 0.228, p = 0.0077) were independently associated with pain intensity. Age (β = -0.251, p = 0.042) and pain catastrophizing (R = 0.609, p < 0.001) were associated with pain interference in males, while depressive symptoms (R = 0.439, p < 0.001) and pain catastrophizing (R = 0.403, p < 0.001) were associated with pain interference in females. Again, in males, the simple correlation between pain interference and depression (R = 0.455; p < 0.001) was driven by pain catastrophizing.

Discussion

In this study, females were more directly affected by depressive symptoms than males, regarding pain intensity and interference. Pain catastrophizing was a significant factor influencing chronic pain for both males and females. Based on these findings, a sex-specific approach to the Biopsychosocial model should be considered in understanding and managing pain among Asians with chronic secondary musculoskeletal pain.

A qualitative assessment of factors contributing to Spanish-speaking federally qualified health center patients' chronic pain experiences

People of Hispanic or Latino ethnicity (Latinx people) experience pain diagnosis, treatment, and care disparities relative to non-Latinx Whites. Those whose preferred language is Spanish may experience additional disparities when receiving care in a language-discordant environment. In order to better understand medically underserved Spanish-speaking Latinx patients' pain care experience in primary care, we conducted semi-structured qualitative interviews with federally qualified health center staff members (n = 9) and Spanish-speaking adult Latinx patients with chronic pain (n = 12) to capture data on their perspectives. Interview data were mapped to the individual (microsystem), interpersonal (mesosystem), organizational (exosystem), and environmental (macrosystem) levels of Bronfenbrenner's Ecological Systems Theory and analyzed using thematic content analysis informed by the Framework Method. Findings suggest that Spanish-speaking patients and English-speaking care team members may interpret information about pain state and severity differently, may have misaligned expectations about care, treatment methodologies, and treatment goals, and may experience difficulty forming a mutual understanding during health care encounters due to cross-linguistic and cross-cultural miscommunication. Patients preferred to describe their pain in words rather than with numbers or standardized scales, and both patients and frontline care team members expressed frustration with medical interpretation services, which added time and complexity to visits. Patients and health center staff emphasized the diversity of experiences among Spanish-speaking Latinx people, and the need to account for both linguistic and cultural differences during care encounters. Both groups supported hiring more Spanish-speaking, Latinx healthcare personnel who better resemble the patient population, which has the potential to improve linguistic and cultural concordance and competence, with the aim of improving care outcomes and patient satisfaction. Further study is warranted to examine how linguistic and cultural communication barriers impact pain assessment and treatment in primary care, the extent to which patients feel understood by their care teams, and their confidence in their ability to understand and interpret treatment recommendations.

COVID-Related Distress Is Associated with Increased Menstrual Pain and Symptoms in Adult Women

The COVID-19 pandemic resulted in heightened stress for many individuals, with women reporting more stress than men. Although a large body of evidence has demonstrated that stress, in general, can impact the menstrual cycle, it is not yet clear if COVID-specific stress would impact women's menstrual health. The current study explored the relationship between COVID-related stress and distress and menstrual variables (menstrual pain, number and severity of menstrual symptoms, and menstrual pain interference) in a sample of reproductive-age adult women. Seven-hundred fifteen women completed the initial survey and were re-contacted to complete the same survey three months later. Of those recontacted, 223 completed the follow-up survey. Results indicated that COVID-related stress and distress was associated with higher levels of menstrual pain, more frequent and more severe menstrual symptoms, and greater menstrual pain interference, even after accounting for age, hormonal use, bodily pain, and pain catastrophizing. Our findings suggest that women experience unique vulnerabilities that directly impact their health and functioning, and both research and clinical care should address these symptoms through careful assessment and treatment of menstrual pain and symptoms, particularly during and after periods of high stress and distress.

Clinical Assessment of Mechanical Allodynia in Youth With Complex Regional Pain Syndrome: Development and Preliminary Validation of the Pediatric Tactile Sensitivity Test of Allodynia (Pedi-Sense)

Youth with complex regional pain syndrome (CRPS) commonly experience mechanical allodynia and disability. Assessment of mechanical allodynia is typically binary (present or absent), making it difficult to assess the quality and degree of mechanical allodynia before and after treatment. This study developed and validated the Pediatric Tactile Sensitivity Test of Allodynia (Pedi-Sense) to provide an easy way for rehabilitation clinicians to evaluate mechanical allodynia before and after intensive interdisciplinary pain treatment. The 6 Pedi-Sense items demonstrated adequate internal consistency reliability (CR) at admission (CR = .956) and discharge (CR = .973), reasonably fit the hypothesized linear model of stimulus intensity (P < .0001), and significantly loaded onto a single latent factor, mechanical allodynia (P < .0001), at admission and discharge. Pedi-Sense scores significantly correlated with disability (r_s = .40; P = .004) and pain catastrophizing (r_s = .33; P = .017) at admission. The Pedi-Sense appeared responsive to intervention as participants' total scores improved by 1.44 points (95% CI: .72, 2.15) after IIPT interventions that included daily tactile desensitization. However, test-retest and interrater reliability and the specific contribution of desensitization treatment to the overall success of multi-modal pain rehabilitation still needs to be evaluated. PERSPECTIVE: This article presents the development and preliminary validation of a novel clinical assessment of static and dynamic mechanical allodynia. The Pediatric Tactile Sensitivity Test of Allodynia (Pedi-Sense) allows rehabilitation clinicians to easily evaluate mechanical allodynia at the bedside with minimal training and simple equipment to guide desensitization treatment in clinical settings.

Antiracist symptom science: A call to action and path forward

Nurse scientists recognize the experience of racism as a driving force behind health. However, symptom science, a pillar of nursing, has rarely considered contributions of racism. Our objective is to describe findings within symptom science research related to racial disparities and/or experiences of racism and to promote antiracist symptom science within nursing research. In this manuscript, we use an antiracist lens to review a predominant symptom science theory and literature in three areas of symptom science research-oncology, mental health, and perinatal health. Finally, we make recommendations for increasing antiracist research in symptom science by altering (a) research questions, (b) recruitment methods, (c) study design, (d) data analysis, and (e) dissemination of findings. Traditionally, symptom science focuses on individual level factors rather than broader contexts driving symptom experience and management. We urge symptom science researchers to embrace antiracism by designing research with the specific intent of dismantling racism at multiple levels.

Beyond Black vs White: racial/ethnic disparities in chronic pain including Hispanic, Asian, Native American, and multiracial US adults

ABSTRACT

Previous literature on race/ethnicity and pain has rarely included all major US racial groups or examined the sensitivity of findings to different pain operationalizations. Using data from the 2010 to 2018 National Health Interview Surveys on adults 18 years or older (N = 273,972), we calculated the weighted prevalence of 6 definitions of pain to provide a detailed description of chronic pain in White, Black, Hispanic, Asian, Native American, and multiracial groups. We also estimated modified Poisson models to obtain relative disparities, net of demographic and socioeconomic (SES) factors including educational attainment, family income, and home ownership; finally, we calculated average predicted probabilities to show prevalence disparities in absolute terms. We found that Asian Americans showed the lowest pain prevalence across all pain definitions and model specifications. By contrast, Native American and multiracial adults had the highest pain prevalence. This excess pain was due to the lower SES among Native Americans but remained significant and unexplained among multiracial adults. The pain prevalence in White, Black, and Hispanic adults fell in between the 2 extremes. In this trio, Hispanics showed the lowest prevalence, an advantage not attributable to immigrant status or SES. Although most previous research focuses on Black-White comparisons, these 2 groups differ relatively little. Blacks report lower prevalence of less severe pain definitions than Whites but slightly higher prevalence of severe pain. Net of SES, however, Blacks experienced significantly lower pain across all definitions. Overall, racial disparities are larger than previously recognized once all major racial groups are included, and these disparities are largely consistent across different operationalizations of pain.

Race, ethnicity, and the use of regional anesthesia in cancer patients undergoing open abdominal surgery: A single-center retrospective cohort study

Background

Where applicable, regional anesthesia has been shown to be superior to opioid or non-opioid analgesic modalities alone. However, some studies have shown ethnic-based disparities in the use of regional anesthesia in patients undergoing surgical procedures. In this study of patients who had undergone major oncologic surgery, our main objective was to compare the use of regional anesthesia between patients of different ethnicities.

Methods

A retrospective review of adults who had undergone major open abdominal surgical procedures between 2016 and 2021 was performed. Logistic regression models were used to assess the association between baseline patient characteristics and the use of regional anesthesia.

Results

A total of 4,791 patients were included in the analysis. The median age was 60.5 years [interquartile range, 49, 69], the majority were female (65%), and of American Society of Anesthesiologists Physical Status Class (ASA) 3 (94.7%). Regional anesthesia was used in 2,652 patients (55.4%) and was not associated with race or ethnicity (p = 0.287). Compared to White patients, the odds of regional anesthesia use in other racial/ethnic groups were: Asian {odds ratio (OR) 0.851 [95% confidence interval (CI), 0.660–1.097]; p = 0.2125}, Black/African American [OR 0.807 (95% CI, 0.651–1.001); p = 0.0508], Hispanic/Latino [OR 0.957 (95% CI, 0.824–1.154); p = 0.7676], Other race [OR 0.957 (95% CI, 0.627–1.461); p = 0.8376]. In the multivariable analysis, age [OR 0.995 (95% CI, 0.991–1.000); p = 0.0309] and female gender [OR 1.231 (95% CI, 1.090–1.390); p = 0.0008] were associated with the use of regional anesthesia.

Conclusion

In this single-institution retrospective study of adults who had undergone major open abdominal surgery, the use of regional anesthesia was not associated with race or ethnicity. In the multivariable analysis, age and female gender were associated with the use of regional anesthesia.

Pain is Not a "thing": How That Error Affects Language and Logic in Pain Medicine

Effectiveness in academic and clinical communication depends upon agreement on what words and concepts denote and on the consequent ability to argue logically and accurately. In the pain medicine literature there are many examples of imprecision and confusion in this respect, including misnomers and fallacies in reasoning. This article firstly critically examines some of these misnomers. Identified themes include pain being conceptualised as a "thing," conflation between nociception and pain, and confusion between stimulus and response and between the perspectives of the experiencer and the observer of "pain." Secondly, fallacies in reasoning are identified that contribute to imprecision and confusion. These include reification of pain, attributing to the brain functions that belong to whole organisms, and the illusory truth effect. Thirdly, these themes are identified also in constructs that are shown to be based more on speculation than on fact. Taken together, these observations reveal a need to review and, where necessary, modify terminology and concepts used in Pain Medicine. PERSPECTIVE: This article examines a number of words and constructs commonly found in the pain literature from the perspective of accuracy in terms of their consistency of usage, concordance with fact, degree of speculation and logical argument. A common major theme is the error of considering pain as a "thing" that has agentive properties. A need to clarify much of the language used in Pain Medicine is identified.

Short incision versus minimally invasive surgery with tool-kit for carpal tunnel syndrome release: a prospective randomized control trial to evaluate the anterior wrist pain and time to return to work or activities

Trial design

The prospective randomized controlled trial.

Background

This study compares outcomes in terms of early postoperative anterior wrist pain and time to return to work or activities of daily living of patients who underwent carpal tunnel syndrome (CTS) release with short incision and those who had minimally invasive surgery (MIS) with CTS kits.

Methods

A total of 24 patients diagnosed with primary CTS confirmed with electrodiagnosis at an academic university hospital were randomly assigned into one of two groups of 12 patients each: a short incision group and an MIS with tool-kit group using computer-generated block randomization (block of four). Sequentially numbered, opaque, sealed envelopes were used in the allocation concealment process. In the short incision group, skin was incised longitudinally from Kaplan’s line to the area distal to transverse wrist crease (2.5–4.0 cm) while in the tool-kit group, an incision of less than 2.5 cm. was made using special MIS-CTS kits. Primary outcomes evaluated include visual analogue scale (VAS) measurement of pain intensity in the anterior carpal area both while at rest and while conducting daily activities at the 2nd week postoperatively as well as the time to return to activities of daily living and work. Improvement in the Michigan hand questionnaire (MHQ) score, a secondary outcome, was also measured at the 2nd week postoperatively. Patients, allocator and outcome assessor were blinded.

Results

Demographic data, including preoperative electrodiagnostic severity and occupation, were similar in the two groups. There were no significant differences in terms of VAS of the early postoperative anterior carpal area at rest (p > 0.99), while conducting daily activities (p = 0.89) and time to return to activities of daily living (p = 0.46) and work (p = 0.24). The MHQ score improvement at the 2nd week postoperatively showed no significant difference between the groups (p = 0.95). The MIS wound length in the tool-kit group was significantly shorter than in the short incision group (1.95 vs 2.92 cm, p < 0.01).

Conclusions

There is no difference in early postoperative anterior wrist pain, time to return to work or to activities of daily living between the surgical techniques. Short incision is recommended for benefit in term of cost-effectiveness, while MIS with tool-kit could be preferred in patients who concerned in cosmetic appearance between the surgical techniques.

Trial registration

www.clinicaltrials.in.th (TCTR20200530003). Registered 30 May 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05663-5.

Cybersickness Variability by Race: Findings From 6 Studies and a Mini Meta-analysis

Background

With the influx of medical virtual reality (VR) technologies, cybersickness has transitioned from a nuisance experienced during leisure activities to a potential safety and efficacy concern for patients and clinicians. To improve health equity, it is important to understand any potential differences in cybersickness propensity among demographic groups, including racial groups.

Objective

This study aims to explore whether cybersickness propensity differs across racial groups.

Methods

We collected self-reported cybersickness ratings from 6 racially diverse independent samples within 1 laboratory group (N=931). In these studies, the participants were asked to perform tasks in VR such as traversing environments, pointing at and selecting objects, and interacting with virtual humans.

Results

Significant racial differences in cybersickness were found in 50% (3/6) of studies. A mini meta-analysis revealed that, on average, Black participants reported approximately one-third of SD less cybersickness than White participants (Cohen d=−0.31; P<.001), regardless of the nature of the VR experience. There was no overall difference in reported cybersickness between the Asian and White participants (Cohen d=−0.11; P=.51).

Conclusions

Racial differences in cybersickness indicate that researchers, practitioners, and regulators should consider patient demographics when evaluating VR health intervention outcomes. These findings lay the groundwork for future studies that may explore racial differences in cybersickness directly.