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

The Impact of Primary Language Spoken on the Pain Experience of Children With Cancer

The purpose of the current prospective cohort study was to determine if acculturation, measured by primary language spoken, impacts the pain response of children being treated for cancer during an experimental pain task. Sixty-seven Spanish-speaking and English-speaking children ages 6 to 18 years being treated for cancer provided ratings of pain and upset severity during the completion of the cold pressor task (CPT). One week following the CPT, participants provided their recollection of average pain and upset during the CPT. Repeated measures analysis of variance revealed Spanish-speaking children reported significantly higher pain (F1,64=5.58, P=0.02) and upset (F1,64=7.69, P=0.007) ratings during the CPT compared with English-speaking children. Also, Spanish-speaking children were over 4 times as likely to remove their hands from the water before the CPT 4-minute uninformed ceiling compared with English-speaking children (P=0.002). These findings suggest that cultural and contextual factors, including the level of acculturation, are important considerations in the assessment and management of pain in children with cancer. Future research should continue to examine the mechanisms underlying the association between acculturation and the symptom experience for children receiving treatment for cancer.

Motor Learning in Response to Different Experimental Pain Models Among Healthy Individuals: A Systematic Review

Learning new movement patterns is a normal part of daily life, but of critical importance in both sport and rehabilitation. A major question is how different sensory signals are integrated together to give rise to motor adaptation and learning. More specifically, there is growing evidence that pain can give rise to alterations in the learning process. Despite a number of studies investigating the role of pain on the learning process, there is still no systematic review to summarize and critically assess investigations regarding this topic in the literature. Here in this systematic review, we summarize and critically evaluate studies that examined the influence of experimental pain on motor learning. Seventeen studies that exclusively assessed the effect of experimental pain models on motor learning among healthy human individuals were included for this systematic review, carried out based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. The results of the review revealed there is no consensus regarding the effect of pain on the skill learning acquisition and retention. However, several studies demonstrated that participants who experienced pain continued to express a changed motor strategy to perform a motor task even 1 week after training under the pain condition. The results highlight a need for further studies in this area of research, and specifically to investigate whether pain has different effects on motor learning depending on the type of motor task.

Simple Quantitative Sensory Testing Reveals Paradoxical Co-existence of Hypoesthesia and Hyperalgesia in Diabetes

Background: Diabetic neuropathy is characterized by the paradoxical co-existence of hypo- and hyperalgesia to sensory stimuli. The literature shows consistently sensory differences between healthy and participants with diabetes. We hypothesized that due to differences in pathophysiology, advanced quantitative sensory testing (QST) might reveal sensory discrepancies between type 1 (T1D) and type 2 diabetes (T2D). Furthermore, we investigated whether vibration detection thresholds (VDT) were associated with sensory response.

Method: Fifty-six adults with T1D [43 years (28–58)], 99 adults with T2D [65 years (57–71)], and 122 healthy individuals [51 years (34–64)] were included. VDT, pressure pain detection thresholds (pPDT) and tolerance (pPTT), tonic cold pain (hand-immersion in iced water), and central pain mechanisms (temporal summation and conditioned pain modulation) were tested and compared between T1D and T2D. VDT was categorized into normal (< 18 V), intermediary (18–25 V), or high (> 25 V).

Results: In comparison to healthy, analysis adjusted for age, BMI, and gender revealed hypoalgesia to tibial (pPDT): p = 0.01, hyperalgesia to tonic cold pain: p < 0.01, and diminished temporal summation (arm: p < 0.01; abdomen: p < 0.01). In comparison to participants with T2D, participants with T1D were hypoalgesic to tibial pPDT: p < 0.01 and pPTT: p < 0.01, and lower VDT: p = 0.02. VDT was not associated with QST responses.

Conclusion: Participants with T1D were more hypoalgesic to bone pPDT and pPTT independent of lower VDT, indicating neuronal health toward normalization. Improved understanding of differentiated sensory profiles in T1D and T2D may identify improved clinical endpoints in future trials.

The Negative Effect of Social Discrimination on Pain Tolerance and the Moderating Role of Pain Catastrophizing

This study examined the negative impact of social discrimination on the time to pain tolerance during experimentally induced cold pressor pain among healthy individuals. It was hypothesized that the degree to which one catastrophized about pain would exacerbate the negative impact of a history discriminatory experiences on pain tolerance, and that this interaction would be different between individuals of a racial and ethnic minority and non-Hispanic white individuals (thus testing catastrophizing as a moderated moderator). Higher levels of discrimination were positively related to catastrophic thinking about pain, and there was a significant negative relationship between the level of experienced discrimination and time to pain tolerance. Pain catastrophizing emerged as a significant moderator in that when pain catastrophizing levels were high, there was no association between social discrimination and pain tolerance. A history of social discrimination was significantly associated with reduced pain tolerance at low and moderate levels of pain catastrophizing. Racial minority status did not significantly alter this moderating relationship. Implications for the importance of assessing sociocultural variables, such as experiencing social discrimination in the clinical assessment of the individual with pain are outlined.

Genetic and Clinical Factors Associated with Opioid Response in Chinese Han Patients with Cancer Pain: An Exploratory Cross-Sectional Study

Introduction

Studies have shown that genetic variation and environmental factors are associated with individual differences in therapeutic efficacy and side effects of opioids. However, the focus of these studies has been on a single factor of single-nucleotide polymorphisms (SNPs) or haplotypes, for which results have rarely been validated. For complex traits, such as cancer pain and opioid response, interactions between multiple genetic variation and environmental factors need to be considered to explain the opioid individual differences.

Methods

We conducted an exploratory two-stage cross-sectional study with 1027 Chinese patients who were taking strong opioid medications for their cancer pain, and genotyped 110 SNPs to explore the association of SNPs, haplotypes, gene–gene and gene–environment interactions with opioid dose, pain relief, and opioid-induced constipation.

Results

Due to the failure to meet Benjamini–Hochberg criteria in the discovery stage or to be validated in replication stage, no association was found between SNPs, haplotypes, paired SNP–SNP interactions or multi-dimensional gene–gene interactions and opioid response. However, for gene–environment interactions, optimal models have been constructed in all phenotypes of opioid response.

Conclusions

This study reveals for the first time that construction of multidimensional gene–environment interactions enables better interpretations of the effect of genetic variation and environmental factors on the opioid response in patients with cancer pain.

Trial registration

Chictr.org.cn, identifier, ChiCTR2000033576.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-022-00353-5.

Effectiveness of Acupuncture for Pain Control After Cesarean Delivery: A Randomized Clinical Trial

IMPORTANCE

A pharmacological approach to pain control after cesarean delivery is often insufficient on its own. Acupuncture is a promising method for mitigating postoperative pain and reducing postoperative opioid requirements.

OBJECTIVE

To evaluate the efficacy and effectiveness of acupuncture as an adjunctive therapy for pain control after cesarean delivery, compared with a placebo intervention and standard care alone.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, placebo-controlled, patient- and assessor-blinded randomized clinical trial was conducted from January 13, 2015, to June 27, 2018, at a tertiary university hospital in Greifswald, Germany. Participants were women who were scheduled for elective cesarean delivery under spinal anesthesia and were randomized to either the acupuncture group (n = 60) or placebo group (n = 60). Another 60 consecutive patients who met the eligibility criteria and received the standard postoperative analgesia were selected to form a nonrandomized standard care group. The intention-to-treat analysis was performed from August 19, 2019, to September 13, 2019.

INTERVENTIONS

In addition to standard pain treatment, each patient in the acupuncture group received auricular and body acupuncture with indwelling intradermal needles, whereas patients in the placebo group were treated with nonpenetrating placebo needles.

MAIN OUTCOMES AND MEASURES

The primary outcome was pain intensity on movement, which was measured using an 11-item verbal rating scale. Secondary outcomes were analgesia-related adverse effects, analgesics consumption, time to mobilization and Foley catheter removal, quality of patient blinding to randomization, and patient satisfaction with treatment of pain.

RESULTS

A total of 180 female patients (mean [SD] age, 31 [5] years) were included in the intention-to-treat analysis. The mean pain intensity on movement in the acupuncture group on the first postoperative day was lower than in the placebo group (4.7 [1.8] vs 6.0 [2.0] points; Cohen d, 0.73; 95% CI, 0.31-1.01; P = .001) and the standard care group (6.3 [1.3] points; Cohen d, 1.01; 95% CI, 0.63-1.40; P < .001). On the first postoperative day, 59 patients (98%) in the acupuncture group were fully mobilized vs 49 patients (83%) in the placebo group (relative risk [RR], 1.18; 95% CI, 1.06-1.33; P = .01) and 35 patients (58%) in the standard care group (RR, 1.69; 95% CI, 1.36-2.09; P < .001). The Foley catheter was removed in a total of 57 patients (93%) from the acupuncture group vs 43 patients (72%) from the placebo group (RR, 1.33; 95% CI, 1.12-1.57; P = .003) and 42 patients (70%) from the standard care group (RR, 1.37; 95% CI, 1.14-1.62; P = .002). Other parameters were comparable across the 3 study groups.

CONCLUSIONS AND RELEVANCE

Results of this trial showed that acupuncture was safe and effective in reducing pain and accelerating mobilization of patients after cesarean delivery. With consideration for personnel and time expenditures, acupuncture can be recommended as routine, supplemental therapy for pain control in patients after elective cesarean delivery.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02364167.

Identifying multiple knee pain trajectories and the prediction of opioid and NSAID medication used: A latent class growth approach

BACKGROUND

Knee pain is a major source of distress and disability, with pain progression highly variable between individuals. Previous studies defining pain trajectories have all used a single measure of pain, and these differ across studies. Different measures reflect diverse pain mechanisms. To ascertain the clinical utility of pain trajectories, we explored associations between opioid and non-steroidal anti-inflammatory drug (NSAID) use.

METHODS

We model pain trajectories using two measures-Intermittent and Constant Osteoarthritis Pain (ICOAP) and the painDETECT, in 2141 participants, across 3 waves (the baseline, 1- and 3-year assessments) of the Knee Pain In the Community (KPIC) cohort.

RESULTS

Latent class growth analysis identified six trajectories using ICOAP subscales (High-Stable, Low-Stable, Moderate Worsening, Moderate Recovering, Worsening, and Recovering) and four trajectories using painDETECT (High-stable, Low-stable, Moderate Worsening, and Moderate Recovering). There was a high degree of correspondence between people assigned to pain trajectories between ICOAP intermittent and constant subscales, but less so using painDETECT. Opioid use was associated with ICOAP trajectories only (e.g., High-Stable and Worsening intermittent ICOAP trajectories) and in women.

CONCLUSION

Different measures of pain produce different patterns of pain progression and these are differentially related to medication use. Opioid use is linked to trajectories of pain based on the impact of pain on behavior and not pain symptoms. Thus, managing pain's behavioral impact is more central to understanding opioid use than managing pain symptoms. These findings support more in-depth questioning about the type of pain and its progression in clinical practice.

Neuronal-enriched extracellular vesicles in individuals with IBS: A pilot study of COMT and BDNF

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by abdominal pain, bowel habit alterations, and psychiatric comorbidities. Although pathophysiology remains incompletely understood, prior work demonstrates associations with brain-derived neurotrophic factor (BDNF) and catechol-O-methyltransferase (COMT). The purpose of this study was to quantify BDNF and COMT in plasma and in neuronal-enriched extracellular vesicles (nEVs), assess relationships with psychological symptoms, and gain insight on the brain-gut connection in IBS.

METHODS

Clinical data and biorepository samples from a parent investigation were used, including scores on the Perceived Stress Scale (PSS) and Center for Epidemiological Studies Depression Scale (CES-D). Distinct subpopulations of nEVs were isolated using neural cell adhesion molecule L1CAM; levels of COMT, mature BDNF, and pro-BDNF were quantified in plasma and in nEVs using ELISA.

KEY RESULTS

Data from 47 females (28.11 ± 6.85 years) included 18 IBS and 29 healthy control (HC) participants. IBS participants displayed reduced plasma levels of mature BDNF compared with HC (p = 0.024). Levels of COMT plasma and IBS grouping significantly predicted CES-D scores (p = 0.034). Exploratory analyses by IBS subtype and race revealed African American HC display lower levels of COMT EV than Caucasian HC (p = 0.022).

CONCLUSIONS & INFERENCES

Lower levels of mature BDNF in IBS participants, preliminary patterns detected in cargo content of nEVs, and relevance of COMT and IBS status to CES-D scores, offer insight on depressive symptomatology and brain-gut dysregulation in IBS. Lower COMT levels in nEVs of African Americans highlight the relevance of race when conducting such analyses across diverse populations.

Culture and musculoskeletal pain: strategies, challenges, and future directions to develop culturally sensitive physical therapy care

BACKGROUND

Pain experience has a multidimensional nature. Assessment and treatment recommendations for pain conditions suggest clinicians use biopsychosocial approaches to treat pain and disability. The current pain research is overwhelmingly skewed towards the study of biological and psychological factors including interventions, whereas, cultural factors are often ignored.

OBJECTIVE

The aims of this Masterclass is threefold: (1) to discuss cultural influences on pain, (2) to provide strategies for delivering appropriate pain education and exercises in culturally diverse people with chronic pain, and (3) to present challenges and future directions to clinicians and researchers.

DISCUSSION

Cultural factors have a relevant influence on the way individuals experience and manage health and illness. Thus, people with different cultural experience perceive, respond, communicate and manage their pain in different ways. In this aspect, the contents of pain education should be presented using different culturally appropriate examples, metaphors, images, and delivery methods that may enhance the impact of the message. Efforts should be made to produce and spread culturally adapted evidence-based materials and resources. In addition, a culturally sensitive approach may help to introduce patients to graded activities, so that they can apply these strategies in culturally acceptable and meaningful ways. Future studies should investigate the effectiveness of culturally-adapted interventions in pain-related outcomes in different pain conditions in patients with different cultural backgrounds.

Differential DNA methylation in Black and White individuals with chronic low back pain enrich different genomic pathways

Compared to Non-Hispanic Whites (NHWs), individuals who self-identify as Non-Hispanic Blacks (NHBs) in the United States experience more severe and disabling chronic low back pain (cLBP). We hypothesized that differences in DNA methylation (DNAm) play a role in racial disparities in cLBP.

PURPOSE

To determine the relationship between DNAm levels and racial group differences in adults with cLBP. Our study's secondary purpose was to perform a race-stratified comparison of adults with cLBP and pain-free controls and identify functional genomic pathways enriched by annotated differentially methylated genes.

PATIENTS AND METHODS

We recruited 49 NHBs and 49 NHWs (49 cLBP and 49 pain-free controls, PFCs), analyzed DNAm from whole blood using reduced representation bisulfite sequencing, and identified enriched genomic pathways.

RESULTS

Among participants with cLBP, we identified 2873 differentially methylated loci (DML; methylation differences of at least 10% and p < 0.0001), many of which were annotated to genes of importance to pain pathology. These DMLs significantly enriched pathways to involved in nociception/pain processing (Dopamine-DARPP32 Feedback in cAMP signaling, GABA Receptor Signaling, Opioid Signaling) and neuronal differentiation (e.g., Calcium Signaling, Axon Guidance Signaling, and Endocannabinoid Neuronal Synapse). Our race stratified analyses of individuals with cLBP versus PFCs revealed 2356 DMLs in NHBs and 772 DMLs in NHWs with p < 0.0001 and > 10% methylation difference. Ingenuity Pathway Analysis revealed that many pathways of significance to pain such as Corticotropin Releasing Hormone Signaling, White Adipose Tissue Browning, and GABA Receptor Signaling pathways, were more significant in NHBs than NHWs.

CONCLUSION

Even though an individual's self-identified race is a social construct, not a biological variable, racism associated with that classification affects virtually every aspect of life, including disease risk. DNAm induced alterations in stress signaling pathways may explain worse pain outcomes in NHBs.

Validation and Cross-Cultural Adaptation of the Spanish Version of the Pain Sensitivity Questionnaire (PSQ-S)

Experimental pain testing requires specific equipment and may be uncomfortable for patients. The Pain Sensitivity Questionnaire (PSQ) was developed to assess pain sensitivity, based on the pain intensity ratings (range: 0–10) of painful situations that occur in daily life. The main objective of this study was to carry out a cross-cultural adaptation and validation of the Spanish version of the PSQ (PSQ-S). A total of 354 subjects (296 healthy and 58 chronic pain patients) filled in the PSQ-S. A subgroup of 116 subjects performed experimental pain testing, including two modalities (cold and pressure), with different measures: pain intensity rating, pressure pain threshold, and tolerance. The validation results showed two factors: PSQ-S-moderate and PSQ-S-minor and, for the total scale and the two factors, an excellent internal consistency (Cronbach’s alpha coefficient > 0.9) and a substantial reliability (Intraclass Correlation Coefficient > 0.8). We obtained strong correlations with all the experimental pain rating parameters, catastrophizing, and depression variables, as well as moderate correlations with anxiety, central sensibilization, and impact on the quality of life. Chronic pain patients received elevated PSQ-S scores compared to healthy controls, and three cut-off values (PSQ-S-total = 7.00, PSQ-S-moderate = 7.57, and PSQ-S-minor = 6.29) based on ROC curve analyses were shown to be able to discriminate between healthy adults and adults with chronic pain. Therefore, PSQ-S may be a simple alternative to experimental pain procedures for clinical and experimental pain research.

Play the Pain: A Digital Strategy for Play-Oriented Research and Action

The value of understanding patients' illness experience and social contexts for advancing medicine and clinical care is widely acknowledged. However, methodologies for rigorous and inclusive data gathering and integrative analysis of biomedical, cultural, and social factors are limited. In this paper, we propose a digital strategy for large-scale qualitative health research, using play (as a state of being, a communication mode or context, and a set of imaginative, expressive, and game-like activities) as a research method for recursive learning and action planning. Our proposal builds on Gregory Bateson's cybernetic approach to knowledge production. Using chronic pain as an example, we show how pragmatic, structural and cultural constraints that define the relationship of patients to the healthcare system can give rise to conflicted messaging that impedes inclusive health research. We then review existing literature to illustrate how different types of play including games, chatbots, virtual worlds, and creative art making can contribute to research in chronic pain. Inspired by Frederick Steier's application of Bateson's theory to designing a science museum, we propose DiSPORA (Digital Strategy for Play-Oriented Research and Action), a virtual citizen science laboratory which provides a framework for delivering health information, tools for play-based experimentation, and data collection capacity, but is flexible in allowing participants to choose the mode and the extent of their interaction. Combined with other data management platforms used in epidemiological studies of neuropsychiatric illness, DiSPORA offers a tool for large-scale qualitative research, digital phenotyping, and advancing personalized medicine.

Different priming effects of empathy on neural processing associated with firsthand pain and nonpain perception

The shared-representation model of empathy is still debated. One of the major questions is whether empathy-eliciting stimuli depicting others' pain selectively activate the representations of self-pain. To address this issue, we assessed the priming effects of empathy-eliciting pictures on firsthand pain and nonpain perception, as well as its associated neural processing. In Experiment 1, when compared with nonpainful pictures depicting individuals' body parts with no injury, participants primed by painful pictures showing individuals' body parts with injury reported higher ratings for perceived intensity, unpleasantness, and salience of nociceptive and auditory stimuli, but they only exhibited increased N2 amplitude in response to nociceptive stimuli. In Experiment 2, the results from another group of participants replicated the observations of Experiment 1 and validated the findings in the non-nociceptive somatosensory modality. Importantly, participants' concern ratings for priming pictures predicted their unpleasantness ratings for subsequent nociceptive stimuli, while participants' attention ratings predicted their unpleasantness ratings for subsequent auditory and tactile stimuli. This finding implies that empathy for pain might influence pain and nonpain perception via different psychological mechanisms. In summary, our findings highlight the existence of pain-selective representations in empathy for pain and contribute to a better understanding of the shared-representation model of empathy.

Can We Eliminate Opioids After Anterior Cruciate Ligament Reconstruction? A Prospective, Randomized Controlled Trial

BACKGROUND

Multimodal pain protocols have been effective for postsurgical pain control; however, no published protocol has been effective in eliminating opioid consumption.

PURPOSE

To compare a multimodal nonopioid pain protocol versus traditional opioid medication for postoperative pain control in patients undergoing anterior cruciate ligament reconstruction (ACLR).

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 90 patients undergoing primary ACLR were assessed for participation. We performed a prospective, randomized controlled trial in accordance with the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The study arms were a multimodal nonopioid analgesic protocol (acetaminophen, ketorolac, diazepam, gabapentin, and meloxicam) and a standard opioid regimen (hydrocodone-acetaminophen), and the primary outcome was postoperative visual analog scale (VAS) pain scores for 10 days. Secondary outcomes included patient-reported outcomes, complications, and satisfaction. The observers were blinded, and the patients were not blinded to the intervention.

RESULTS

A total of 9 patients did not meet inclusion criteria, and 19 patients declined participation. Thus, 62 patients were analyzed, with 28 patients randomized to the opioid group and 34 to the multimodal nonopioid group. Patients receiving the multimodal nonopioid pain regimen demonstrated significantly lower VAS scores compared with patients who received opioid pain medication (P < .05). Patients were administered the Patient-Reported Outcomes Measurement and Information System Pain Interference Short Form, and no significant difference was found in patients' preoperative scores (opioid group, 58.6 ± 7.9; multimodal nonopioid group, 57.5 ± 7.4; P = .385) and 1-week postoperative scores (opioid group, 66.3 ± 8.2; multimodal nonopioid group, 61.4 ± 8.8; P = .147). When we adjusted for possible confounders (age, sex, body mass index, graft type), no significant differences in pain control were found between the 2 groups. The most common adverse effects for both groups were drowsiness and constipation, with no difference between the groups. All patients in the multimodal nonopioid group reported satisfactory pain management.

CONCLUSIONS

A multimodal nonopioid pain protocol provided at least equivalent pain control compared with traditional opioid analgesics in patients undergoing ACLR. Minimal side effects, which did not differ between groups, were noted, and all patients reported satisfaction with their pain management.

Are all pain tolerance tasks the same? Convergent validity of four behavioral pain tolerance tasks, self-reported capability for suicide, and lifetime self-injurious behaviors

OBJECTIVES

Discrepancies persist regarding the extent to which different pain measures provide similar information and relate to capability for suicide and self-injurious behaviors. This study examined pain threshold, tolerance, and persistence across four modalities (cold, heat, pressure, shock) and assessed associations with self-reported capability for suicide, non-suicidal self-injury (NSSI), and suicide attempts.

METHODS

A sample of 211 students who reported lifetime suicidal ideation completed four behavioral pain tasks and self-reported on capability for suicide, NSSI, and self-injurious behaviors.

RESULTS

All pain thresholds, tolerances, and persistences were positively correlated across the four tasks. Pain facets were related to self-reported capability for suicide with small effect sizes but generally did not differ across suicide attempt or NSSI histories.

CONCLUSIONS

Pain thresholds, tolerances, and persistences demonstrated convergent validity across the four modalities, suggesting that these tasks provide similar information. Although the relation between pain and self-injurious behaviors remains unclear, these tasks can generally be used interchangeably.

Race-Related Differences Between and Within Sex to Experimental Thermal Pain in Middle and Older Adulthood: An Exploratory Pilot Analysis

This brief report details a pilot analysis conducted to explore racial differences in pain sensitivity and unpleasantness between cognitively healthy Black and White adults, stratified by sex. A total of 24 cognitively healthy adults (12 Black and 12 White) from two completed studies were matched by age and sex, and divided into two groups based on race. Stratified analyses by sex demonstrated that Black females reported experiencing pain intensity ratings of all three intensity sensations at lower temperatures than White females. These findings will inform future research studies to determine if these results hold true in a fully-powered sample and should include mixed methodologies, incorporating neuroimaging data to further assess this phenomenon. Improving pain assessment and management across racial/ethnic groups will help healthcare providers such as nurses and physicians to ensure optimal quality of life for all.

Opioid-Free Thyroid and Parathyroid Operations: Are Patients Satisfied With Pain Control?

BACKGROUND

The aim of this study was to evaluate pain control and patient satisfaction using an opioid-free analgesic regimen following thyroid and parathyroid operations.

METHODS

Surveys were distributed to all postoperative patients following total thyroidectomy, thyroid lobectomy, and parathyroidectomy between January and April 2020. After surgery, patients were discharged without opioids except in rare cases based on patient needs and surgeon judgment. We measured patient-reported Numeric Rating Scale (NRS) pain scores and satisfaction categorically as either satisfied or dissatisfied.

RESULTS

We received 90 of 198 surveys distributed, for a 45.5% response rate. After excluding neck dissections (n = 6) and preoperative opioid use (n = 4), the final cohort included 80 patients after total thyroidectomy (26.3%), thyroid lobectomy (41.3%), and parathyroidectomy (32.5%).The majority reported satisfaction with pain control (87.5%) and the entire surgical experience (95%). A similar proportion of patients reported satisfaction with pain control after total thyroidectomy (90.9%), thyroid lobectomy (90.5%), and parathyroidectomy (80.8%), indicating the procedure did not significantly impact satisfaction with pain control (P = .47). Patients who reported dissatisfaction with pain control were more likely to receive opioid prescriptions (30% vs 2.9%, P < .01), but the majority still reported satisfaction with their entire operative experience (70%).

DISCUSSION

Even with an opioid-free postoperative pain regimen, most patients report satisfaction with pain control after thyroid and parathyroid operations, and those who were dissatisfied with their pain control generally reported satisfaction with their overall surgical experience. Therefore, an opioid-free postoperative pain control regimen is well tolerated and unlikely to decrease overall patient satisfaction.

The role of negative emotions in sex differences in pain sensitivity

Pain perception varies widely among individuals due to the varying degrees of biological, psychological, and social factors. Notably, sex differences in pain sensitivity have been consistently observed in various experimental and clinical investigations. However, the neuropsychological mechanism underlying sex differences in pain sensitivity remains unclear. To address this issue, we quantified pain sensitivity (i.e., pain threshold and tolerance) using the cold pressure test and negative emotions (i.e., pain-related fear, pain-related anxiety, trait anxiety, and depression) using well-established questionnaires and collected magnetic resonance imaging (MRI) data (i.e., high-resolution T1 structural images and resting-state functional images) from 450 healthy subjects. We observed that, as compared to males, females exhibited lower pain threshold and tolerance. Notably, sex differences in pain sensitivity were mediated by pain-related fear and anxiety. Specifically, pain-related fear and anxiety were the complementary mediators of the relationship between sex and pain threshold, and they were the indirect-only mediators of the relationship between sex and pain tolerance. Besides, structural MRI data revealed that the amygdala subnuclei (i.e., the lateral and basal nuclei in the left hemisphere) volumes were the complementary mediators of the relationship between sex and pain-related fear, which further influenced pain sensitivity. Altogether, our results provided a comprehensive picture of how negative emotions (especially pain-related negative emotions) and related brain structures (especially the amygdala) contribute to sex differences in pain sensitivity. These results deepen our understanding of the neuropsychological underpinnings of sex differences in pain sensitivity, which is important to tailor a personalized method for treating pain according to sex and the level of pain-related negative emotions for patients with painful conditions.

A social affective neuroscience lens on placebo analgesia

Pain is a fundamental experience that promotes survival. In humans, pain stands at the intersection of multiple health crises: chronic pain, the opioid epidemic, and health disparities. The study of placebo analgesia highlights how social, cognitive, and affective processes can directly shape pain, and identifies potential paths for mitigating these crises. This review examines recent progress in the study of placebo analgesia through affective science. It focuses on how placebo effects are shaped by expectations, affect, and the social context surrounding treatment, and discusses neurobiological mechanisms of placebo, highlighting unanswered questions and implications for health. Collaborations between clinicians and social and affective scientists can address outstanding questions and leverage placebo to reduce pain and improve human health.

Does music from noise-canceling headphones have a beneficial effect on men undergoing transrectal ultrasound-guided prostate biopsy?

Background

The objective of this study was to evaluate the effect of music with noise-canceling headphones on men undergoing transrectal ultrasound–guided prostate biopsy (TRUSPB) in a prospective randomized study.

Methods

From January to February 2020, 94 men underwent TRUSPB at our institution. They were divided into two groups and wore noise-cancelling headphones—group 1 (n = 47) did not listen to music and group 2 (n = 47) listened to music. We examined the patients’ clinical characteristics and compared the objective and subjective measurements before and after the procedures. Primary outcomes included vital signs, the State-Trait Anxiety Inventory (STAI, 20–80) scale; and the visual analog scale (VAS, 0–10) for the assessments of pain, satisfaction, and willingness to repeat the procedure.

Results

There were no significant differences in patients' characteristics or the prebiopsy status between the groups. Postbiopsy vital signs for objective parameters were statistically similar between the groups; however, the subjective parameters were not. Postbiopsy STAI-state and VAS scores were significantly lower and VAS scores for the patients’ satisfaction and willingness to repeat the procedure were significantly higher in Group 2 than in Group 1 (p = 0.004, p = 0.009, p = 0.004, and p = 0.003, respectively). In addition, changes in the STAI-state score before and after the procedure were significant in Group 2 (p = 0.001).

Conclusions

Music from noise-canceling headphones may have beneficial effects on anxiety, pain, satisfaction, and willingness to repeat the procedure in men undergoing TRUSPB.

Predictors and Consequences of Pediatric Pain Symptom Trajectories: A 14-Year Longitudinal Study

OBJECTIVE

The present study had three primary objectives. First, pain trajectory from early childhood to early adolescence were modeled. Second, we examined how early childhood individual-, parental-, and family-level factors predict pain trajectories. Third, we evaluated consequences of pain trajectories in terms of anxiety and depressive symptoms, and substance use at age 16 years.

DESIGN

The current paper is a secondary data analysis of a multisite longitudinal study. A total of 731 children and their families were followed from ages 2 to 16 years.

METHODS

A growth mixture model (GMM) was used to identify pain trajectories from ages 2 to 14 years.

RESULTS

The GMM revealed three distinct pain trajectories: (1) Low Pain Symptom (n = 572); (2) Increasing Pain Symptom (n = 106); and (3) U-shaped Pain Symptom (n = 53). Children who experienced greater harsh parenting and sleep disturbances in early childhood were more likely to belong to the Increasing Pain Symptom group, and those with greater anxious-depressed symptoms at age 2 years were more likely to belong to the U-shaped Pain Symptom group than the Low Pain Symptom group. Additionally, those youth in the Increasing Pain Symptom group, compared to the Low and U-shaped Pain Symptom groups, showed elevated anxiety symptoms at age 16 years.

CONCLUSIONS

Reducing harsh parenting and children's sleep disturbances could be important targets for preventing pediatric pain problems. Children with increasing pain symptoms may also benefit from learning adaptive pain management skills to lower the risk of developing anxiety problems in late adolescence.

The role of self-evaluated pain sensitivity as a mediator of objectively measured pain tolerance in Native Americans: findings from the Oklahoma Study of Native American Pain Risk (OK-SNAP)

Native Americans (NAs) are at increased risk for chronic pain. One mechanism contributing to this pain disparity could be personal pain beliefs, which may influence actual pain sensitivity. Thus, we examined whether self-evaluated pain sensitivity (SEPS) mediates the relationship between ethnicity [NAs vs. non-Hispanic Whites (NHWs)] and objectively-measured pain tolerance, and whether catastrophic thinking and pain-related anxiety influence these pain beliefs. 232 healthy, pain-free NAs and NHWs completed questionnaires measuring SEPS, catastrophizing, and anxiety. Objective pain tolerance was also assessed. Results suggested: (1) NAs reported higher levels of SEPS, catastrophizing, and anxiety, (2) catastrophizing may have enhanced anxiety and both catastrophizing and anxiety were associated with higher SEPS, and (3) anxiety and SEPS were associated with lower pain tolerance. A significant bootstrapped mediation analysis suggested NAs experienced higher pain-related anxiety, which may have promoted higher SEPS, that in turn reduced pain tolerance. Longitudinal research is needed to confirm this.

Women's Self-Relevant Goal Pursuit in the Presence of Physical Pain: An Intraindividual Variability Approach

OBJECTIVES

Pursuing personal goals that are relevant to one's sense of self is important for adjusting to age-related changes. Experiences of physical pain, however, are thought to threaten both people's sense of self and their pursuit of personal goals. Although a majority of older women experience physical pain, little is known about their day-to-day regulation of their self-relevant goals in the presence of physical pain. The objectives of this study were to explore associations between physical pain and health goal pursuit on a daily basis for women who identified health as a part of their possible selves.

METHODS

We took an intraindividual variability approach to analyze whether there were within- and between-person differences in associations between daily pain and daily health goal progress among 62 women who provided data over the course of 100 days, yielding 4,150 occasions of data.

RESULTS

At the between-person level, women with higher pain on average had lower health goal pursuit on average. At the within-person level, days of higher-than-average pain were associated with lower same-day health goal progress.

DISCUSSION

Our results suggest that pain interrupts regulation of a self-relevant goal at a within-person-not just between-person-daily level. Future work should consider how these daily, within-person, disruptions affect broader identity processes and overall well-being.

Pain Prevalence, Management and Interference Among University Students in South Korea: An Exploratory Cross-Sectional Study

Background

Pain is a global health issue with a significant impact on young adults. Adverse effects caused by inappropriate pain management among university students are related to poor mental/physical health. This study aimed to explore pain prevalence, management, and interference among university students in South Korea.

Methods

Pain intensity, painful body areas, pain management, and pain interference were measured in a convenience sample of 404 students. Descriptive statistics are reported, and a multivariable binomial logistic regression was conducted to reveal factors associated with pain interference.

Results

The prevalence of acute and chronic pain was 73.5%, while 7.8% reported chronic pain (≥ 3 months). Half of university students who experienced pain reported at least four painful body areas. The average pain intensity during the past 6 months was 4.8/10. About 56% of university students who experienced pain used over-the-counter pain pills for pain management. Rest and massage were the most used non-pharmacological pain management strategies. Mood was the most reported pain interference complaint amongst university students. Greater pain interference was associated with longer pain duration, more painful body areas, and greater pain intensity.

Discussion

Pain is highly prevalent among South Korean university students. Pain management programs, including education about appropriate methods of pain relief, should be developed for university students. Attention should be given to university students with widespread acute and chronic pain of high intensity to mitigate the negative impacts caused by pain interference.

Racial-ethnic disparities in pain intensity and interference among middle-aged and older U.S. adults

BACKGROUND

This study aims to better understand differing pain experiences across U.S. racial/ethnic subgroups by estimating racial-ethnic disparities in both pain intensity and domain-specific pain-related interference. To address this issue, we use a nationally-representative sample of non-Hispanic White, non-Hispanic Black, and Hispanic adults ages 50+ who report recently experiencing pain.

METHODS

Using data from the 2010 wave of the Health and Retirement Study (HRS; N=684), we conducted a series of multivariate analyses to assess possible racial/ethnic disparities in pain intensity and seven domains of pain interference, controlling for relevant sociodemographic variables and other health problems.

RESULTS

Black and Hispanic participants reported higher pain intensity than White participants after controlling for socioeconomic status (SES) and other health conditions. Both Black and Hispanic individuals reported more domain-specific pain interference in bivariate analyses. In multivariate analyses, Black (vs. White) participants reported significantly higher levels of pain interference with family-home responsibilities, occupation, sexual behavior, and daily self-care. We did not find significant Hispanic-White differences in the seven pain interference domains, nor did we find Black-White differences in three domains (recreation, social activities, and essential activities).

CONCLUSIONS

Our findings highlight the need for using multi-dimensional measures of pain when assessing for possible pain disparities with respect to race/ethnicity. Future studies on pain interventions should consider contextualizing the pain experience across different racial subgroups to help pain patients with diverse needs, with the ultimate goal of reducing racial/ethnic disparities in pain.

Sources of Individual Differences in Pain

Pain is an immense clinical and societal challenge, and the key to understanding and treating it is variability. Robust interindividual differences are consistently observed in pain sensitivity, susceptibility to developing painful disorders, and response to analgesic manipulations. This review examines the causes of this variability, including both organismic and environmental sources. Chronic pain development is a textbook example of a gene-environment interaction, requiring both chance initiating events (e.g., trauma, infection) and more immutable risk factors. The focus is on genetic factors, since twin studies have determined that a plurality of the variance likely derives from inherited genetic variants, but sex, age, ethnicity, personality variables, and environmental factors are also considered.

Effects of the ABCB1 c.3435C>T (rs1045642) Polymorphism on Heat Pain Perception in Opioid-Free Adults With Chronic Pain

BACKGROUND

The adenosine triphosphate-binding cassette, subfamily B, member 1 gene (ABCB1) encodes P-glycoprotein (P-gp) that influences the intracellular transport of solutes including endogenous opioid peptides. The primary objective of this study was to determine the effects of the ABCB1 polymorphism c.3435C>T (rs10454642) on heat pain (HP) perception in a group of opioid-free adults with chronic pain.

METHODS

Opioid-free adults with chronic pain consecutively admitted to a pain rehabilitation program comprised the study cohort (N = 134). Individuals were genotyped for the c.3435C>T (rs10454642) polymorphism. The polymorphism was analyzed with nonparametric tests using a dominant (cytosine-cytosine [CC] versus cytosine-thymine [CT] + thymine-thymine [TT]) and recessive (CC + CT versus TT) model of allele effects. Quantitative sensory testing was performed using the Computer Aided Sensory Evaluator IV system.

RESULTS

The distribution of genotypes was 22% (N = 29) for CC, 45% (N = 60) for CT, and 33% (N = 45) for TT (Hardy-Weinberg, P > .1). A significant association was observed between the recessive model and HP threshold. Standardized values of HP threshold were significantly greater in the TT group than the CC + CT group (median difference, -0.77; 95% confidence interval [CI], -1.49 to -0.23; P = .005), and the effect size estimate was small (Cliff delta = 0.30). In the dominant model, no significant difference in HP threshold was observed between the CC and CT + TT groups (median difference, -0.45; 95% CI, -1.15 to 0.00; P = .108).

CONCLUSIONS

These results posit that the efflux of endogenous opioid peptides is reduced in individuals with the TT genotype due to lower expression of P-gp, which, in turn, results in higher HP threshold. This study contributes to the emerging understanding of how the ABCB1 c.3435C>T polymorphism contributes to pain perception in opioid-free adults with chronic pain and provides the foundation for investigating the potential effects of this polymorphism on the clinical course of chronic pain.

Sleep and neighborhood socioeconomic status: a micro longitudinal study of chronic low-back pain and pain-free individuals

Individuals with chronic low back pain (cLBP) frequently report sleep disturbances. Living in a neighborhood characterized by low-socioeconomic status (SES) is associated with a variety of negative health outcomes, including poor sleep. Whether low-neighborhood SES exacerbates sleep disturbances of people with cLBP, relative to pain-free individuals, has not previously been observed. This study compared associations between neighborhood-level SES, pain-status (cLBP vs. pain-free), and daily sleep metrics in 117 adults (cLBP = 82, pain-free = 35). Neighborhood-level SES was gathered from Neighborhood Atlas, which provides a composite measurement of overall neighborhood deprivation (e.g. area deprivation index). Individuals completed home sleep monitoring for 7-consecutive days/nights. Neighborhood SES and pain-status were tested as predictors of actigraphic sleep variables (e.g., sleep efficiency). Analyses revealed neighborhood-level SES and neighborhood-level SES*pain-status interaction significantly impacted objective sleep quality. These findings provide initial support for the negative impact of low neighborhood-level SES and chronic pain on sleep quality.

Offset analgesia identifies impaired endogenous pain modulation in pediatric chronic pain disorders

Offset analgesia (OA), a psychophysical test of endogenous pain inhibition, is diminished in many adult chronic pain disorders but OA has not been investigated in youth with chronic pain disorders. This study assessed OA responses in 30 youth with chronic primary and secondary pain disorders and 32 healthy controls. The OA, control, and constant thermal tests were evoked with an individualized noxious heat stimulus of approximately 50/100 mm on a visual analogue scale followed by 1°C offset temperature. This study also examined the association of OA responses with 2 self-report measures of pain sensitivity, the Central Sensitization Inventory (CSI) and Pain Sensitivity Questionnaire. Patients exhibited diminished capacity to activate OA with a reduction in ΔeVASc of 53 ± 29% vs controls 74 ± 24% (P = 0.003) even after multivariate regression adjusting for age, sex, and body mass index. Patients also showed decreased ability to habituate to a constant noxious heat stimulus compared to controls (P = 0.021). Central Sensitization Inventory scores showed excellent predictive accuracy in differentiating patients from controls (area under the curve = 0.95; 95% CI: 0.91-0.99) and CSI score ≥30 was identified as an optimal cutoff value. Pain Sensitivity Questionnaire scores did not differentiate patients from controls nor correlate with OA. In this study, 60% of youth with chronic pain showed reduced capacity for endogenous pain inhibition.

Clinician-Patient Racial/Ethnic Concordance Influences Racial/Ethnic Minority Pain: Evidence from Simulated Clinical Interactions

OBJECTIVE

Racial and ethnic minorities in the United States report higher levels of both clinical and experimental pain, yet frequently receive inadequate pain treatment. Although these disparities are well documented, their underlying causes remain largely unknown. Evidence from social psychological and health disparities research suggests that clinician-patient racial/ethnic concordance may improve minority patient health outcomes. Yet whether clinician-patient racial/ethnic concordance influences pain remains poorly understood.

METHODS

Medical trainees and community members/undergraduates played the role of "clinicians" and "patients," respectively, in simulated clinical interactions. All participants identified as non-Hispanic Black/African American, Hispanic white, or non-Hispanic white. Interactions were randomized to be either racially/ethnically concordant or discordant in a 3 (clinician race/ethnicity) × 2 (clinician-patient racial/ethnic concordance) factorial design. Clinicians took the medical history and vital signs of the patient and administered an analogue of a painful medical procedure.

RESULTS

As predicted, clinician-patient racial/ethnic concordance reduced self-reported and physiological indicators of pain for non-Hispanic Black/African American patients and did not influence pain for non-Hispanic white patients. Contrary to our prediction, concordance was associated with increased pain report in Hispanic white patients. Finally, the influence of concordance on pain-induced physiological arousal was largest for patients who reported prior experience with or current worry about racial/ethnic discrimination.

CONCLUSIONS

Our findings inform our understanding of the sociocultural factors that influence pain within medical contexts and suggest that increasing minority, particularly non-Hispanic Black/African American, physician numbers may help reduce persistent racial/ethnic pain disparities.

Ethnic disparities in pain processing among healthy adults: μ-opioid receptor binding potential as a putative mechanism

Although ethnic differences in pain perception are well documented, the underlying mechanism for these outcomes has not been established. µ-opioid receptor (MOR) function might contribute to this disparity, given that MORs play a key role in pain sensitivity and modulation. However, no study has characterized ethnic differences in MOR physiology. This study sought to address this knowledge gap by examining differences in µ-selective agonist binding potential (BPND; [C]-Carfentanil) between 27 non-Hispanic black (NHB) and 27 demographically similar, non-Hispanic white participants. Participants completed questionnaires and two 90-minute high-resolution research tomograph positron emission tomography (PET) imaging sessions. During PET imaging, a capsaicin or control cream was applied to individuals' arms, and pain ratings were collected. Bonferroni-corrected PET volumes of interest analyses revealed significantly greater [C]-Carfentanil BPND among NHB participants in bilateral ventral striatum ([left]: F1,52 = 16.38, P < 0.001; [right]: F1,52 = 21.76, P < 0.001), bilateral dorsolateral prefrontal cortex ([left] F1,52 = 17.3, P < 0.001; [right]: F1,52 = 14.17, P < 0.001), bilateral subgenual anterior cingulate cortex ([left]: F1,52 = 10.4, P = 0.002; [right]: F1,52 = 12.91, P = 0.001), and right insula (F1,52 = 11.0, P = 0.002). However, there were no significant main effects of condition or ethnicity × condition interaction effects across models, likely attributable to individual variability in the direction of change within groups. BPND values were significantly correlated with pain ratings collected during the capsaicin condition (r range = 0.34-0.46, P range = 0.01-0.001). Results suggest that NHB individuals might have generally greater unoccupied MOR density than non-Hispanic white peers. Findings have implications for physiological differences underlying ethnicity-related pain disparities. If replicated, these results further emphasize the need for tailored treatments in historically underserved populations.

The Adaptation of Pain Assessment Tools from High-Income to Low- and Middle-Income Countries: Psychometric Properties of a Set of Chronic Pain Questionnaires in Mongolian and New Zealand Patient Samples

OBJECTIVE

Chronic pain is a leading cause of disability in low- and middle-income countries; however, pain assessment tools have generally been developed and validated in high-income countries. This study examines the psychometric properties of a set of translated pain (and distress) questionnaires in Mongolia and documents the characteristics of people seeking treatment for chronic pain in Mongolia, compared with those in New Zealand, which is representative of high-income countries.

DESIGN

Cross-sectional, observational.

SETTING

Hospital-based pain treatment centers in New Zealand and Mongolia.

SUBJECTS

People seeking treatment for chronic pain in Mongolia (N = 142) and New Zealand (N = 159).

METHODS

The Brief Pain Inventory, the Depression Anxiety Stress Scale-21, the Pain Catastrophizing Scale, and the Pain Self-Efficacy Questionnaire were translated into Mongolian and administered to patients attending a hospital-based pain service. Questionnaires that were completed by patients in New Zealand were used for comparisons. Internal reliability, convergent validity, and factor structure were assessed in both groups.

RESULTS

Patients in Mongolia were older and reported lower pain intensity, interference, and distress and higher pain self-efficacy than those in New Zealand. The translated questionnaires had good internal consistencies, and the relationships between pain variables were similar across both groups. The factor structure for the Pain Catastrophizing Scale was consistent across both groups, but this was not the case for the Brief Pain Inventory or the Depression Anxiety Stress Scale-21.

CONCLUSIONS

Findings indicate that some pain outcome measures may be appropriate for use in Mongolia and should be investigated in other low- and middle-income countries.

Pain Prevalence, Chronicity and Impact Within Subpopulations Based on Both Hispanic Ancestry and Race: United States, 2010-2017

We provide national surveillance estimates of pain chronicity, severity and impact in adult subpopulations defined by both Hispanic Ancestry and Race. Data are from 144,434 adults who completed validated questionnaires in the 2010-2017 National Health Interview Survey asking about pain status within the last 3 (N = 84,664) or 6 months (N = 59,770). Multivariable logistic regression was used to assess the relationship between pain and ethnicity/race. Compared to White Puerto Rican participants, White participants with Central/South American and Mexican ancestry had reduced odds of reporting Category 3-4 pain and High-Impact Chronic Pain (HICP), while those of Cuban ancestry had reduced odds of only HICP - eg, White participants with Mexican ancestry had 32% lower odds of having Category 3-4 pain and 50% lower odds of having HICP. While no differences were seen between White Puerto Rican and White Non-Hispanic participants for Category 3-4 pain, White Non-Hispanics had 40% lower odds of reporting HICP. Asian Non-Hispanic and Black Non-Hispanic participants had significantly lower odds of reporting Category 3-4 pain and HICP compared to White Puerto Rican participants, eg, Black Non-Hispanic participants had 26% lower odds off having Category 3-4 pain and 42% lower odds of having HICP. Perspective: By examining pain status in discrete demographic groups based on Hispanic Ancestry and Race, this report further documents substantial difference in health status among underserved populations and provides a baseline for continuing surveillance research on pain, with the eventual goal of eliminating disparities in pain assessment and treatment.

Cross-sectional study of psychosocial and pain-related variables among patients with chronic pain during a time of social distancing imposed by the coronavirus disease 2019 pandemic

ABSTRACT

The COVID-19 pandemic has had a tremendous impact, including on individuals with chronic pain. The social distancing policies necessary to slow the spread of SARS-CoV-2 have involved increased levels of social isolation. This cross-sectional survey study examined pain severity and interference among individuals with chronic pain during an early phase of social distancing mandates and identified characteristics of individuals who were most impacted. Approximately 4 to 8 weeks after social distancing mandates commenced in the state of Massachusetts, 150 patients with fibromyalgia, chronic spine, and postsurgical pain completed demographic, pain, social distancing, and validated psychosocial questionnaires. Patients self-reported an overall significant increase in pain severity and pain interference, compared with before social distancing, although both pain severity and interference were quite variable among individuals under conditions of social distancing. Several demographic, socioeconomic, and psychosocial factors were associated with greater pain severity and interference during social distancing. Multivariable linear regression demonstrated that female sex, nonwhite race, lower education, disability, fibromyalgia, and higher pain catastrophizing were independently associated with greater pain severity, while female sex and pain catastrophizing were independently associated greater pain interference. The findings suggest that individual differences among patients with chronic pain should be considered in the planning, development, and prioritization of interventions to improve pain care and to prevent worsening of symptoms during the continuing COVID-19 pandemic.

Cut-off points between pain intensities of the postoperative pain using receiver operating characteristic (ROC) curves

Background

Pain assessment and management are important in postoperative circumstances as overdosing of opioids can induce respiratory depression and critical consequences. We aimed this study to check the reliability of commonly used pain scales in a postoperative setting among Korean adults. We also intended to determine cut-off points of pain scores between mild and moderate pain and between moderate and severe pain by which can help to decide to use pain medication.

Methods

A total of 180 adult patients undergoing elective non-cardiac surgery were included. Postoperative pain intensity was rated with a visual analog scale (VAS), numeric rating scale (NRS), faces pain scale revised (FPS-R), and verbal rating scale (VRS). The VRS rated pain according to four grades: none, mild, moderate, and severe. Pain assessments were performed twice: when the patients were alert enough to communicate after arrival at the postoperative care unit (PACU) and 30 min after arrival at the PACU. The levels of agreement among the scores were evaluated using intraclass correlation coefficients (ICCs). The cut-off points were determined by receiver operating characteristic curves.

Results

The ICCs among the VAS, NRS, and FPS-R were consistently high (0.839–0.945). The pain categories were as follow: mild ≦ 5.3 / moderate 5.4 ~ 7.1 /severe ≧ 7.2 in VAS, mild ≦ 5 / moderate 6 ~ 7 / severe ≧ 8 in NRS, mild ≦ 4 / moderate 6 / severe 8 and 10 in FPS-R. The cut-off points for analgesics request were VAS ≧ 5.5, NRS ≧ 6, FPS-R ≧ 6, and VRS ≧ 2 (moderate or severe pain).

Conclusions

During the immediate postoperative period, VAS, NRS, and FPS-R were well correlated. The boundary between mild and moderate pain was around five on 10-point scales, and it corresponded to the cut-off point of analgesic request. Healthcare providers should consider VRS and other patient-specific signs to avoid undertreatment of pain or overdosing of pain medication.

Open-Label Placebo Trial among Japanese Patients with Chronic Low Back Pain

Background

The aim of this study was to confirm the effectiveness of open-label placebo (OLP) in Japanese patients with chronic low back pain (CLBP), similar to previous reports, and to investigate its short- and medium-term effects in this study population.

Methods

Fifty-two patients with CLBP were randomized into a treatment as usual (TAU) group (n = 26) or an OLP + TAU group (n = 26) for 12 weeks. The TAU included advice to remain active and exercise in conjunction with recent psychological education based on a self-management strategy. In contrast, participants in the OLP + TAU group were instructed to take two OLP capsules a day. Outcome measures were assessed at baseline and at weeks 3 and 12 using the Roland–Morris Disability Questionnaire (RMDQ), Numerical Rating Scale (NRS) for pain intensity, and the Timed-Up-and-Go (TUG) test. Difference in outcomes between the two groups was compared at the two follow-up points.

Results

Although all participants completed the 3-week follow-up, four patients (two in each group) were lost to follow-up beyond week 3. There were no significant intergroup differences in changes in the RMDQ score (p=0.40), pain-NRS score (p=0.19), and TUG time (p=0.98) at week 3. Two-way repeated measure analyses of covariance showed significant time-course effects but did not show group effects or any interactions between the time-course and group in terms of the RMDQ score. However, it did not show any effects in the pain-NRS score and TUG time at week 12.

Conclusions

The OLP + TAU group showed no superior findings in comparison with the TAU group after 3 weeks and 12 weeks for Japanese patients with CLBP. Nonetheless, significant improvements in functional disability were observed in both groups.

Persistent and Widespread Pain Among Blacks Six Weeks after MVC: Emergency Department-based Cohort Study

INTRODUCTION

Blacks in the United States experience greater persistent pain than non-Hispanic Whites across a range of medical conditions, but to our knowledge no longitudinal studies have examined the risk factors or incidence of persistent pain among Blacks experiencing common traumatic stress exposures such as after a motor vehicle collision (MVC). We evaluated the incidence and predictors of moderate to severe axial musculoskeletal pain (MSAP) and widespread pain six weeks after a MVC in a large cohort of Black adults presenting to the emergency department (ED) for care.

METHODS

This prospective, multi-center, cohort study enrolled Black adults who presented to one of 13 EDs across the US within 24 hours of a MVC and were discharged home after their evaluation. Data were collected at the ED visit via patient interview and self-report surveys at six weeks after the ED visit via internet-based, self-report survey, or telephone interview. We assessed MSAP pain at ED visit and persistence at six weeks. Multivariable models examined factors associated with MSAP persistence at six weeks post-MVC.

RESULTS

Among 787 participants, less than 1% reported no pain in the ED after their MVC, while 79.8 (95% confidence interval [CI], 77.1 - 82.2) reported MSAP and 28.3 (95% CI, 25.5 - 31.3) had widespread pain. At six weeks, 67% (95% CI, 64, 70%) had MSAP and 31% (95% CI, 28, 34%) had widespread pain. ED characteristics predicting MSAP at six weeks post-MVC (area under the curve = 0.74; 95% CI, 0.72, 0.74) were older age, peritraumatic dissociation, moderate to severe pain in the ED, feeling uncertain about recovery, and symptoms of depression.

CONCLUSION

These data indicate that Blacks presenting to the ED for evaluation after MVCs are at high risk for persistent and widespread musculoskeletal pain. Preventive interventions are needed to improve outcomes for this high-risk group.

Attenuating Pain With the Past: Nostalgia Reduces Physical Pain

Previous work has found that nostalgia, a sentimental longing for the past, is associated with psychological, emotional, and social benefits. Recent research has demonstrated that nostalgic reflection also can improve individuals’ physical health (i.e., exercise) and reduce temperature-related pain. Building on this, two experiments examined how nostalgia can reduce people’s pain perceptions (i.e., reduced severity and increased tolerance). Specifically, Study 1 showed that inducing nostalgia through a writing task decreased perceived pain severity (i.e., intensity) among self-reported chronic pain sufferers. Study 2, in turn, demonstrated that Japanese individuals experienced increased pain tolerance (i.e., the maximum level of pain a person can tolerate) for a pressure algometer task following thoughts of nostalgia (vs. a control prime). This work provides evidence that nostalgic reflection may serve as a psychological resource to reduce the perceived severity of physical pain.

Greater mechanical temporal summation of pain in Latinx-Americans and the role of adverse life experiences

Supplemental Digital Content is Available in the Text.

Latinx-Americans showed greater temporal summation, adversity, and adversity correlates relative to non-Hispanic Whites. Discrimination and lifespan social status change inversely related to summation for Latinx-Americans.

Introduction:

Adverse life experiences disproportionately impact Latinx-Americans and are related to greater chronic pain rates. However, little is known about how adversities interact with central pain mechanisms for the development of later pain among Latinx-Americans.

Objectives:

The current study examined the relationship between adverse life experiences (eg, trauma and ethnic discrimination) and correlates (eg, social status) with mechanical temporal summation of pain (a proxy measure of central sensitization) between pain-free U.S. native Latinx (n = 65) and non-Hispanic White (NHW) (n = 51) adults.

Methods:

Participants completed self-report adverse life experience and correlational measures regarding childhood and adulthood and a mechanical temporal summation protocol.

Results:

Relative to NHWs, Latinx-Americans reported experiencing significantly greater trauma, discrimination, and lower social status during childhood and adulthood, along with greater temporal summation. Contrary to hypotheses, recent and lifetime experiences of ethnic discrimination significantly correlated with less temporal summation among Latinx-Americans. Decreases in objective and subjective social status across the lifespan (childhood to present day) correlated with greater temporal summation for Latinx-Americans. However, r-to-z transformation analyses confirmed that significant adversity and social status correlations observed among the Latinx group did not significantly differ from NHW participants.

Conclusions:

The present findings highlight the complex association between adverse experiences, adverse experience risk factors, and pain for Latinx-Americans. Given the disproportion of experienced pain and adversity among Latinx-Americans, the current findings suggest that a better understanding of the unique adversities for this sample may help elucidate the mechanisms underlying the relationship between adversities, adversity correlates, and pain risk for Latinx-Americans.

Supragastric belching in Japan: lower prevalence and relevance for management of gastroesophageal reflux disease compared to United Kingdom

BACKGROUND

Supragastric belching (SGB) may play a role in the pathophysiology of proton pump inhibitors (PPIs)-refractoriness in gastroesophageal reflux disease (GERD). SGB may be present in up to 40% of reflux symptoms in PPI-refractory GERD. Most reports on SGB have come from Western countries, and little is known about the prevalence and relevance of SGB in Asian refractory GERD patients. This study aimed at comparing the role of SGB in GERD patients in Japan and the UK.

METHODS

We re-analyzed impedance-pH monitoring tracings from patients who were referred to tertiary centers in Japan and the UK due to PPI-refractory reflux symptoms. The prevalence of excessive SGB and the impact of SGB on reflux symptoms were compared between the two countries.

RESULTS

Impedance-pH tracings from124 Japanese and 83 British patients were re-analyzed. Japanese patients were significantly younger and had smaller body mass index than the British (P < 0.001). Japanese patients had significantly lower prevalence of excessive SGB (18.5%) than the UK (36.1%) irrespective of reflux phenotype (P = 0.006). Logistic regression analysis showed that the geographical/cultural difference was the only factor associated with the different prevalence of SGB (odds ratio; 2.91, 95% CI 1.09-7.73, P = 0.032). SGB were related to typical reflux symptoms very rarely in Japan [0% (0-4.9)] compared to the UK [35% (0-54.1)] (P = 0.071).

CONCLUSIONS

The prevalence of SGB and their impact on reflux symptoms is significantly lower in Japan compared to the UK. The difference is not related to reflux parameters but might come from ethnic/cultural factors to be further characterized.

Experimenter- and Infrared Thermography-Derived Measures of Capsaicin-Induced Neurogenic Flare Among Non-Hispanic White and Black Adults

OBJECTIVE

Capsaicin is a widely utilized experimental pain stimulus; however, few studies have reported on ethnic differences in pain responses to capsaicin. The present study used infrared thermography to 1) measure differences in capsaicin-induced neurogenic flare between non-Hispanic black (NHB) and non-Hispanic white (NHW) adults and 2) determine the association between neurogenic flare and secondary hyperalgesia.

METHODS

Fifty-four participants (NHB N = 28) underwent heat/capsaicin sensitization model procedures. Neurogenic flare was examined using experimenter (i.e., subjective) and thermography (i.e., objective) measurements. A typically nonpainful mechanical punctate probe was used to measure secondary hyperalgesia.

RESULTS

Ethnic groups did not significantly differ in age, sex, marital status, or personal income. Although experimenters rated a significantly wider area of capsaicin-related neurogenic flare among NHW compared with NHB participants (F1, 52 = 8.33, P = 0.006), thermography results showed no differences between groups in neurogenic flares (F1, 52 = 0.01, P = 0.93). Further, although NHB individuals reported greater average pain during the capsaicin procedures compared with NHW individuals (NHB = 58.57 [3.67], NHW = 46.46 [3.81]; F2, 51 = 5.19, P = 0.03), the groups did not differ in secondary hyperalgesia (F2, 51 = 0.03, P = 0.86), and ethnicity did not moderate the association between neurogenic flare and secondary hyperalgesia (F3, 50 = 0.24, P = 0.87).

CONCLUSIONS

Findings cautiously support the use of infrared thermography over subjective experimenter report when measuring neurogenic inflammation in diverse samples. However, infrared thermography should not be used as a diagnostic tool for pain, given the lack of association between these factors. Future research is warranted to replicate these findings in a larger and more diverse sample to determine accurate neurogenic inflammation measures across other ethnic minority populations.

Common Biological Modulators of Acute Pain: An Overview Within the AAAPT Project (ACTTION-APS-AAPM Acute Pain Taxonomy)

OBJECTIVE

The ACTTION-APS-AAPM Acute Pain Taxonomy (AAAPT) project relies on the identification of modulators to improve characterization and classification of acute pain conditions. In the frame of the AAAPT effort, this paper presents an overview of common biological modulators of acute pain.

METHODS

Nonsystematic overview.

RESULTS

Females may experience more acute pain than males, but the clinical significance may be modest. Increasing age is associated with decreasing analgesic requirement and decreasing pain intensity after surgery and with higher risk of acute low back pain. Racial and ethnic minorities have worse pain, function, and perceived well-being. Patients with preexisting chronic pain and opioid use are at higher risk of severe acute pain and high opioid consumption. The OPRM1 gene A118G polymorphism is associated with pain severity and opioid consumption, with modest quantitative impact. Most studies have found positive associations between pain sensitivity and intensity of acute clinical pain. However, the strength of the association is unclear. Surgical techniques, approaches, and complications influence postoperative pain.

CONCLUSIONS

Sex, age, race, ethnicity, preexisting chronic pain and opioid use, surgical approaches, genetic factors, and pain sensitivity are biological modulators of acute pain. Large studies with multisite replication will quantify accurately the association between modulators and acute pain and establish the value of modulators for characterization and classification of acute pain conditions, as well as their ability to identify patients at risk of uncontrolled pain. The development and validation of quick, bed-side pain sensitivity tests would allow their implementation as clinical screening tools. Acute nonsurgical pain requires more investigation.