Ethnic differences in physical pain sensitivity: role of acculturation

Reasons for a Lower Rate of Epidural Anesthesia During Birth for Immigrant Women in the Eyes of Medical Staff: A Mixed-Methods Analysis

Various studies have shown that immigrant women in comparison to non-immigrant women of the same parity have lower rates of epidural anesthesia (EDA). Data from two studies on immigrant obstetric care in Berlin, Germany were analyzed to answer the following question: What reasons do the medical staff see for the lower rate of EDA in immigrant women? Between May and August 2017, 34 interviews with obstetricians and midwives in four obstetric clinics in Berlin were conducted on the topic of obstetric care for immigrant women. After anonymizing the more than 20 h of interview material, transcripts were coded with MaxQDa and analyzed according to the qualitative content analysis.The quantitative data is from an online survey conducted between May and October 2017, in all but one obstetric clinic in Berlin with obstetricians and midwives. Regarding the research question, 121 questionnaires could be analyzed. In the online survey, (multiple answers were possible), the top reason for a lower rate of EDA given was mostly fear on the part of the immigrant women (64%). A language barrier, which results in logistic and time constrictions, is mentioned as the second most frequent reason (50%). The explorative analysis of the interviews shows that doctors and midwives regard cultural aspects such as different expectations on the birth experience as a reason for a lower EDA rate. Furthermore, within the medical staff the impression persists that in some cases the companion decides on the behalf of the patient about the application of an EDA, which from time to time is against the wish of the immigrant woman giving birth. In the view of the medical staff, the reasons for a lower rate of EDA during birth for immigrant women were varied. On one side, this is attributed to the wishes of the respective women ("demand") but on the other side this can be attributed to the health care system ("supply"). In the case of a language barrier, the "supply" and the access of EDA for immigrant women is limited and can be then shifted to the German-speaking companion to make a decision regarding EDA ("structural deprivation of self-determination").

Patient Race, Ethnicity, Language, and Pain Severity in Primary Care: A Retrospective Electronic Health Record Study

BACKGROUND

Patient race, ethnicity, and culture including language are intertwined and may influence patient reporting of pain severity.

PURPOSE

To describe documentation of patient's self-reported pain presence and severity by race, ethnicity, and language, specifically, Spanish, Hmong, Lao, or Khmer requiring an interpreter or English.

DESIGN AND SAMPLE

Retrospective, electronic health record clinical data mining study of 79,195 patient visits with documented pain scores from one primary care clinic.

METHODS

Hurdle regression was used to explore the effect of race, ethnicity, and language on the chances of having any pain (vs. no pain) and pain severity for visits with pain scores ≥1, controlling for age, sex, and documentation of a pain diagnosis. Mann-Whitney tests were used to explore the influence of English vs. non-English language on pain severity within a race or ethnicity category.

RESULTS

Pain scores were higher for limited English proficiency, compared with English-speaking, patients within the Asian race or Hispanic/Latino ethnicity category. Older age, female sex, pain diagnosis, Black or African American race, and Spanish or Lao language increased the chance of having any pain. These same factors, plus American Indian or Alaska Native race, contributed to higher pain severity. Asian race, in contrast, decreased the chance of reporting any pain and contributed to lesser pain severity.

CONCLUSIONS

Race, in addition to a new area of focus, language, impacted both the chances of reporting any pain and pain severity. Additional research is needed on the impact of language barriers on pain severity reporting, documentation, and differences in pain outcomes and disparities.

Temporal expectancy induced by the mere possession of a placebo analgesic affects placebo analgesia: preliminary findings from a randomized controlled trial

Research on placebo analgesia usually shows that people experienced a reduction in pain after using a placebo analgesic. An emerging line of research argues that, under some circumstances, merely possessing (but not using) a placebo analgesic could induce placebo analgesia. The current study investigates how temporary expectation of pain reduction associated with different forms of possessing a placebo analgesic affects pain outcomes. Healthy participants (n = 90) were presented with a vial of olive oil (placebo), described as a blended essential oil that blocks pain sensations upon nasal inhalation, and were asked to anticipate the benefits of such analgesic oil to the self (such as anticipating the analgesic oil to reduce their pain). Participants were randomized into one of three different possession conditions: physical-possession condition (participants possessed a tangible placebo analgesic oil, inducing an expectation to acquire analgesic benefit early upon the experience of pain), psychological-possession condition (participants possessed a coupon, which can be redeemed for a placebo analgesic oil, inducing an expectation to acquire analgesic benefit later upon the experience of pain), or no-possession condition. Participants did a cold pressor test (CPT) to experience experimentally-induced pain on their non-dominant hand. Their objective physical pain responses (pain-threshold and pain-tolerance), and subjective psychological pain perception (pain intensity, severity, quality, and unpleasantness) were measured. Results revealed that participants in the physical-possession condition reported greater pain-threshold, F(2, 85) = 6.65, p = 0.002, and longer pain-tolerance, F(2, 85) = 7.19, p = 0.001 than participants in the psychological-possession and no-possession conditions. No significant group difference was found in subjective pain perception. The results of this study can advance knowledge about pain mechanisms and novel pain management.

Persistent Incisional Pain after Noncardiac Surgery: An International Prospective Cohort Study

BACKGROUND

The purpose of this study was to determine the incidence, characteristics, impact, and risk factors associated with persistent incisional pain. The hypothesis was that patient demographics and perioperative interventions are associated with persistent pain.

METHODS

This was a secondary analysis of an international prospective cohort study from 2012 to 2014. This study included patients who were 45 yr of age or older who underwent major inpatient noncardiac surgery. Data were collected perioperatively and at 1 yr after surgery to assess for the development of persistent incisional pain (pain present around incision at 1 yr after surgery).

RESULTS

Among 14,831 patients, 495 (3.3%; 95% CI, 3.1 to 3.6) reported persistent incisional pain at 1 yr, with an average pain intensity of 3.6 ± 2.5 (0 to 10 numeric rating scale), with 35% and 14% reporting moderate and severe pain intensities, respectively. More than half of patients with persistent pain reported needing analgesic medications, and 85% reported interference with daily activities (denominator = 495 in the above proportions). Risk factors for persistent pain included female sex (P = 0.007), Asian ethnicity (P < 0.001), surgery for fracture (P < 0.001), history of chronic pain (P < 0.001), coronary artery disease (P < 0.001), history of tobacco use (P = 0.048), postoperative patient-controlled analgesia (P < 0.001), postoperative continuous nerve block (P = 0.010), insulin initiation within 24 h of surgery (P < 0.001), and withholding nonsteroidal anti-inflammatory medication or cyclooxygenase-2 inhibitors on the day of surgery (P = 0.029 and P < 0.001, respectively). Older age (P < 0.001), endoscopic surgery (P = 0.005), and South Asian (P < 0.001), Native American/Australian (P = 0.004), and Latin/Hispanic ethnicities (P < 0.001) were associated with a lower risk of persistent pain.

CONCLUSIONS

Persistent incisional pain is a common complication of inpatient noncardiac surgery, occurring in approximately 1 in 30 adults. It results in significant morbidity, interferes with daily living, and is associated with persistent analgesic consumption. Certain demographics, ethnicities, and perioperative practices are associated with increased risk of persistent pain.

EDITOR’S PERSPECTIVE

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.

Chronic Pain and Mood Disorders in Asian Americans

Purpose: Pain and mood disorder frequently coexist. Yet, for Asian Americans (AAs), scant information about pain and mood disorder is available. Our aims were to compare (1) the rates of pain and mood disorders and (2) the magnitude of associations between pain and mood disorders between AAs and European Americans (EAs), and across different Asian subgroups. Methods: An analytical data was constructed from the Collaborative Psychiatric Epidemiology Studies (CPES), a representative sample of community-residing U.S. adults (n = 9,871). Pain morbidity was assessed by self-report. Mood disorders, including major depression and anxiety disorders, were assessed using the diagnostic interview. Analysis included descriptive statistics and multivariate logistic regression modeling. All analyses were weighted to approximate the U.S. populations, and controlled for sociodemographic and immigration characteristics. Results: Greater proportion of EAs, compared to AAs, endorsed lifetime pain (56.8% vs. 35.8%). Having life pain disorders elevated the likelihood of lifetime mood disorder by more than 2-folds (weight adjusted odds ratio (WAOR): 2.12, 95% CI: 1.77, 2.55). Having pain disorders over the past 12 months elevated the likelihood of mood disorder in the same time period by more than 3-folds (WAOR: 3.29, 95% CI: 2.02, 5.37) among AAs. The magnitude of the association between pain and psychiatric morbidity were greater in Vietnamese Americans compared to other AAs and EAs. Discussion: The conventional belief that rates of pain and mood disorders are greater in AAs than EAs may need to be further examined. Vietnamese Americans may be particularly vulnerable for experience of comorbid pain and mood disorders.

Differences in Psychosocial Factors and Experimental Pain Sensitivity between Hispanics and non-Hispanic Whites from the U.S.-Mexico Border

PURPOSE

Research suggests that ethnicity is a predictor of pain-related outcomes; however, studies comparing the differences in experimental pain sensitivity between Hispanics and non-Hispanic Whites (NHW) are scarce. This study investigated these differences between Hispanics and NHW from the U.S- Mexico border.

METHODS

Fifty-eight healthy subjects completed the survey packet, which included a demographic and a psychosocial factors questionnaire. Participants underwent quantitative sensory testing which included heat pain threshold, heat pain tolerance, Suprathreshold Heat Pain Response (SHPR), and Conditioned Pain Modulation (CPM). SHPR was induced by repeated thermal stimuli in both thenar eminences. CPM was assessed using SHPR as the experimental stimulus, and cold pressor task as the conditioning stimulus.

RESULTS

Analyses showed significant differences in experimental pain measures believed to be representative of facilitatory pain processing including SHPR, and heat pain threshold, where Hispanics reported significantly higher pain ratings than NHW. Hispanics also reported higher levels of ethnic identity and acculturation. However, these factors were not significantly associated with experimental pain sensitivity.

CONCLUSION

The experimental pain sensitivity and psychosocial factors included in this study differed by ethnic group, where Hispanics reported significantly higher pain ratings, when compared to NHW. However, ethnic identity and acculturation were not associated with these pain-related outcomes. Overall, enhanced understanding by clinicians of pain sensitivity and disparities in the pain experience between ethnic groups allows for increased cultural sensitivity and can be used to optimize pain treatment on an individual-by-individual basis.

Prior Pain Exposure and Mere Possession of a Placebo Analgesic Predict Placebo Analgesia: Findings From a Randomized, Double-Blinded, Controlled Trial

A recent study found that merely possessing a placebo analgesic reduces pain. The current study tested for a possible moderator of this effect. Specifically, does the mere possession of a placebo analgesic affect pain for individuals with and without immediate prior experience with the pain task? Healthy participants (N = 127) were randomized to prior pain (PP) condition or without prior pain (No-PP) condition. In the PP condition, participants first did a preliminary trial of a cold pressor test (CPT) to induce direct experience with this pain stimulus. Then they were randomized to possess an inert cream described as either an analgesic cream or an anti-itch cream (pain-irrelevant control object). Participants then completed the main CPT. In the No-PP condition, participants underwent identical procedures and randomization except that they did not do a preliminary CPT, thus having no immediate prior CPT pain experience. We found a significant prior pain experience and possession status interaction effect on placebo analgesia. Participants in the No-PP condition showed evidence of lower pain when they merely possessed an analgesic cream than an anti-itch cream. Such mere possession effect was not found in the PP condition. The impact of expectancy and emotion on the underlying process are discussed. PERSPECTIVE: This article presents a novel finding that prior pain exposure and mere possession of a placebo analgesic predicted placebo analgesia. It offers a novel perspective on the time course of placebo effect. It provides practical implications on potential pain intervention for clinicians and paradigm design for researchers of placebo study.

Relationship between Acculturative Stress and Pain Catastrophizing in Korean Americans

Acculturative stress is speculated to be a sociocultural factor contributing to pain since cultural beliefs and practices can influence the way patients perceive and respond to pain. However, the relationship between acculturative stress and pain catastrophizing remains poorly understood. Therefore, we examined the relationship between acculturative stress and pain catastrophizing in Korean Americans. We collected survey data from Korean American in Texas (N = 374). Acculturative stress was measured with the Acculturative Stress Scale, and pain catastrophizing was measured with the Pain Catastrophizing Scale. Participants' mean age was 46.89 years, and 63% were women. Bivariate and multivariate statistical analyses indicated that higher acculturative stress may contribute to higher pain catastrophizing (regression coefficient = 1.02, P = 0.04). These findings advance our understanding of sociocultural factors associated with pain in Korean Americans; additional research with a larger sample is warranted for cross-validation.

Merely Possessing a Placebo Analgesic Improves Analgesia Similar to Using the Placebo Analgesic

BACKGROUND

Placebo analgesia studies generally reported that the actual use of a placebo analgesic reduces pain. Yeung, Geers, and Kam found that the mere possession (without use) of a placebo analgesic also reduces pain.

PURPOSE

We investigated the relative effectiveness of using versus possessing a placebo analgesic on pain outcomes.

METHODS

In Study 1a, 120 healthy adults were randomized to either the experimental (EXP) conditions (EXP1: used a placebo analgesic cream, EXP2: possessed a placebo analgesic cream) or control (CO) conditions (CO1: possessed a sham cream, CO2: no cream). All participants underwent a cold pressor test (CPT). Study 1b further delineated the effect of possession from the effect of use. Sixty healthy adults were randomized to either the placebo-possession condition (merely possessed a placebo analgesic cream) or the placebo-possession-use condition (possessed and used a placebo analgesic cream). All participants did a CPT.

RESULTS

In Study 1a, as expected, a placebo effect was found-participants who used a placebo analgesic cream showed better pain outcomes than the two CO groups. Surprisingly, participants who merely possessed a placebo analgesic cream performed equally well as those who actually used it. In Study 1b, participants in the two conditions did not differ in most pain outcomes. Participants who possessed and used a placebo analgesic cream only showed slightly more reduction in pain intensity compared to participants who merely possessed the placebo analgesic cream.

CONCLUSIONS

Our results suggest that merely possessing a placebo analgesic could enhance pain outcomes similar to that of applying the placebo analgesic.

Racial Differences in Perioperative Opioid Utilization in Lumbar Decompression and Fusion Surgery for Symptomatic Lumbar Stenosis or Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To assess for racial differences in opioid utilization prior to and after lumbar fusion surgery for patients with lumbar stenosis or spondylolisthesis.

METHODS

Clinical records from patients with lumbar stenosis or spondylolisthesis undergoing primary <3-level lumbar fusion from 2007 to 2016 were gathered from a comprehensive insurance database. Records were queried by International Classification of Diseases diagnosis/procedure codes and insurance-specific generic drug codes. Opioid use 6 months prior, through 2 years after surgery was assessed. Multivariate regression analysis was employed to investigate independent predictors of opioid use following lumbar fusion.

RESULTS

A total of 13 257 patients underwent <3-level posterior lumbar fusion. The cohort racial distribution was as follows: 80.9% white, 7.0% black, 1.0% Hispanic, 0.2% Asian, 0.2% North American Native, 0.8% "Other," and 9.8% "Unknown." Overall, 57.8% patients utilized opioid medications prior to index surgery. When normalized by the number opiate users, all racial cohort saw a reduction in pills disbursed and dollars billed following surgery. Preoperatively, Hispanics had the largest average pills dispensed (222.8 pills/patient) and highest average amount billed ($74.67/patient) for opioid medications. The black cohort had the greatest proportion of patients utilizing preoperative opioids (61.8%), postoperative opioids (87.1%), and long-term opioid utilization (72.7%), defined as use >1 year after index operation. Multivariate logistic regression analysis indicated Asian patients (OR 0.422, 95% CI 0.191-0.991) were less likely to use opioids following lumbar fusion.

CONCLUSIONS

Racial differences exist in perioperative opioid utilization for patients undergoing lumbar fusion surgery for spinal stenosis or spondylolisthesis. Future studies are needed corroborate our findings.

Sociocultural factors influencing physiotherapy management in culturally and linguistically diverse people with persistent pain: a scoping review

BACKGROUND

People with persistent pain from culturally and linguistically diverse (CALD) communities experience significant health inequities.

OBJECTIVE

To synthesise the sociocultural factors influencing pain management between CALD patients with persistent pain and physiotherapists treating CALD patients.

DATA SOURCES

Major electronic databases MEDLINE, AMED, Scopus, Web of Science, PsycINFO and Google Scholar were searched until July 2018.

STUDY SELECTION

Studies were included if they explored clinical interactions between physiotherapists and patients with persistent pain from diverse ethnocultural backgrounds.

STUDY APPRAISAL

The methodological quality of qualitative and quantitative studies were assessed using the Critical Appraisal Skills Programme (CASP) Checklist and Mixed Methods Appraisal Tool (MMAT) respectively.

SYNTHESIS METHOD

A thematic synthesis approach was used to extract the common themes.

RESULTS

Sixteen articles from 16 studies were included. Eleven studies were qualitative and five studies were quantitative. Ten explored patients' perspectives, four explored physiotherapists' perspectives, and two explored both. Key factors included: (a) language competence; (b) active vs passive coping strategies; (c) gendered influences; (d) cultural-spiritual beliefs, illness perceptions and expression of pain; (e) treatment satisfaction and; (f) barriers to access.

CONCLUSION

Discordant perspectives on causation, pain management approaches, and patient autonomy in management are evident between CALD patients and physiotherapists. Such discordance potentially create stress in the therapeutic alliance and undermines the efficacy of pain management interventions. To mitigate such barriers, it is crucial to foster cultural competence in physiotherapy and equip physiotherapists with opportunities to maximise their sociocultural awareness, knowledge and skill practising physiotherapy in cultural plural societies.

Race-related differences in acute pain complaints among inner-city women: the role of socioeconomic status

Previous research has shown that African Americans (AA) report higher pain intensity and pain interference than other racial/ethnic groups as well as greater levels of other risk factors related to worse pain outcomes, including PTSD symptoms, pain catastrophizing, and sleep disturbance. Within a Conservation of Resources theory framework, we tested the hypothesis that socioeconomic status (SES) factors (i.e., income, education, employment, perception of income meeting basic needs) largely account for these racial/ethnic differences. Participants were 435 women [AA, 59.1%; Hispanic/Latina (HL), 25.3%; Non-Hispanic/White (NHW), 15.6%] who presented to an Emergency Department (ED) with an acute pain-related complaint. Data were extracted from psychosocial questionnaires completed at the participants' baseline interview. Structural equation modeling was used to examine whether racial/ethnic differences in pain intensity and pain interference were mediated by PTSD symptoms, pain catastrophizing, sleep quality, and sleep duration, and whether these mediation pathways were, in turn, accounted for by SES factors. Results indicated that SES factors accounted for the mediation relationships linking AA race to pain intensity via PTSD symptoms and the mediation relationships linking AA race to pain interference via PTSD symptoms, pain catastrophizing, and sleep quality. Results suggested that observed racial/ethnic differences in AA women's pain intensity, pain interference, and common risk factors for elevated pain may be largely due to racial/ethnic differences in SES. These findings highlight the role of social inequality in persistent health disparities facing inner-city, AA women.

Pain and Distraction According to Sensory Modalities: Current Findings and Future Directions

BACKGROUND

This review discusses the findings in the literature on pain and distraction tasks according to their sensory modality. Distraction tasks have been shown to reduce (experimentally induced) acute pain and chronic pain. This can be influenced by nature and by the sensory modalities used in the distraction tasks. Yet the effect on reducing pain according to the sensory modality of the distraction task has received little attention.

METHODS

A bibliographic search was performed in different databases. The studies will be systematized according to the sensory modality in which the distraction task was applied.

RESULTS

The analyzed studies with auditory distractors showed a reduction of acute pain in adults. However, these are not effective at healthy children and in adults with chronic pain. Visual distractors showed promising results in acute pain in adults and children. Similarly, tactile and mixed distractors decreased acute pain in adults.

CONCLUSION

Distraction tasks by diverse sensory modalities have a positive effect on decreasing the perception of acute pain in adults. Future studies are necessary given the paucity of research on this topic, particularly with tactile distractors (there is only one study). Finally, the most rigorous methodology and the use of ecological contexts are encouraged in future research.

Perceived Racial Discrimination and Pain Intensity/Disability Among Economically Disadvantaged Latinos in a Federally Qualified Health Center: The Role of Anxiety Sensitivity

The present study examined the role of anxiety sensitivity (AS; fear of the negative consequences of anxiety) in the relation between perceived racial discrimination and pain-related problems among Latinos seeking health services at a Federally Qualified Health Center. Participants included 145 adult Latinos (87.80% female, M_age = 38.07 years, SD = 11.98, and 96.2% reported Spanish as their first language). Results indicated that perceived racial discrimination was indirectly related to the pain intensity and pain disability through AS. These effects were evident above and beyond the variance accounted for by gender, age, marital status, educational status, employment status, years living in the United States, and number of axis I diagnoses. Overall, the present findings highlight the merit in focusing further scientific attention on the interplay between perceived racial discrimination and AS to better understand and inform interventions to reduce pain problems among Latinos in primary care.

Racial/ethnic differences in experimental pain sensitivity and associated factors - Cardiovascular responsiveness and psychological status

This study evaluated the contributions of psychological status and cardiovascular responsiveness to racial/ethnic differences in experimental pain sensitivity. The baseline measures of 3,159 healthy individuals-non-Hispanic white (NHW): 1,637, African-American (AA): 1,012, Asian: 299, and Hispanic: 211-from the OPPERA prospective cohort study were used. Cardiovascular responsiveness measures and psychological status were included in structural equation modeling based mediation analyses. Pain catastrophizing was a significant mediator for the associations between race/ethnicity and heat pain tolerance, heat pain ratings, heat pain aftersensations, mechanical cutaneous pain ratings and aftersensations, and mechanical cutaneous pain temporal summation for both Asians and AAs compared to NHWs. HR/MAP index showed a significant inconsistent (mitigating) mediating effect on the association between race/ethnicity (AAs vs. NHWs) and heat pain tolerance. Similarly, coping inconsistently mediated the association between race/ethnicity and mechanical cutaneous pain temporal summation in both AAs and Asians, compared to NHWs. The factor encompassing depression, anxiety, and stress was a significant mediator for the associations between race/ethnicity (Asians vs. NHWs) and heat pain aftersensations. Thus, while pain catastrophizing mediated racial/ethnic differences in many of the QST measures, the psychological and cardiovascular mediators were distinctly restrictive, signifying multiple independent mechanisms in racial/ethnic differences in pain.

The Relationship between Acculturation and Experimental Pain Sensitivity in Asian Americans with Knee Osteoarthritis

Multiple studies in healthy populations and clinical samples have shown that ethnic minorities have greater pain sensitivity than their majority counterparts. Acculturation is speculated to be one of the sociocultural factors contributing to pain sensitivity since cultural beliefs and practices can influence the way patients perceive and respond to pain. However, the relationship of acculturation to pain sensitivity in minority populations remains poorly understood. Therefore, in this cross-sectional study, we examined the relationship between acculturation and experimental pain sensitivity in 50 Asian Americans residing in North Central Florida with knee osteoarthritis pain. The Suinn-Lew Asian Self Identity Acculturation Scale was used to assess acculturation, and multimodal quantitative sensory testing was performed to measure experimental sensitivity, including heat pain tolerance, pressure pain threshold, and punctate mechanical pain. Descriptive and regression analyses were performed. Participants' mean age was 55.7 years, and about half of this sample were Korean American (56%). The participants had lived in the United States for 21 years on average. Regression analyses indicated that lower acculturation to American culture may contribute to greater experimental pain sensitivity. Asian Americans who were more acculturated to the American culture had higher heat pain tolerance (beta = 0.61, P=0.01), higher pressure pain threshold (beta = 0.59, P=0.02), and lower ratings of punctate mechanical pain (beta = -0.70, P < 0.01). These findings add to the literature regarding sociocultural factors associated with pain in Asian Americans; additional research with a larger and more diverse sample of Asian Americans is warranted for cross-validation.

Predictors of Cold and Pressure Pain Tolerance in Healthy South African Adults

BACKGROUND

Studies on relationships between sex, ethnicity, and pain have largely emanated from the United States and Europe. We compared cold (CPT) and pressure pain tolerance (PPT) in male and female South Africans of African and European ancestry and assessed whether psychosocial factors (including pain beliefs) predicted differences in pain tolerance.

METHODS

We recruited 106 (62 female) students of African ancestry and 106 (55 female) of European ancestry and subjected them to a cold-pressor test and pressure algometry. Socioeconomic status (SES), pain catastrophizing, depression, anxiety, and pain beliefs were assessed as predictors of pain tolerance.

RESULTS

CPT was lower in students of African compared with European ancestry (for both sexes), and PPT was lower in female than male students (for both ethnicities). Females were very accepting of men expressing pain and males less so. Males of African ancestry were least accepting but still tolerant. Multivariate analysis identified African ancestry, and particularly being a female of African ancestry, as strong predictors of lower CPT. Anxiety was a weak predict or of CPT. Sex was the only strong predictor of PPT on multivariate analysis (PPT females < males), and catastrophizing was a weak predictor. Female sex and African ancestry were strong predictors of acceptance of expression of pain in males. SES was a weak predictor of the Appropriate Pain Behavior Questionnaire-Malescore.

CONCLUSIONS

Despite different cultural and social backgrounds from US and European cohorts, we saw similar patterns of sex and ethnic differences in CPT and PPT in an African cohort. Traditional psychosocial predictors of pain sensitivity predicted variation in the outcome variables but were not strong predictors.

Depression and Pain in Asian and White Americans With Knee Osteoarthritis

Few studies have examined the underlying psychosocial mechanisms of pain in Asian Americans. Using the biopsychosocial model, we sought to determine whether variations in depression contribute to racial group differences in symptomatic knee osteoarthritis pain between Asian Americans and non-Hispanic white Americans. The sample consisted of 100 participants, including 50 Asian Americans (28 Korean Americans, 9 Chinese Americans, 7 Japanese Americans, 5 Filipino Americans, and 1 Indian American) and 50 age- and sex-matched non-Hispanic white Americans with symptomatic knee osteoarthritis pain. The Centers for Epidemiologic Studies Depression Scale was used to assess symptoms of depression, and the Western Ontario and McMaster Universities Osteoarthritis Index and the Graded Chronic Pain Scale were used to measure clinical pain. In addition, quantitative sensory testing was used to measure experimental sensitivity to heat- and mechanically-induced pain. The results indicated that higher levels of depression in Asian Americans may contribute to greater clinical pain and experimental pain sensitivity. These findings add to the growing literature regarding ethnic and racial differences in pain and its associated psychological conditions, and additional research is warranted to strengthen these findings.

PERSPECTIVE

This article shows the contribution of depression to clinical pain and experimental pain sensitivity in Asian Americans with knee osteoarthritis. Our results suggest that Asian Americans have higher levels of depressive symptoms and that depression plays a relevant role in greater clinical pain and experimental pain sensitivity in Asian Americans.

Different pain responses to chronic and acute pain in various ethnic/racial groups

AIM

Our goal in this study was to review the similarities and differences among ethnic groups and their respective responses to acute and chronic clinically related and experimentally induced pain.

METHOD

In this review, the PUBMED and Google-Scholar databases were searched to analyze articles that have assessed the variations in both acute and chronic pain responses among different ethnic/racial groups.

RESULTS

According to the results from 42 reviewed articles, significant differences exist among ethnic-racial groups for pain prevalence as well as responses to acute and chronic pain. Compared with Caucasians, other ethnic groups are more susceptible to acute pain responses to nociceptive stimulation and to the development of long-term chronic pain.

CONCLUSION

These differences need to be addressed and assessed more extensively in the future in order to minimize the pain management disparities among various ethnic-racial groups and also to improve the relationship between pain management providers and their patients.

Comparing the Safety and Efficacy of Celecoxib for the Treatment of Osteoarthritis in Asian and non-Asian Populations: An Analysis of Data from Two Randomized, Double-blind, Placebo-controlled, Active-comparator Trials

Introduction

Celecoxib is an effective treatment for pain associated with osteoarthritis. There are differences in patient demographics among ethnic groups, with Asian populations typically smaller in body size. As a consequence, there may be a perception that celecoxib is less effective, or has poorer tolerability in Asian patients.

Methods

This analysis compares data from two multicenter, randomized, double-blind, placebo-controlled, active-comparator trials of celecoxib for the treatment of osteoarthritis of the knee: one study in Asian patients and the other in a mixed population comprised mostly of non-Asian patients (from which Asian patients were excluded for this analysis). Each trial was of similar design, with patients randomized 2:2:1 to 6 weeks treatment with celecoxib 200 mg once daily, active comparator (naproxen 500 mg twice daily or ibuprofen 800 mg three times daily), or placebo. The primary efficacy endpoint in each trial was the change from baseline to week 6 in the Patient’s Assessment of Arthritis Pain, as measured on a visual analog scale.

Results

In total, 329 patients were included in the efficacy analysis, 179 in the Asian study and 150 in the non-Asian study. The Asian population was significantly older and smaller in body size (P < 0.0001). There was no significant difference between the Asian and non-Asian populations in change in pain score (95% confidence interval) at study endpoint with celecoxib [−1.1 (−7.7, 5.5); P = 0.7400] or placebo [−5.2 (−14.8, 4.4); P = 0.2870]. There were also no notable differences in safety outcomes between populations.

Conclusions

Due to the smaller size of some Asian patients with OA, physicians may be tempted to decrease the dose of celecoxib below the therapeutic range recognized by regulatory authorities; these data suggest that dose changes are not necessary.

Funding

Pfizer Inc.

Effects of acculturation, coping strategies, locus of control, and self-efficacy on chronic pain: study of Chinese immigrant women in Italy - insights from a thematic field analysis

Chronic pain represents a common public health concern worldwide. It is a complex phenomenon, owing to the interaction of different factors, including biological, physiological, psychological, environmental, and social variables. Some groups, such as women and immigrants, are particularly vulnerable. However, little is known about how Chinese women in Italy live with and face chronic pain. The present study aimed at filling this knowledge gap by examining the burden of chronic pain in Chinese immigrants in Italy in terms of acculturation processes, perceived control over disease, social networks, and coping strategies. A qualitative approach was used, performing a thematic field analysis. We interviewed 82 Chinese women from different Italian towns (Genoa, Milan, Turin, Bologna, Florence, and Prato) in depth. The sense of belonging to the host culture was strong in our sample. However, this did not simply reflect or translate into a linear engagement with medical systems, as health care pathways were more complex and dual (both Chinese and Western). Chinese women who felt deeply rooted in the Italian environment did not discontinue the use of traditional Chinese medicine. Chronic pain extensively and adversely affected daily life, particularly interfering with work. Coping strategies were mainly adaptive behaviors, being problem focused or maladaptive, relying upon “cope and avoid” mechanisms. Chinese women preferred to use traditional Chinese remedies rather than conventional medicine, while using the Italian system in emergencies. Perceived control over chronic pain was usually external. Finally, Chinese women with chronic pain benefit from social networks and support, which were mainly composed of Chinese peers. In conclusion, our findings underline the tremendous burden of chronic pain affecting all aspects of Chinese women’s lives. Health care workers and providers should be aware of the complexity of chronic pain Therefore, a holistic approach, involving different stakeholders, should be adopted when managing chronic pain and approaching immigrant patients.

Accounting for Ethnicity-Related Differences in Ocular Surface Integrity as a Step Toward Understanding Contact Lens Discomfort

Contact lens discomfort is a common problem that can lead to unsuccessful or limited contact lens wear. Although many factors may contribute to contact lens discomfort, limited research has explored the influence of ethnicity-related differences in the anatomy and physiology of the ocular surface. Therefore, we performed a search of the literature in PubMed using key words related to "ocular surface" paired with the terms "race" and "ethnicity." The goal of this review was to determine potential areas of research regarding ethnicity differences, particularly between Asian and non-Asian eyes, in ocular surface integrity to advance our understanding of contact lens discomfort.

Understanding Ocular Discomfort and Dryness Using the Pain Sensitivity Questionnaire

PURPOSE

To utilize the Pain Sensitivity Questionnaire (PSQ) to assess the influence of pain sensitivity on perceptions of ocular discomfort and dryness.

METHODS

Subjects completed a battery of questionnaires, including history of ocular and general health, contact lens wear history, the Ocular Surface Disease Index (OSDI) questionnaire, visual analog scale (VAS) 100-point rating scales to assess severity and frequency of average and end of day (EOD) discomfort and dryness, and the PSQ to assess pain sensitivity level. Masked subjects were then instructed to wear one inverted and one normally oriented soft contact lens contralaterally for 30 minutes to induce an inter-eye difference in comfort and dryness sensations. Subjects rated comfort and dryness in each eye on VAS every 5 minutes during contact lens wear. A slit lamp examination was performed to evaluate ocular surface health and to assess contact lens fit.

RESULTS

One hundred and fifty-three subjects (111 females, 42 males) completed the study. In separate models, a higher PSQ score was significantly associated with higher OSDI score (p = 0.002), lower average and EOD comfort (p = 0.005 and 0.001, respectively), and greater EOD dryness (p = 0.04). The minimum (0.14) and maximum (7.14) PSQ scores observed in our subject cohort (i.e., from the subjects who were the least and most sensitive to pain, respectively) corresponded to an estimated difference of 11 points on the OSDI, 20 points on the VAS scale for average comfort, 31 points for EOD comfort and 17 points for EOD dryness. In a mixed effects model, a higher PSQ score was significantly associated with a greater inter-eye difference in comfort (p = 0.013) and dryness (p = 0.010) during CL wear.

CONCLUSIONS

Pain sensitivity influences perceptions of ocular discomfort and dryness, and should be taken into account when evaluating subjective assessments of these symptoms.

The Role of Language Use in Reports of Musculoskeletal Pain Among Hispanic and Non-Hispanic White Adolescents

OBJECTIVE

This study examined the role of English language use in the reported frequency of musculoskeletal pain among Hispanic and non-Hispanic White youth.

METHOD

This is a secondary data analysis using a cross-sectional sample of 12,189 Hispanic and non-Hispanic White adolescents recruited for the National Longitudinal Study of Adolescent to Adult Health. Respondents were classified into three groups: (a) English-speaking non-Hispanic Whites, (b) English-speaking Hispanics, and (c) Spanish-speaking Hispanics.

RESULTS

After controlling for body mass index and demographic, socioeconomic, and behavioral variables, Spanish-speaking Hispanics reported the least frequent musculoskeletal pain ( OR = 0.415, 95% CI [0.361, 0.477]; p < .001), followed by English-speaking Hispanics ( OR = 0.773, 95% CI [0.690, 0.865]; p < .001).

CONCLUSION

The experience of musculoskeletal pain is a physiological as well as a cultural phenomenon.

IMPLICATIONS FOR PRACTICE

Health care providers should consider the role of language use in reports of pain in Hispanic and non-Hispanic White adolescents.

Aldehyde dehydrogenase-2 regulates nociception in rodent models of acute inflammatory pain

Exogenous aldehydes can cause pain in animal models, suggesting that aldehyde dehydrogenase-2 (ALDH2), which metabolizes many aldehydes, may regulate nociception. To test this hypothesis, we generated a knock-in mouse with an inactivating point mutation in ALDH2 (ALDH2*2), which is also present in human ALDH2 of ~540 million East Asians. The ALDH2*1/*2 heterozygotic mice exhibited a larger response to painful stimuli than their wild-type littermates, and this heightened nociception was inhibited by an ALDH2-selective activator (Alda-1). No effect on inflammation per se was observed. Using a rat model, we then showed that nociception tightly correlated with ALDH activity (R(2) = 0.90) and that reduced nociception was associated with less early growth response protein 1 (EGR1) in the spinal cord and less reactive aldehyde accumulation at the insult site (including acetaldehyde and 4-hydroxynonenal). Further, acetaldehyde- and formalin-induced nociceptive behavior was greater in the ALDH2*1/*2 mice than in the wild-type mice. Finally, Alda-1 treatment was even beneficial when given after the inflammatory agent was administered. Our data in rodent models suggest that the mitochondrial enzyme ALDH2 regulates nociception and could serve as a molecular target for pain control, with ALDH2 activators, such as Alda-1, as potential non-narcotic, cardiac-safe analgesics. Furthermore, our results suggest a possible genetic basis for East Asians' apparent lower pain tolerance.

Physician consultation in young children with recurrent pain-a population-based study

Background. Recurrent pain is a common experience in childhood, but only few children with recurrent pain attend a physician. Previous studies yielded conflicting findings with regard to predictors of health care utilization in children with recurrent pain. Methods. The present study analyzes data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) study comprising n = 2,149 children (3-10 years old) with recurrent pain to find robust predictors. We used multiple logistic regressions to investigate age, gender, socio-economic status (SES), migration background, pain intensity, pain frequency, pain-related disability, mental health problems, and health-related quality of life (HRQL) as predictors for visiting a doctor due to pain. Results. Overall, young girls with high pain-related disability, intensity, frequency, and migration background were more likely to attend a physician. Pain-related disability had the largest impact. Socioeconomic status, health-related quality of life and mental health problems were not systematically related to health care utilization. An analysis of the variability of these results indicated that several hundred participants are needed until the results stabilize. Conclusions. Our findings highlight the importance of pain-related disability and frequency in assessing the severity of recurrent pain. Generic predictors and demographic variables are of lesser relevance to children with recurrent pain. On a methodological level, our results show that large-scale studies are need to reliably identify predictors of health care utilization.

Visual distraction alone for the improvement of colonoscopy-related pain and satisfaction

AIM: To evaluate the effect of a relaxing visual distraction alone on patient pain, anxiety, and satisfaction during colonoscopy.

METHODS: This study was designed as an endoscopist-blinded randomized controlled trial with 60 consecutively enrolled patients who underwent elective colonoscopy at Yokohama City University Hospital, Japan. Patients were randomly assigned to two groups: group 1 watched a silent movie using a head-mounted display, while group 2 only wore the display. All of the colonoscopies were performed without sedation. We examined pain, anxiety, and the satisfaction of patients before and after the procedure using questionnaires that included the Visual Analog Scale. Patients were also asked whether they would be willing to use the same method for a repeat procedure.

RESULTS: A total of 60 patients were allocated to two groups. Two patients assigned to group 1 and one patient assigned to group 2 were excluded after the randomization. Twenty-eight patients in group 1 and 29 patients in group 2 were entered into the final analysis. The groups were similar in terms of gender, age, history of prior colonoscopy, and pre-procedural anxiety score. The two groups were comparable in terms of the cecal insertion rate, the time to reach the cecum, the time needed for the total procedure, and vital signs. The median anxiety score during the colonoscopy did not differ significantly between the two groups (median scores, 20 vs 24). The median pain score during the procedure was lower in group 1, but the difference was not significant (median scores, 24.5 vs 42). The patients in group 1 reported significantly higher median post-procedural satisfaction levels, compared with the patients in group 2 (median scores, 89 vs 72, P = 0.04). Nearly three-quarters of the patients in group 1 wished to use the same method for repeat procedures, and the difference in rates between the two groups was statistically significant (75.0% vs 48.3%, P = 0.04). Patients with greater levels of anxiety before the procedure tended to feel a painful sensation. Among patients with a pre-procedural anxiety score of 50 or higher, the anxiety score during the procedure was significantly lower in the group that received the visual distraction (median scores, 20 vs 68, P = 0.05); the pain score during the colonoscopy was also lower (median scores, 23 vs 57, P = 0.04). No adverse effects arising from the visual distraction were recognized.

CONCLUSION: Visual distraction alone improves satisfaction in patients undergoing colonoscopy and decreases anxiety and pain during the procedure among patients with a high pre-procedural anxiety score.

Comparison of two hyaluronic acid formulations for safety and efficacy (CHASE) study in knee osteoarthritis: a multicenter, randomized, double-blind, 26-week non-inferiority trial comparing Durolane to Artz

INTRODUCTION

Intra-articular injection of hyaluronic acid (HA) is often used as therapy for knee osteoarthritis because it is less expensive and less aggressive than total knee replacement. Therefore, it is important to document whether HA is safe and efficacious. We tested whether single and multiple injection viscosupplementation with HA is associated with clinically meaningful pain relief in a new randomized clinical trial (RCT). Our objective was to compare safety and efficacy of intra-articular HA in two formulations: one 3.0 ml injection of Durolane versus five 2.5 ml injections of Artz for the treatment of knee osteoarthritis pain.

METHODS

Patients (N=349) from the People's Republic of China were randomized to treatment (Durolane=175, Artz=174). The Durolane group received a 3.0 ml injection at week 0 (baseline), with sham skin punctures at weeks 1, 2, 3, and 4. The Artz group received one 2.5 ml injection at each of the same time points. The primary assessment tool was the Likert-type Western Ontario and McMaster University (WOMAC) pain scale at weeks 0, 6, 10, 14, 18, and 26. Secondary assessments were WOMAC physical function, knee stiffness, and global self-assessment, at identical time points. Statistically-controlled analyses were non-inferiority of Durolane over 18, then over 26 weeks, with a priori non-inferiority defined as 8% of the relevant scale. Acetaminophen was permitted as rescue analgesia and all adverse events (AEs) were recorded.

RESULTS

Overall study retention was excellent; 332 patients (95.1%) completed 18 weeks and 319 (91.4%) completed 26 weeks, with no significant retention difference between treatment arms. All variables met non-inferiority criteria over 18 and 26 weeks. Efficacy response in both arms was >90%. Treatment-related AEs were 9.8% (17/174) for Artz and 13.1% (23/175) for Durolane.

CONCLUSIONS

A single injection of Durolane is non-inferior to 5 injections of Artz over 18 and 26 weeks for pain, physical function, global self-assessment, and knee stiffness. Both treatments were efficacious, safe, and well tolerated.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01295580 . Registered 11 February 2011.

On the importance of being vocal: saying "ow" improves pain tolerance

Vocalizing is a ubiquitous pain behavior. The present study investigated whether it helps alleviate pain and sought to discern potential underlying mechanisms. Participants were asked to immerse one hand in painfully cold water. On separate trials, they said "ow," heard a recording of them saying "ow," heard a recording of another person saying "ow," pressed a button, or sat passively. Compared to sitting passively, saying "ow" increased the duration of hand immersion. Although on average, participants predicted this effect, their expectations were uncorrelated with pain tolerance. Like vocalizing, button pressing increased the duration of hand immersion, and this increase was positively correlated with the vocalizing effect. Hearing one's own or another person's "ow" was not analgesic. Together, these results provide first evidence that vocalizing helps individuals cope with pain. Moreover, they suggest that motor more than other processes contribute to this effect.

PERSPECTIVE

Participants immersed their hand in painfully cold water longer when saying "ow" than when doing nothing. Whereas button pressing had a similar effect, hearing one's own or another person's "ow" did not. Thus, vocalizing in pain is not only communicative. Like other behaviors, it helps cope with pain.

Targeting aldehyde dehydrogenase 2: new therapeutic opportunities

A family of detoxifying enzymes called aldehyde dehydrogenases (ALDHs) has been a subject of recent interest, as its role in detoxifying aldehydes that accumulate through metabolism and to which we are exposed from the environment has been elucidated. Although the human genome has 19 ALDH genes, one ALDH emerges as a particularly important enzyme in a variety of human pathologies. This ALDH, ALDH2, is located in the mitochondrial matrix with much known about its role in ethanol metabolism. Less known is a new body of research to be discussed in this review, suggesting that ALDH2 dysfunction may contribute to a variety of human diseases including cardiovascular diseases, diabetes, neurodegenerative diseases, stroke, and cancer. Recent studies suggest that ALDH2 dysfunction is also associated with Fanconi anemia, pain, osteoporosis, and the process of aging. Furthermore, an ALDH2 inactivating mutation (termed ALDH2*2) is the most common single point mutation in humans, and epidemiological studies suggest a correlation between this inactivating mutation and increased propensity for common human pathologies. These data together with studies in animal models and the use of new pharmacological tools that activate ALDH2 depict a new picture related to ALDH2 as a critical health-promoting enzyme.