Age, Race, Ethnicity, and Sex of Participants in Clinical Trials Focused on Chronic Pain

There is limited data on equitable inclusion in chronic pain trials. We aimed to 1) identify the frequency of reporting age, race, ethnicity, and sex in clinical trials targeting chronic pain, and 2) compare sociodemographic representation to the United States (US) population. We examined US-based intervention trials for chronic pain initiated between 2007 and 2021 and registered on ClinicalTrials.gov. We 1) assessed the frequency of reporting each demographic variable, 2) compared representation with US population estimates, and 3) explored change in reporting over time. Of 501 clinical trials, the frequency of reporting was as follows: 36.9% reported older adults, 54.3% reported race, 37.4% reported ethnicity, and 100% reported sex. Rates of race and ethnicity reporting increased, but older adult age reporting decreased over time (ps < .00001). Compared to 2020 US population estimates, there was an equitable representation of older adults, under-representation of individuals identifying as American Indian or Alaska Native (.8% vs .6%), Asian (5.6% vs 2.9%), Black or African American (12.6% vs 12.2%), with more than one race (2.9% vs 1.2%), and Hispanic/Latino (16.9% vs 14.1%). There was an over-representation of individuals identifying as Native Hawaiian or Pacific Islander (.2% vs .5%) or White (70.4% vs 72.9%), and of females (50.8% vs 68.4%). Some representation rates varied by chronic pain condition. Reporting of older adult age, race, and ethnicity was low in chronic pain trials in ClinicalTrials.gov, reinforcing the need for adhering to reporting guidelines. Representation varied across trials compared with US population data, particularly among those identifying as Hispanic/Latino and certain minority racial groups. PERSPECTIVE: Despite initiatives to increase the reporting of demographic information, doing so in clinical pain trials is far from ubiquitous. Moreover, efforts to improve diversity in these trials continue to be insufficient. Indeed, Black, Indigenous, and People of Color (BIPOC) remain under-represented in clinical pain trials.

Race-specific associations: inflammatory mediators and chronic low back pain

ABSTRACT

Chronic low back pain (cLBP) is a global health crisis that disproportionately burdens non-Hispanic Black (NHB) individuals, compared with those who identify as non-Hispanic White (NHW). Despite the growing personal and societal impact of cLBP, its biological underpinnings remain poorly understood. To elucidate the biological factors that underlie the racial disparities in cLBP, this study sought to determine whether inflammatory mediators associated with pain interference (PI), pain at rest (PAR), and movement-evoked pain (MEP) differ as a function of racial identity. Blood samples were collected from 156 individuals with cLBP (n = 98 NHB participants, n = 58 NHW participants). Enzyme-linked immunosorbent assay and multiplex assays were used to quantify concentrations of proinflammatory (fibrinogen, C-reactive protein [CRP], serum amyloid A, tumor necrosis factor α [TNF-α], and interleukin [IL]-1α, IL-1β, and IL-6) and anti-inflammatory markers (IL-4 and IL-13). Spearman rho correlations were used to assess associations among markers of inflammation and PI, PAR, and MEP using the Brief Pain Inventory-Short Form. Analyses revealed that for NHW patients, CRP, serum amyloid A, and IL-6 were positively associated with cLBP outcomes and IL-4 was inversely associated with PAR and MEP. However, for NHB patients, only IL-1α was positively associated with PAR. Our findings suggest that, while there are associations between inflammation and cLBP outcomes, the biomarkers that underlie the inflammation could very well differ as a function of racialized minority group. However, more research with racially inclusive samples is needed to elucidate the mechanisms that may contribute to racial disparities in cLBP.

Quantitative somatosensory testing of the abdomen: establishing initial reference values across developmental age and biological sex

ABSTRACT

Abdominal pain is a common symptom of several debilitating conditions (eg, inflammatory bowel disease, irritable bowel syndrome, and endometriosis) and affects individuals throughout their lifespan. Quantitative sensory testing (QST) reference values exist for many body sites but not the abdomen. Using a QST battery adapted from the German Research Network on Neuropathic Pain, we collected QST data on the upper and lower abdomen in 181 pain-free participants, ages 12 to 50 years, to establish reference values by age and biological sex. The normative values are presented as medians for each QST measure by sex (male, n = 63; female, n = 118) and across 3 age categories (adolescents: 12-19 years, n = 48; young adults: 20-30 years, n = 87; and adults: 31-50 years, n = 46). Evaluating the sensory functioning of the abdomen and characterizing ranges of QST measures is an essential first step in understanding and monitoring the clinical course of sensory abnormalities in patients with underlying diseases affecting the abdomen and pelvis. The impact of age and development on sensory functioning is necessary, given age-related changes in pain perception and modulation.

The role of sleep disturbance in reduced accuracy on a divided attention task among patients with fibromyalgia

Introduction

Patients with fibromyalgia show impaired cognitive performance compared with healthy, pain-free controls. Sleep disturbance, anxiety, and depression are highly prevalent among patients with fibromyalgia, and each is associated with impaired cognitive performance. Yet, limited work has explored whether psychosocial factors contribute to group differences in cognitive performance.

Objectives

This secondary data analysis investigated differences in cognitive performance between patients with fibromyalgia and healthy controls, and whether psychosocial factors accounted for these differences.

Methods

Adults with fibromyalgia (N = 24) and healthy, pain-free controls (N = 26) completed 2 cognitive tasks and the Patient-Reported Outcomes Measurement Information System sleep disturbance, anxiety, and depression short forms. Independent samples t tests were used to test for differences in cognitive performance between patients with fibromyalgia and healthy controls. Pearson correlations were conducted to examine associations between psychosocial factors and cognitive performance. Psychosocial factors significantly related to cognitive performance were explored as potential mediators of group differences in cognitive performance.

Results

Patients with fibromyalgia demonstrated poorer accuracy for divided attention compared with healthy controls, and sleep disturbance mediated this group difference. On the attentional switching task, healthy controls showed a greater switch-cost for accuracy compared with patients with fibromyalgia, but there was no group difference in reaction time. Anxiety and depression were not related to cognitive performance.

Conclusion

We found that patients with fibromyalgia reported greater sleep disturbance and, in turn, had poorer accuracy on the divided attention task. Sleep disturbance is modifiable with behavioral interventions, such as cognitive behavioral therapy, and may be a target for improving sleep quality and cognitive performance among patients with fibromyalgia.

Perioperative insomnia trajectories and functional outcomes after total knee arthroplasty

ABSTRACT

Longitudinal total knee arthroplasty (TKA) studies indicate that a substantial percentage of patients continue to experience clinically significant pain and functional impairment after surgery. Insomnia has been associated with poorer surgical outcomes; however, previous work has largely focused on long-term postsurgical insomnia. This study builds on previous work by examining sleep and pain outcomes about perioperative insomnia trajectories. Insomnia symptoms (using the Insomnia Severity Index) during the acute perioperative period (2 weeks pre-TKA to 6 weeks post-TKA) were used to classify participants into perioperative insomnia trajectories: (1) No Insomnia (ISI < 8), (2) New Insomnia (baseline < 8; postoperative ≥ 8 or ≥6-point increase), (3) Improved Insomnia (baseline ≥ 8, postoperative < 8 or ≥6-point decrease), and (4) Persistent Insomnia (ISI ≥ 8). Insomnia, pain, and physical functioning were assessed in participants with knee osteoarthritis (n = 173; M age = 65 ± 8.3, 57.8% female) at 5 time points: 2 weeks pre-TKA, post-TKA: 6 weeks, 3 months, 6 months, and 12 months. Significant main effects were seen for insomnia trajectory and time, and trajectory-by-time interactions for postoperative insomnia, pain severity, and physical functioning ( P' s < 0.05). The Persistent Insomnia trajectory had the worst postoperative pain at all follow-ups and marked insomnia and physical functioning impairment post-TKA ( P' s < 0.05). The New Insomnia trajectory had notable long-term insomnia (6 weeks to 6 months) and acute (6 weeks) postoperative pain and physical functioning ( P' s < 0.05). Findings indicated a significant relationship between perioperative insomnia trajectory and postoperative outcomes. Results of this study suggest that targeting presurgical insomnia and preventing the development of acute postoperative insomnia may improve long-term postoperative outcomes, with an emphasis on persistent perioperative insomnia due to poorer associated outcomes.

The mediating effect of social functioning on the relationship between catastrophizing and pain among patients with chronic low back pain

OBJECTIVE

Pain catastrophizing can be characterized as an interpersonal form of coping used to elicit support or empathy from others. Despite intentions of increasing support, catastrophizing can impair social functioning. While considerable work has addressed the relationship between catastrophizing and pain, limited empirical work has examined this relationship within a social context. First, we examined the role of catastrophizing as a potential contributor to group differences (chronic low back pain [cLBP] vs pain-free controls) in social functioning. Then we conducted a follow-up, exploratory analysis to examine the relationships between catastrophizing, social functioning, and pain within the subgroup of participants with cLBP.

METHODS

In this observational study, participants with cLBP (N = 62) and pain-free controls (N = 79) completed validated measures of pain, social functioning, and pain catastrophizing. A mediation analysis was conducted to examine whether catastrophizing mediated group differences (cLBP vs controls) in social functioning. A follow-up, exploratory mediation analysis then tested whether social functioning mediated the association between catastrophizing and pain within the subgroup of cLBP participants.

RESULTS

Participants with cLBP reported higher levels of pain, impaired social functioning, and higher catastrophizing compared to pain-free controls. Catastrophizing partially mediated the group difference in impaired social functioning. Additionally, social functioning mediated the association between higher catastrophizing and greater pain within the subgroup of cLBP participants.

CONCLUSIONS

We showed that impaired social functioning was driving the relationship between higher pain catastrophizing and worse pain among participants with cLBP. Interventions, such as cognitive behavioral therapy, should address catastrophizing in individuals with cLBP, while simultaneously improving social functioning.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing

Background and Objectives

Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes.

Research Design and Methods

This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery.

Results

Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months.

Discussion and Implications

Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

Brief Mindfulness-Based Cognitive Behavioral Therapy is Associated with Faster Recovery in Patients Undergoing Total Knee Arthroplasty: A Pilot Clinical Trial

OBJECTIVE

To assess whether brief mindfulness-based cognitive behavioral therapy (MBCBT) could enhance the benefits of total knee arthroplasty (TKA) in improving pain and pain-related disability. Specifically, to determine 1) whether patients who received MBCBT differed from matched controls who received treatment-as-usual with regard to postsurgical pain outcomes and 2) whether changes in pain catastrophizing, depression, or anxiety explained the potential effects of MBCBT on pain outcomes.

DESIGN

Pilot clinical trial.

SETTING

An academic teaching hospital serving a large urban and suburban catchment area surrounding the Boston, Massachusetts metropolitan region.

SUBJECTS

Sample of 44 patients undergoing TKA. Patients who completed a brief MBCBT intervention (n = 22) were compared with age-, race-, and sex-matched controls who received treatment-as-usual (n = 22).

METHODS

The MBCBT intervention included four 60-minute sessions delivered by a pain psychologist in person and via telephone during the perioperative period. Participants were assessed at baseline and at 6 weeks, 3 months, and 6 months after surgery.

RESULTS

Compared with matched controls, patients who received MBCBT had lower pain severity and pain interference at 6 weeks after surgery. Group differences in outcomes were mediated by changes in pain catastrophizing but not by changes in depression or anxiety. The MBCBT group had similar reductions in pain severity and interference as the control group did at 3 and 6 months after surgery.

CONCLUSIONS

This work offers evidence for a safe and flexibly delivered nonpharmacological treatment (MBCBT) to promote faster recovery from TKA and identifies change in pain catastrophizing as a mechanism by which this intervention could lead to enhanced pain-related outcomes.

Let’s Get Physical! A Comprehensive Review of Pre- and Post-Surgical Interventions Targeting Physical Activity to Improve Pain and Functional Outcomes in Spine Surgery Patients

The goal of this comprehensive review was to synthesize the recent literature on the efficacy of perioperative interventions targeting physical activity to improve pain and functional outcomes in spine surgery patients. Overall, research in this area does not yet permit definitive conclusions. Some evidence suggests that post-surgical interventions may yield more robust long-term outcomes than preoperative interventions, including large effect sizes for disability reduction, although there are no studies directly comparing these surgical approaches. Integrated treatment approaches that include psychosocial intervention components may supplement exercise programs by addressing fear avoidance behaviors that interfere with engagement in activity, thereby maximizing the short- and long-term benefits of exercise. Efforts should be made to test brief, efficient programs that maximize accessibility for surgical patients. Future work in this area should include both subjective and objective indices of physical activity as well as investigating both acute postoperative outcomes and long-term outcomes.

A Brief Overview: Sex Differences in Prevalent Chronic Musculoskeletal Conditions

Musculoskeletal (MSK) pain disorders are some of the most prevalent and disabling chronic pain conditions worldwide. These chronic conditions have a considerable impact on the quality of life of individuals, families, communities, and healthcare systems. Unfortunately, the burden of MSK pain disorders does not fall equally across the sexes. Females consistently demonstrate more prevalent and severe clinical presentations of MSK disorders, and this disparity increases in magnitude with age. The aim of the present article is to review recent studies that have examined sex differences between males and females in four of the most common MSK pain disorders: neck pain, low back pain, osteoarthritis, and rheumatoid arthritis.

The Pain and PRAYER Scale (PPRAYERS): development and validation of a scale to measure pain-related prayer

OBJECTIVES

Prayer is a devotional practice used across religious traditions to commune with the sacred and has been used as a coping strategy for pain. Previous research on prayer as a pain-coping strategy has mixed results with prayer associated with both greater and lesser pain depending on prayer type. To date there is only one measure of pain-related prayer, the prayer subscale of the Coping Strategies Questionnaire-Revised which solely measures passive prayer, neglecting other types of prayer (e.g., active and neutral). To better understand the relationship between pain and prayer a comprehensive measure of prayer for pain is needed. The aim of this study was to develop and validate the Pain-related PRAYER Scale (PPRAYERS), a questionnaire exploring active, passive, and neutral petitionary prayers to God or a Higher Power in response to pain.

METHODS

Adults with chronic pain (N = 411) completed demographic, health, and pain-related questionnaires including PPRAYERS.

RESULTS

Results of an exploratory factor analysis yielded a three-factor structure consistent with active, passive, and neutral subscales. A confirmatory factor analysis resulted in adequate fit following the removal of five items. PPRAYERS showed good internal consistency as well as convergent and discriminant validity.

DISCUSSION

These results provide preliminary validation for PPRAYERS, a novel measure for pain-related prayer.

The Relationship of Postoperative Pain and Opioid Consumption to Postoperative Delirium After Spine Surgery

Purpose

To examine the relationship between postoperative pain and opioid use and the development of postoperative delirium (POD), with attention to the preoperative opioid use status of patients.

Methods

This was a secondary analysis of data from a prospective observational study of patients (N = 219; ≥70 years old) scheduled to undergo elective spine surgery. Maximal daily pain scores (0-10) and postoperative morphine milligram equivalents per hour (MME/hr) were determined for postoperative days 1-3 (D1-3). POD was assessed by daily in-person interviews using the Confusion Assessment Method and chart review.

Results

Patients who reported regular preoperative opioid use (n = 58, 27%) reported significantly greater maximal daily pain scores, despite also requiring greater daily opioids (MME/hr) in the first 3 days after surgery. These patients were also more likely to develop POD. Interestingly, while postoperative pain scores were significantly higher in patients who developed POD, postoperative opioid consumption was not significantly higher in this group.

Conclusion

POD was associated with greater postoperative pain, but not with postoperative opioid consumption. While postoperative opioid consumption is often blamed for delirium, these findings suggest that uncontrolled pain may actually be a more important factor, particularly among patients who are opioid tolerant. These findings underscore the importance of employing multimodal perioperative analgesic management, especially among older patients who have a predilection to developing POD and baseline tolerance to opioids.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Loneliness and Pain Catastrophizing Among Individuals with Chronic Pain: The Mediating Role of Depression

Purpose

Loneliness increased during the COVID-19 pandemic and social distancing guidelines, potentially exacerbating negative cognitions about pain. The present study investigated the longitudinal relationship between loneliness, assessed during the early weeks of the pandemic, and pain catastrophizing, assessed after living in the pandemic for approximately 1 year, among chronic pain patients. We also examined whether severity of depressive symptoms mediated this association.

Methods

This prospective longitudinal study recruited individuals with chronic pain (N=93) from Massachusetts using an online convenience sampling method via the platform Rally. Participants completed an initial survey early after the onset of social distancing (4/28/20–6/17/20; Time 1) and a follow-up survey 1 year later (5/21/21–6/7/21; Time 2). Participants completed validated assessments of loneliness (T1), pain catastrophizing (T2), and depression (T2). Spearman correlations and Mann–Whitney U-tests were used to explore associations among psychosocial, pain, and participant characteristics. A mediation analysis was conducted to test whether the association between loneliness and pain catastrophizing was mediated by depression.

Results

Participants had a mean age of 40.6 years and were majority female (80%) and White (82%). Greater loneliness was associated with subsequent higher pain catastrophizing (b=1.23, 95% CI [0.03, 2.44]). Mediation analysis showed a significant indirect effect (b=0.57, 95% CI [0.10, 1.18) of loneliness (T1) on catastrophizing (T2) through depression (T2) while accounting for several important covariates. The direct effect of loneliness on catastrophizing was no longer significant when depression was included in the model (b=0.66, 95% CI [−0.54, 1.87]).

Conclusion

Findings suggest that greater loneliness during the pandemic was associated with higher pain catastrophizing 1 year later, and severity of depression after living in the pandemic mediated this association. As loneliness, depression, and catastrophizing can all be modified with behavioral interventions, understanding the temporal associations among these variables is important for the employment of future empirically supported treatments.

Introversion, Extraversion, and Worsening of Chronic Pain Impact during Social Isolation: A Mediation Analysis

COVID-19 social distancing mandates increased social isolation, resulting in changes in pain severity and interference among individuals with chronic pain. Differences in personality (e.g., introversion/extraversion) may modulate responses to social isolation. We examined the influence of introversion on reported social distancing-related increases in pain interference and assessed for mediators of this relationship. Individuals with chronic pain (n = 150) completed validated questionnaires 4–8 weeks after implementation of social distancing mandates. Introversion/extraversion was measured using a subscale of the Myers-Briggs Type Indicator and changes in pain and psychosocial variables were calculated by comparing participants’ recalled and current scores. Association between introversion/extraversion and other variables were assessed using linear regression. A parallel mediation was used to examine mediators of the association between introversion and change in pain interference. Higher introversion was associated with a decrease in pain interference after social distancing (Rho = − .194, p = .017). Parallel mediation analysis revealed that the relationship between introversion/extraversion and change in pain interference was mediated by changes in sleep disturbance and depression, such that higher introversion was associated with less isolation-induced sleep disruption and depression, and thereby less worsening of pain interference. These findings suggest that personality factors such as introversion/extraversion should be considered when personalizing treatment of chronic pain.

The Effects of Combined Respiratory-Gated Auricular Vagal Afferent Nerve Stimulation and Mindfulness Meditation for Chronic Low Back Pain: A Pilot Study

OBJECTIVE

Respiratory-gated Auricular Vagal Afferent Nerve stimulation (RAVANS) is a safe nonpharmacological approach to managing chronic pain. The purpose of the current study was to examine (1) the feasibility and acceptability of RAVANS, combined with mindful meditation (MM) for chronic low back pain (CLBP), (2) the potential synergy of MM+RAVANS on improving pain, and (3) possible moderators of the influence of MM+RAVANS on pain.

DESIGN

Pilot feasibility and acceptability study.

SETTING

Pain management center at large academic medical center.

SUBJECTS

Nineteen adults with CLBP and previous MM training.

METHODS

Participants attended two sessions during which they completed quantitative sensory testing (QST), rated pain severity, and completed a MM+stimulation session. Participants received RAVANS during one visit and sham stimulation during the other, randomized in order. Following intervention, participants repeated QST.

RESULTS

MM+RAVANS was well tolerated, acceptable, and feasible to provide relief for CLBP. Both MM+stimulation sessions resulted in improved back pain severity, punctate pain ratings, and pressure pain threshold. Individuals with greater negative affect showed greater back pain improvement from MM+RAVANS while those with greater mindfulness showed greater back pain improvement from MM+sham.

CONCLUSIONS

Results suggest that for CLBP patients with prior MM training, the analgesic effects of MM may have overshadowed effects of RAVANS given the brief single session MM+RAVANS intervention. However, those with greater negative affect may benefit from combined MM+RAVANS.

Making Pain Research More Inclusive: Why and How

Current knowledge about mechanisms and interventions for pain has largely been derived from samples that are healthier, wealthier, younger, and more likely to be White than the general population. Failure to conduct inclusive pain research not only restricts generalizability and application of findings, but also hampers the discovery of mechanisms and the development of measures and interventions that are valid across population subgroups. Most of all, inclusive practices are critical to ensure that underrepresented groups derive equitable benefit from pain research. Here, we provide guidance for the pain research community on how to adopt inclusive research practices. We define "inclusion" to encompass a range of identities and characteristics, including racialized group/ethnicity, disability status, gender identity, sexual orientation, and age. We first describe principles relevant to promoting inclusion in pain research, including attention to: 1) stakeholder engagement; 2) structural factors underlying inequities; 3) the limitations of "disparity" research; 4) intersectionality; and 5) universal design. Next, we provide checklists with practical strategies for making studies more inclusive at each stage of the research process. We conclude by calling for system-level changes to ensure that the future of pain research is socially just, scientifically productive, and responsive to the needs of all people. PERSPECTIVE: This paper offers guidance on promoting inclusion of underrepresented groups in pain research. We describe principles relevant to conducting more inclusive research; eg, attention to stakeholder engagement, structural factors, and universal design. We provide checklists with practical strategies for inclusion at each stage of the research process.

Social support and psychological distress among chronic pain patients: The mediating role of mindfulness

Although an inverse relation between social support and psychological distress among chronic pain patients has been previously reported, little is known about what mediates this association. We examined mindfulness as a mediator of the relationship between social support and psychological distress. In this cross-sectional study, chronic pain patients (N=94) completed assessments of social support, mindfulness, and psychological distress. Greater social support was associated with less psychological distress. Greater mindfulness was associated with greater social support and less psychological distress. Mediation analyses demonstrated that mindfulness partially mediated the relationship between social support and psychological distress. Findings support and extend prior research by demonstrating a potentially important mediating effect of mindfulness within chronic pain patients. This suggests an important link between social support and mindfulness, and that their integration in the pursuit of mental health should be considered in future behavioral interventions.

Characterizing the Use of Expectations in Orthopedic Surgery Research: A Scoping Review

Objective

Orthopedic literature on expectations is limited by lack of uniformity in how expectations are defined, conceptualized, and measured. Within this scoping review, we present a conceptual framework for understanding the construct of expectations and its derivatives (ie, expectation, expectancy, expectancies, etc) in studies of elective surgical orthopedic procedures. We also utilize this framework to map the current orthopedic surgery literature on expectations, highlighting its strengths, weaknesses, and gaps in its knowledge base.

Methods

We included articles that mentioned both expectations and one or more of 10 selected surgeries in their title or abstract. We focused on representative elective orthopedic surgeries that covered the body's major regions. We operationalized each study's individual expectation items into one of the expectation concept types within the presented conceptual model. We also extracted the name and type of expectations measurement tool used, whose expectations were measured, and descriptive information (eg, surgery type, publication date, country of origin, and study type).

Results

Ninety studies were included, with 70% published after 2008. A total of 64% investigated total knee and total hip arthroplasty, whereas 90% of studies investigated the expectations of patients, 5.6% investigated the expectations of physicians, and 4.4% investigated both. Of all studies, 72% utilized either study‐specific instruments with close‐ended, Likert‐type response formats or modifications of existing expectations questionnaires. Most studies focused on desirable, nontimeline‐related, treatment outcome expectations. Many studies aggregated multiple expectation results into a single score.

Conclusion

Adopting the standardized framework for expectations presented in this study will foster clearer communication and permit researchers to aggregate results across studies.

An experimental investigation of the relationships among race, prayer, and pain

Background and aims Compared to White individuals, Black individuals demonstrate a lower pain tolerance. Research suggests that differences in pain coping strategies, such as prayer, may mediate this race difference. However, previous research has been cross-sectional and has not determined whether prayer in and of itself or rather the passive nature of prayer is driving the effects on pain tolerance. The aim of this study was to clarify the relationships among race, prayer (both active and passive), and pain tolerance. Methods We randomly assigned 208 pain-free participants (47% Black, 53% White) to one of three groups: active prayer ("God, help me endure the pain"), passive prayer ("God, take the pain away"), or no prayer ("The sky is blue"). Participants first completed a series of questionnaires including the Duke University Religion Index, the Coping Strategies Questionnaire-Revised (CSQ-R), and the Pain Catastrophizing Scale. Participants were then instructed to repeat a specified prayer or distractor coping statement while undergoing a cold pressor task. Cold pain tolerance was measured by the number of seconds that had elapsed while the participant's hand remained in the cold water bath (maximum 180 s). Results Results of independent samples t-tests indicated that Black participants scored higher on the CSQ-R prayer/hoping subscale. However, there were no race differences among other coping strategies, religiosity, or catastrophizing. Results of a 2 (Race: White vs. Black)×3 (Prayer: active vs. passive vs. no prayer) ANCOVA controlling for a general tendency to pray and catastrophizing in response to prayer indicated a main effect of prayer that approached significance (p=0.06). Pairwise comparisons indicated that those in the active prayer condition demonstrated greater pain tolerance than those in the passive (p=0.06) and no prayer (p=0.03) conditions. Those in the passive and no prayer distractor conditions did not significantly differ (p=0.70). There was also a trending main effect of race [p=0.08], with White participants demonstrating greater pain tolerance than Black participants. Conclusions Taken together, these results indicate that Black participants demonstrated a lower pain tolerance than White participants, and those in the active prayer condition demonstrated greater tolerance than those in the passive and no prayer conditions. Furthermore, Black participants in the passive prayer group demonstrated the lowest pain tolerance, while White participants in the active prayer group exhibited the greatest tolerance. Results of this study suggest that passive prayer, like other passive coping strategies, may be related to lower pain tolerance and thus poorer pain outcomes, perhaps especially for Black individuals. On the other hand, results suggest active prayer is associated with greater pain tolerance, especially for White individuals. Implications These results suggest that understanding the influence of prayer on pain may require differentiation between active versus passive prayer strategies. Like other active coping strategies for pain, active prayer may facilitate self-management of pain and thus enhance pain outcomes independent of race. Psychosocial interventions may help religiously-oriented individuals, regardless of race, cultivate a more active style of prayer to improve their quality of life.

Racial and ethnic differences in the experience and treatment of noncancer pain

The burden of pain is unequal across racial and ethnic groups. In addition to racial and ethnic differences in the experience of pain, there are racial and ethnic disparities in the assessment and treatment of pain. In this article, we provide a nonexhaustive review of the biopsychosocial mechanistic factors contributing to racial and ethnic differences in both the experience and treatment of pain. Using a modified version of the Socioecological Model, we focus on patient-, provider- and system-level factors including coping, perceived bias and discrimination, patient preferences, expectations, patient/provider communication, treatment outcomes and healthcare access. In conclusion, we provide psychosocial factors influencing racial and ethnic differences in pain and highlight future research targets and possible solutions to reduce these disparities.

Race Differences in Physical Activity Uptake Within a Workplace Wellness Program: A Comparison of Black and White Employees

PURPOSE

To examine differences in physical activity (PA) uptake between black and white employees during a financial incentive-based workplace intervention.

DESIGN

Prospective cohort study from July 2014 to June 2015 (NCT02850094).

SETTING

Tertiary academic medical center.

PARTICIPANTS

Forty-three black and 182 white nonclinical employees.

INTERVENTION

Participants self-selected or were assigned to teams. Participants completed a 24-week intervention receiving rewards for meeting weekly PA goals (increasing moderate-to-vigorous PA [MVPA] by 10% from previous week or meeting Guidelines threshold of 150 minutes of MVPA).

MEASURES

Outcomes included weekly MVPA in minutes, average daily step counts, number of weeks meeting personal goals and the Guidelines, and Fitbit adherence in days and weeks.

ANALYSIS

We performed an analysis of covariance for each outcome, with race as the primary independent variable of interest, adjusting for demographic and health-related covariates.

RESULTS

During the intervention, blacks walked 9128 steps per day while whites walked 7826 steps per day, a difference of approximately 1300 steps (P < .05). Blacks also demonstrated a greater uptake in both steps and MVPA from baseline than did whites, resulting in similar MVPA throughout the intervention.

CONCLUSIONS

Findings suggest that workplace PA interventions using financial incentives may result in similar engagement in MVPA among white and black employees, while black employees walk more steps during the intervention. Limitations include a primarily white female sample which may not generalize.

What do you expect? Catastrophizing mediates associations between expectancies and pain-facilitatory processes

BACKGROUND

Pain expectancies are associated with altered pain sensitivity in individuals with chronic pain. However, little is known about the processes by which pain expectancies impact pain processing. This study assessed the association between pain expectancies and temporal summation (TS) of pain, and examined whether pain catastrophizing mediated this association.

METHODS

In this cross-sectional study, participants (437 chronic low back pain [CLBP] patients, 115 controls) completed self-report measures of pain intensity, pain expectancies and pain catastrophizing before undergoing psychophysical pain-testing procedures designed to assess mechanical TS of mechanical pain. Pearson's correlations examined the associations between study variables in CLBP patients and controls. Bootstrapping mediation analyses assessed the mediating role of pain catastrophizing on the association between pain expectancies and TS of pain.

RESULTS

Temporal summation of pain was significantly associated with pain expectancies (r = 0.113) and pain catastrophizing (r = 0.171) in CLBP patients. Results of mediation analyses revealed that pain catastrophizing mediated the relationship between pain expectancies and TS of pain in CLBP patients (ab = 0.309, 95% CI = 0.1222-0.5604), but not in healthy controls (ab = -0.125, 95% CI = -0.5864 to 0.0244).

CONCLUSIONS

The findings from this study suggest that compared to controls, CLBP patients show increased sensitivity to mechanical pain procedures and enhanced pain-facilitatory processing, proving further evidence for changes in central nervous system pain processing in CLBP patients. Our results also suggest that pain catastrophizing may be the mechanism by which pain expectancies are associated with TS of pain in CLBP patients.

SIGNIFICANCE

Individuals with chronic low back pain who expect higher levels of pain and catastrophize about their pain are more likely to experience altered pain sensitivity. Our results point to catastrophizing as a mechanism of action through which psychological factors may operate and lead to the development and maintenance of chronic low back pain.

Social Influences on Peer Judgments about Chronic Pain and Disability

Chronic pain is a leading cause of work absenteeism and disability compensation. Previous work demonstrates that patients with chronic illness often seek advice, such as whether or not to pursue disability benefits, from peers with similar health conditions. The current study examined the extent that social factors influence patients with chronic pain ("peers") when making disability judgments and recommendations for other patients with chronic pain. Participants (N = 71) made pain-related and disability ratings for fictional vignette patients that varied in weight (normal vs obese), fault of accident, and physical work demands. Results of repeated measures analyses of variance indicated that participants rated patients with obesity, who were not at fault, and who held a physically demanding job as experiencing more severe pain symptoms and disability and were more likely to recommend they seek disability benefits. Participants who had applied for disability benefits themselves rated patients as more disabled than participants who had not applied for disability. These data suggest that patients with chronic pain are influenced by patient and contextual factors when making pain-related and disability judgments for peers. These judgments may impact patient decision making via peer support programs and online forums. PERSPECTIVE: This study suggests that patients with chronic pain are influenced by patient weight, fault of accident, and physical work demands when making judgments about pain and disability for peers. Future studies should examine the extent such peer-to-peer recommendations influence actual disability-seeking behaviors for pain.

Evaluating psychosocial contributions to chronic pain outcomes

The biopsychosocial model of pain dominates the scientific community's understanding of chronic pain. Indeed, the biopsychosocial approach describes pain and disability as a multidimensional, dynamic integration among physiological, psychological, and social factors that reciprocally influence one another. In this article, we review two categories of studies that evaluate the contributions of psychosocial factors to the experience of chronic pain. First, we consider general psychosocial variables including distress, trauma, and interpersonal factors. Additionally, we discuss pain-specific psychosocial variables including catastrophizing, expectations, and pain-related coping. Together, we present a diverse array of psychological, social, and contextual factors and highlight the need to consider their roles in the development, maintenance, and treatment of chronic pain conditions.

Loneliness Mediates the Relationship Between Pain During Intercourse and Depressive Symptoms Among Young Women

Previous research suggests that women who experience pain during intercourse also experience higher rates of depressive symptoms. Loneliness might be one factor that contributes to this relationship. We hypothesized that women who experience more severe and interfering pain during intercourse would report higher rates of loneliness and higher rates of depressive symptoms. Further, we hypothesized that loneliness would mediate the relationship between pain during intercourse and depressive symptoms. A total of 104 female participants (85.6% white, 74.03% partnered, 20.9 [3.01] years old) completed an online survey including demographic information, PROMIS Vaginal Discomfort Measure, PROMIS Depression Measure, and Revised UCLA Loneliness Scale. Pearson correlations and bootstrapped mediation analysis examined the relationships among pain during intercourse, loneliness, and depressive symptoms. Pain during intercourse, loneliness, and depressive symptoms were all significantly correlated (p < .05). Results of the mediation analysis indicated that loneliness was a significant mediator of the relationship between pain during intercourse and depressive symptoms (indirect effect = 0.077; 95% CI 0.05-0.19). After accounting for loneliness, pain during intercourse was not significantly related to depressive symptoms, suggesting that loneliness fully mediated the relationship between pain during intercourse and depressive symptoms. These findings are consistent with previous studies highlighting that pain during intercourse is related to depressive symptoms. The current study adds to that literature and suggests that more frequent and severe pain during intercourse leads to more loneliness, which then leads to increased depressive symptoms. This line of work has important implications for treating women who experience depressive symptoms and pain during intercourse.

Correction to: Loneliness Mediates the Relationship Between Pain During Intercourse and Depressive Symptoms Among Young Women

Due to an oversight on the authors' part, the original article was published without an Acknowledgements section. The correct Acknowledgements text is given below.

Sex and Race Differences in Pain Sensitization among Patients with Chronic Low Back Pain

Growing evidence suggests that chronic low back pain (CLBP) is associated with pain sensitization, and that there are sex and race disparities in CLBP. Given the sex and race differences in pain sensitization, this has been hypothesized as a mechanism contributing to the sex and race disparities in CLBP. This study examined sex and race differences in pain sensitization among patients with CLBP, as well as the role of catastrophizing as a potential mediator of those differences. The study found that compared with men, women required less pressure to produce deep muscle pain and rated mechanical punctate pain as more painful. Compared with non-Hispanic white patients, black patients demonstrated greater pain sensitivity for measures of deep muscle hyperalgesia and mechanical punctate pain. Furthermore, catastrophizing partially mediated the race differences in deep muscle pain such that black participants endorsed greater pain catastrophizing, which partially accounted for their increased sensitivity to, and temporal summation of, deep muscle pain. Taken together, these results support the need to further examine the role of catastrophizing and pain sensitization in the context of sex and race disparities in the experience of CLBP. PERSPECTIVE: This study identifies sex and race differences in pain sensitization among patients with CLBP. Further, it recognizes the role of catastrophizing as a contributor to such race differences. More research is needed to further dissect these complex relationships.

Pain-Related Rumination, But Not Magnification or Helplessness, Mediates Race and Sex Differences in Experimental Pain

Compared with white individuals and men, black individuals and women show a lower tolerance for experimental pain stimuli. Previous studies suggest that pain catastrophizing is important in this context, but little is known about which components of catastrophizing contribute to these race and sex differences. The purpose of the current study was to examine the individual components of catastrophizing (rumination, magnification, and helplessness) as candidate mediators of race and sex differences in experimental pain tolerance. Healthy undergraduates (N = 172, 74% female, 43.2% black) participated in a cold pressor task and completed a situation-specific version of the Pain Catastrophizing Scale. Black and female participants showed a lower pain tolerance than white (P < .01, d = .70) and male (P < .01, d = .55) participants, respectively. Multiple mediation analyses indicated that these race and sex differences were mediated by the rumination component of catastrophizing (indirect effect = -7.13, 95% confidence interval (CI), -16.20 to -1.96, and 5.75, 95% CI, .81-15.57, respectively) but not by the magnification (95% CI, -2.91 to 3.65 and -1.54 to 1.85, respectively) or helplessness (95% CI, -5.53 to 3.31 and -.72 to 5.38, respectively) components. This study provides new information about race and sex differences in pain and suggests that treatments targeting the rumination component of catastrophizing may help mitigate pain-related disparities.

PERSPECTIVE

This study suggests that differences in pain-related rumination, but not magnification or helplessness, are important contributors to race and sex differences in the pain experience. Interventions that target this maladaptive cognitive style may help reduce disparities in pain.

A comparison of race-related pain stereotypes held by White and Black individuals

Pain judgments are the basis for pain management. The purpose of this study was to assess Black and White participants' race-related pain stereotypes. Undergraduates (n=551) rated the pain sensitivity and willingness to report pain for the typical Black person, White person, and themselves. Participants, regardless of race, rated the typical White person as being more pain sensitive and more willing to report pain than the typical Black person. White participants rated themselves as less sensitive and less willing to report pain than same-race peers; however, Black participants rated themselves as more pain sensitive and more willing to report pain than same-race peers. These findings highlight similarities and differences in racial stereotypic pain beliefs held by Black and White individuals.

Differences in Pain Coping Between Black and White Americans: A Meta-Analysis

Compared with white individuals, black individuals experience greater pain across clinical and experimental modalities. These race differences may be due to differences in pain-related coping. Several studies examined the relationship between race and pain coping; however, no meta-analytic review has summarized this relationship or attempted to account for differences across studies. The goal of this meta-analytic review was to quantify race differences in the overall use of pain coping strategies as well as specific coping strategies. Relevant studies were identified using electronic databases, an ancestry search, and by contacting authors for unpublished data. Of 150 studies identified, 19 met inclusion criteria, resulting in 6,489 participants and 123 effect sizes. All of the included studies were conducted in the United States. Mean effect sizes were calculated using a random effects model. Compared with white individuals, black individuals used pain coping strategies more frequently overall (standardized mean difference [d] = .25, P < .01), with the largest differences observed for praying (d = .70) and catastrophizing (d = .40). White individuals engaged in task persistence more than black individuals (d = -.28). These results suggest that black individuals use coping strategies more frequently, specifically strategies associated with poorer pain outcomes. Future research should examine the extent to which the use of these strategies mediates race differences in the pain experience.

PERSPECTIVE

Results of this meta-analysis examining race differences in pain-related coping indicate that, compared with white individuals, black individuals use coping strategies more frequently, specifically those involving praying and catastrophizing. These differences in coping may help to explain race differences in the pain experience.

In Vivo praying and catastrophizing mediate the race differences in experimental pain sensitivity

Black individuals have a lower tolerance for experimental pain than white individuals. Black and white individuals also differ in their use of pain coping strategies, which may explain the race differences in pain sensitivity. We examined the extent to which situation-specific pain coping mediated black-white differences in pain sensitivity. We hypothesized that 1) black participants would demonstrate lower pain tolerance than white participants, 2) black participants would use different pain coping strategies than white participants, and 3) the differential use of these strategies would mediate the relationship between race and pain tolerance. Healthy college undergraduates (N = 190) participated in a cold pressor task and then completed the Coping Strategies Questionnaire-Revised to assess their situation-specific pain coping. Compared with white participants, black participants demonstrated lower pain tolerance, engaged in more situation-specific catastrophizing and praying, and ignored pain less frequently. Catastrophizing and praying were inversely related to pain tolerance and were significant mediators of the relationship between race and pain tolerance. The indirect effect of praying was stronger than that of catastrophizing. Race differences in pain sensitivity may be due, in part, to differences in the use of catastrophizing and praying as coping strategies. These results may help guide treatments addressing maladaptive pain coping.

PERSPECTIVE

This study suggests that race differences in pain sensitivity may be due, in part, to the differential use of catastrophizing and praying strategies. Psychosocial treatments for pain should encourage patients to take an active role in their pain management.

A comparison of viruses infecting two different Chlorella-like green algae

Five plaque-forming viruses (Pbi viruses) of the unicellular, eukaryotic, exsymbiotic Chlorella-like green alga strain Pbi were isolated from fresh water collected in Germany. The viruses were compared to two previously characterized plaque-forming viruses (NC64A viruses) of Chlorella strain NC64A. The Pbi viruses do not infect Chlorella NC64A and vice versa. Like the NC64A viruses the Pbi viruses are large polyhedron with a diameter of 140 to 150 nm, are chloroform sensitive, have many structural proteins, and have large dsDNA genomes of at least 300 kb. However, the Pbi viruses are serologically distinct from the NC64A viruses. The five Pbi virus genomes contain 5-methylcytosine, which varied from 14.2 to 43.1% of the cytosine, and two of them also contained N6-methyladenine. DNAs from the Pbi viruses hybridized poorly with the two NC64A virus DNAs and they have a higher guanine plus cytosine content (ca. 46%) than the NC64A virus DNAs (ca. 40%).