Psychosocial predictors in the transition from acute to chronic pain: a systematic review

Use of Complementary and Integrative Health Therapies Prior to Intensive Functional Restoration in Active Duty Service Members with Chronic Pain

OBJECTIVE

Psychosocial factors are known to predict chronic pain, and the use of complementary and integrative health (CIH) therapies to address pain is emerging among military population. However, conflicting results on pain outcomes warrant additional research. This study aimed to (1) evaluate the benefit of adding a CIH pain management program to standard rehabilitative care (SRC), as compared to SRC alone, as precursor to an intensive functional restoration (FR) program; (2) identify factors that predict improvement in pain outcomes following treatment; and (3) determine the proportion of participants who experience clinically meaningful response.

DESIGN

Pragmatic randomized controlled clinical trial. Participants were randomized to a 3-week course of either SRC alone or SRC+CIH (stage 1), followed by a 3- to 6-week course of FR (stage 2).

SETTING AND SUBJECTS

Active duty service members with chronic pain.

METHODS

Participants completed either SRC alone or SRC+CIH (stage 1), followed by a course of FR (stage 2). Patient-reported and provider-determined outcomes were collected at baseline, after stage 1, and after stage 2. A covariance pattern model with unstructured residual covariance matrix was used to compare treatment arms while accounting for dependency due to repeated measurements.

RESULTS

A total of 210 service members participated. Most were Army (82%) and male (84%). Participants randomized to the SRC+CIH intervention had greater improvement in the pain impact score than those in the SRC alone group. Predictors of outcomes were baseline impact score, anger, depression, and educational status.

CONCLUSIONS

This study found that military service members with the highest pain impact benefit the most from interdisciplinary pain care.

Older Adult Use and Outcomes in a Digital Musculoskeletal (MSK) Program, by Generation

Objective: We investigated use and clinical outcomes in a digital musculoskeletal (MSK) program, by generation.

Method: This longitudinal study uses retrospective data collected online or by app. The study included adults with 12 or more weeks of pain who took part in a digital MSK program. We compared Gen Z and Millennials, Gen X, working age Baby Boomers, and retiree age Baby Boomer and Silent Generation. Program use outcomes were program start, program completion, and number of exercises, educational articles, and messages to coaches. Clinical outcomes were changes in pain, depression, and anxiety from baseline to 12 weeks. We calculated descriptive statistics and conducted adjusted regression models.

Results: Odds of starting the program were significantly higher for Gen Xers (OR: 1.12) and working age Baby Boomers (OR: 1.37) vs. Gen Zers and Millennials. Compared to Gen Zers and Millennials, we observed significantly higher odds of program completion among Gen Xers (OR: 1.62), working age Baby Boomers (OR: 2.24), and retirees (OR: 2.36). Compared to Gen Zers and Millennials, retirees had 19 more exercise sessions (IRR: 1.69), accessed 11 more articles (IRR: 1.84), and sent 4 more messages to coaches (IRR: 1.26). Compared to Gen Z and Millennials, we observed no significant differences in change in pain for Gen Xers, working age Baby Boomers, or retirees.

Conclusions: Adults from multiple generations took part in a digital MSK program. Findings suggest that older generations used a digital MSK program more than younger generations, but had similar pain outcomes.

The influence of a MOBile-based video Instruction for Low back pain (MOBIL) on initial care decisions made by primary care providers: a randomized controlled trial

BACKGROUND

Adherence to guidelines for back pain continues to be a challenge, prompting strategies focused on improving education around biopsychosocial frameworks.

OBJECTIVE

Assess the influence of an interactive educational mobile app for patients on initial care decisions made for low back pain by the primary care provider. The secondary aim was to compare changes in self-reported pain and function between groups.

METHODS

This was a randomized controlled trial involving patients consulting for an initial episode of low back pain. The intervention was a mobile video-based education session (Truth About Low Back Pain) compared to usual care. The app focused on addressing maladaptive beliefs typically associated with higher risk of receiving low-value care options. The primary outcome was initial medical utilization decisions made by primary care practitioners (x-rays, MRIs, opioid prescriptions, injections, procedures) and secondary outcomes included PROMIS pain interference and physical function subscales at 1 and 6 months, and total medical costs.

RESULTS

Of 208 participants (71.2% male; mean age 35.4 years), rates of opioid prescriptions, advanced imaging, analgesic patches, spine injections, and physical therapy use were lower in the education group, but the differences were not significant. Total back-related medical costs for 1 year (mean diff = $132; P = 0.63) and none of the 6-month PROMIS subscales were significantly different between groups. Results were no different in opioid-naïve subjects. Instead, prior opioid use and high-risk of poor prognosis on the STarT Back Screening Tool predicted 1-year back pain-related costs and healthcare utilization, regardless of intervention.

CONCLUSION

Factors that influence medical treatment decisions and guideline-concordant care are complex. This particular patient education approach directed at patients did not appear to influence healthcare decisions made by primary care providers. Future studies should focus on high-risk populations and/or the impact of including the medical provider as an active part of the educational process.

TRIAL REGISTRATION

clinicaltrials.gov NCT02777983 .

The anatomy of pain and suffering in the brain and its clinical implications

Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Chronic pain, with a prevalence of 20-30 % is the major cause of human suffering worldwide, because effective, specific and safe therapies have yet to be developed. It is unevenly distributed among sexes, with women experiencing more pain and suffering. Chronic pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral 'painfulness' pathway, a medial 'suffering' pathway and a descending pain inhibitory pathway. One may have pain(fullness) without suffering and suffering without pain(fullness). Pain sensation leads to suffering via a cognitive, emotional and autonomic processing, and is expressed as anger, fear, frustration, anxiety and depression. The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness. Genetic and epigenetic influences trigger chronic neuroinflammatory changes which are involved in transitioning from acute to chronic pain. Based on the concept of the Bayesian brain, pain (and suffering) can be regarded as the consequence of an imbalance between the two ascending and the descending pain inhibitory pathways under control of the reward system. The therapeutic clinical implications of this simple pain model are obvious. After categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathway in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.

Pain Appraisals in Patients with Physical Injury: Assessing the Role of Distress Tolerance in the Relationship between Depression and Pain Catastrophizing

Pain is a complex construct contributing to significant impairment, particularly among physically injured patients seeking treatment in trauma and orthopedic surgery settings in which social workers are an integral component of care. The biopsychosocial theory, fear-avoidance, and cognitive mediation models of pain suggest that psychological factors (for example, depression) affect one's ability to tolerate distress, leading to negative pain appraisals, such as catastrophizing. This study examined whether distress tolerance serves as a mechanism by which depression is associated with pain catastrophizing. We administered a health survey to outpatient trauma and orthopedic surgery clinic patients who were using opioid medications; 84 patients were included in the final analysis; 39.3 percent screened positive for depression. A multilevel mediation model using structural equation modeling revealed a significant direct effect from depression to pain catastrophizing (ß = .31, z = 3.96, p < .001) and a significant indirect effect by distress tolerance (Δß = .27, z = 3.84, p < .001). These results, which suggest that distress tolerance partially mediated the path from depression to pain catastrophizing, can inform social workers and other members of the multidisciplinary team about both the critical role of psychosocial factors after injury and interventions to improve postinjury recovery.

Agreement and screening accuracy between physical therapists ratings and the Ӧrebro Musculoskeletal Pain Questionnaire in screening for risk of chronic pain during Musculoskeletal evaluation

Introduction: Identifying patients at risk for chronic musculoskeletal pain can inform evaluation and treatment decisions. The ability of physical therapists to assess patients' risk for chronic pain without use of validated tools has been questioned. The Ӧrebro Musculoskeletal Pain Questionnaire (OMPQ) is used to determine risk for chronic pain.Methods: The aim of this pragmatic study was to prospectively quantify the agreement between physical therapists' assessment of patients' risk for chronic symptoms compared to the OMPQ. Patients were asked to complete the OMPQ during the initial visit. Physical therapists, blinded to OMPQ risk classification, carried out their usual patient assessment procedures. The physical therapists rated patients as either high or low risk for chronic pain based on their clinical assessment. Agreement between therapist and OMPQ was determined using Cohen's Kappa (κ) and screening accuracy compared clinician risk to the OMPQ risk classification (reference standard) by way of contingency table analysis.Results: Ninety-six (96) patients' risk classifications and 15 corresponding physical therapists' risk estimates were available for analysis. The OMPQ identified a 47% prevalence for high risk of chronic pain. Agreement (κ and 95% confidence interval) between physical therapist rating and OMPQ was slight, κ = 0.272 (0.033-0.421), p = .026. Therapists' sensitivity and specificity (95% CI) for determining risk classifications were 60.0% (44.3-74.3) and 62.8% (48.1-75.6), respectively. The positive and negative likelihood ratios (95% CI) were 1.61 (1.05-2.47) and 0.64 (0.42-0.97).Discussion: The use of validated self-report questionnaires are recommended to supplement clinician prognosis for patients at risk of chronic musculoskeletal pain.

Cognitive, emotional, and somatosensory behavior in professional dancers with acute and chronic pain

BACKGROUND

Dance has been linked in a complex manner to pain and the physical and psychological peculiarities of this discipline could influence pain perception and chronicity of pain.

OBJECTIVE

To determine the differences in cognitive, emotional, and somatosensory symptoms between dancers with acute versus chronic pain.

DESIGN

A cross-sectional study of professional dancers with pain.

SETTING

Higher conservatory of dance.

PARTICIPANTS

Thirty-four professional dancers experiencing pain were included. The cohort was divided into two subgroups: those with acute pain (<3 months duration) and those with chronic pain (>3 months duration).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Pain intensity (as measured by the visual analogue scale or VAS), pressure pain threshold (PPT), Pain Catastrophizing Scale (PCS), pain-related fear of movement (Tampa Scale of Kinesiophobia [TSK-11]), fear avoidance beliefs (Fear-Avoidance Beliefs Questionnaire [FABQ]), self-efficacy (Chronic Pain Self-Efficacy Scale [CPSS]). and chronic pain severity (Chronic Pain Graded Scale [CPGS]).

RESULTS

Dancers with chronic pain reported higher levels of pain intensity in daily activities (p < .01; t = 3.42; d = 1.17) and during exercise/dance (p = .02; t = 2.82; d = 0.82), as well as lower PPT in lumbar (p = .03; t = 3.22; d = 1.1) and tibialis regions (p = .01; t = 2.51; d = 0.86). Dancers with acute pain experienced worse psychological symptoms indicated by the fear of harm subscale of TSK-11 (p = .04; t = -2.08; d = 0.72), physical activity subscale of FABQ (p = .03; t = -2.27; d = 0.78), and pain management subscale of CPSS (p = .01; t = -2.76; d = 0.94) and lower scores for CPGS scale (p = .01; t = 2.99; d = 0.7 to 1.26).

CONCLUSIONS

The results showed differences in pain intensity and PPT revealing higher values in dancers with chronic pain. It is possible that the physical and psychological characteristics of dancers, as well as the sociocultural aspects of this discipline, could influence the way in which this population interprets pain.

Effects of Chronic Pain Treatment on Altered Functional and Metabolic Activities in the Brain: A Systematic Review and Meta-Analysis of Functional Neuroimaging Studies

Previous studies have identified altered brain changes in chronic pain patients, however, it remains unclear whether these changes are reversible. We summarized the neural and molecular changes in patients with chronic pain and employed a meta-analysis approach to quantify the changes. We included 75 studies and 11 of these 75 studies were included in the activation likelihood estimation (ALE) analysis. In the 62 functional magnetic resonance imaging (fMRI) studies, the primary somatosensory and motor cortex (SI and MI), thalamus, insula, and anterior cingulate cortex (ACC) showed significantly decreased activity after the treatments compared to baseline. In the 13 positron emission tomography (PET) studies, the SI, MI, thalamus, and insula showed significantly increased glucose uptake, blood flow, and opioid-receptor binding potentials after the treatments compared to baseline. A meta-analysis of fMRI studies in patients with chronic pain, during pain-related tasks, showed a significant deactivation likelihood cluster in the left medial posterior thalamus. Further studies are warranted to understand brain reorganization in patients with chronic pain compared to the normal state, in terms of its relationship with symptom reduction and baseline conditions.

Back Pain in Outer Space

Space travel has grown during the past 2 decades, and is expected to surge in the future with the establishment of an American Space Force, businesses specializing in commercial space travel, and National Aeronautics and Space Administration's planned sustained presence on the moon. Accompanying this rise, treating physicians are bracing for a concomitant increase in space-related medical problems, including back pain. Back pain is highly prevalent in astronauts and space travelers, with most cases being transient and self-limiting (space adaptation back pain). Pathophysiologic changes that affect the spine occur during space travel and may be attributed to microgravity, rapid acceleration and deceleration, and increased radiation. These include a loss of spinal curvature, spinal muscle atrophy, a higher rate of disc herniation, decreased proteoglycan and collagen content in intervertebral discs, and a reduction in bone density that may predispose people to vertebral endplate fractures. In this article, the authors discuss epidemiology, pathophysiology, prevention, treatment, and future research.

Bodily pain in survivors of acute respiratory distress syndrome: A 1-year longitudinal follow-up study

PURPOSE

Acute respiratory distress syndrome (ARDS) survivors frequently experience bodily pain during recovery after the intensive care unit. Longitudinal course, risk factors and associations with physical and neuropsychological health is lacking.

METHODS

We collected self-reported pain using the Short Form-36 Bodily Pain (SF-36 BP) scale, normalized for sex and age (range: 0-100; higher score = less pain), along with physical and mental health measures in a multi-center, prospective cohort of 826 ARDS survivors at 6- and 12-month follow-up. We examined baseline and ICU variables' associations with pain via separate unadjusted regression models.

RESULTS

Pain prevalence (SF-36 BP ≤40) was 45% and 42% at 6 and 12 months, respectively. Among 706 patients with both 6- and 12-month data, 34% reported pain at both timepoints. Pre-ARDS employment was associated with less pain at 6-months (mean difference (standard error), 5.7 (0.9), p < 0.001) and 12-months (6.3 (0.9), p < 0.001); smoking history was associated with greater pain (-5.0 (0.9), p < 0.001, and - 5.4 (1.0), p < 0.001, respectively). In-ICU opioid use was associated with greater pain (-6.3 (2.7), p = 0.02, and - 7.3 (2.8), p = 0.01, respectively). At 6 months, 174 (22%) patients reported co-occurring pain, depression and anxiety, and 227 (33%) reported co-occurring pain and impaired physical function.

CONCLUSION

Nearly half of ARDS survivors reported bodily pain at 6- and 12-month follow-up; one-third reported pain at both time points. Pre-ARDS unemployment, smoking history, and in-ICU opioid use may identify patients who report greater pain during recovery. Given its frequent co-occurrence, clinicians should manage both physical and neuropsychological issues when pain is reported.

Effectiveness of Pain Neurophysiology Education on Musculoskeletal Pain: A Systematic Review and Meta-Analysis

Objectives

To estimate the effectiveness and safety of Pain Neurophysiology Education (PNE) on pain, disability, and psychological distress at post-intervention and long-term (closest to twelve months after initiating the intervention) in musculoskeletal pain (MSKP).

Methods

Randomized Controlled Trials (RCT) were identified in six engines, reference lists, ClinicalTrials.gov, and by contacting key researches. Risk of bias was assessed using Cochrane Collaboration Risk of Bias Tool 2.0. Meta-analyses, using Restricted Maximum Likelihood Method, were conducted to estimate standardized mean differences (SMD) and overall quality of evidence was evaluated according to GRADE.

Results

In total, 18 RCTs (n = 1,585) were included. There was small to moderate effects of PNE on pain at post-intervention and long-term: SMD = -0.32 (95% confidence interval [CI]: −.58; −.05) and SMD = −0.40 (95% CI: −.78; −.03), respectively. On disability, PNE had a small effect at post-intervention: SMD = -0.17 (95% CI: −.34; −.01) but was insignificant at long-term: SMD = −0.27 (95% CI: −.59; .06). Likewise, there was a small to moderate effect on psychological distress at post-intervention: SMD = −0.36 (95% CI: −.67; −.06) but was insignificant at long-term: SMD = −0.37 (95% CI: −.75; .01). Quality of evidence was low across all outcomes. Additional analyses showed significant effects of PNE, corresponding to moderate effects, on pain and psychological distress at both time points in chronic MSKP.

Conclusions

Overall quality of evidence was low, supporting PNE being safe and having small to moderate effects on pain at both time points, and on disability as well as psychological distress at post-intervention.

Modifiable Psychological Factors Affecting Functioning in Fibromyalgia

Objective: To examine the role of several interrelated, potentially modifiable psychological factors (i.e., mindfulness and catastrophizing) in influencing patient-reported functioning. Methods: In this cross-sectional study, 107 patients with fibromyalgia completed self-report assessments of pain severity, functioning and impact of symptoms, mindfulness, and pain catastrophizing. Linear regression and bootstrapping mediation analyses were performed to assess the relationships between these factors. Results: Pain intensity was significantly and positively associated with pain catastrophizing and impact of fibromyalgia on functioning. Linear regression analyses indicated that pain intensity, catastrophizing, and mindfulness affect functioning in fibromyalgia. Follow-up mediation analysis revealed a significant indirect effect of pain catastrophizing on the relationship between pain intensity and fibromyalgia functioning. Conclusion: Individuals with fibromyalgia who have higher levels of pain and catastrophizing, and lower levels of mindfulness, are more likely to experience impaired functioning. Our findings suggest that pain catastrophizing appears to be an especially important variable contributing to reduced functioning in women with fibromyalgia. Therefore, catastrophizing-reducing treatments (e.g., cognitive behavioral therapy) are likely to have direct, beneficial impacts on functioning.

Predicting the Transition to Chronic Pain 6 Months After an Emergency Department Visit for Acute Pain: A Prospective Cohort Study

BACKGROUND

Acute pain can transition to chronic pain, a potentially debilitating illness.

OBJECTIVE

We determined how often acute pain transitions to chronic pain among patients in the emergency department (ED) and whether persistent pain 1 week after the ED visit was associated with chronic pain.

METHODS

An observational cohort study conducted in two EDs. We included adults with acute pain (≤10 days) if an oral opioid was prescribed. Exclusion criteria were recent opioid use and use of any analgesics regularly prior to onset of the pain. Research associates interviewed patients during the ED visit and 1 week and 6 months later. The primary outcome, chronic pain, was defined as pain on > 50% of days since ED discharge. We constructed logistic regression models to evaluate the association between persistent pain 1 week after an ED visit and chronic pain, while adjusting for demographic and treatment variables.

RESULTS

During a 9-month period, we approached 733 patients for participation and enrolled 484; 450 of 484 (93%) provided 1-week outcomes data and 410 of 484 (85%) provided 6-month outcomes data. One week after the ED visit, 348 of 453 (77%; 95% confidence interval [CI] 73-80%) patients reported pain in the affected area. New-onset chronic pain at 6 months was reported by 110 of 408 (27%; 95% CI 23-31%) patients. Presence of pain 1 week after ED visit was associated with chronic pain (odds ratio 3.6; 95% CI 1.6-8.5).

CONCLUSIONS

About one-quarter of ED patients with acute pain transition to chronic pain within 6 months. Persistence of pain 1 week after the ED visit can identify patients at risk of transition.

Exposure to greenspaces could reduce the high global burden of pain

Painful conditions are among the leading causes of years lived with disability, and may increase following the coronavirus pandemic, which has led to temporary closure of some healthcare services for people with chronic pain. To reduce this burden, novel, cost-effective and accessible interventions are required. We propose that greenspace exposure may be one such intervention. Drawing on evidence from neuroscience, physiology, microbiology, and psychology, we articulate how and why exposure to greenspaces could improve pain outcomes and reduce the high global burden of pain. Greenspace exposure potentially provides opportunities to benefit from known or proposed health-enhancing components of nature, such as environmental microbiomes, phytoncides, negative air ions, sunlight, and the sights and sounds of nature itself. We review the established and potential links between these specific exposures and pain outcomes. While further research is required to determine possible causal links between greenspace exposure and pain outcomes, we suggest that there is already sufficient evidence to help reduce the global burden of pain by improving access and exposure to quality greenspaces.

Should musicians play in pain?

Musculoskeletal symptoms, including pain, are often experienced by musicians at all levels. These symptoms may have a detrimental impact on musicians' personal and work lives, and may also impact upon the ensembles they work within. Providing musicians with appropriate, evidence-based advice regarding pain management is therefore paramount. In this review, we aim to improve the advice given to musicians regarding playing when in pain, by answering the question 'should musicians play in pain?'. This multidisciplinary narrative review draws upon contemporary pain science, including factors associated with poorer prognoses for those in pain, as well as the reported experiences of musicians with pain (including those who have taken time off from playing). Our current understanding of pain science provides further support for the potential for consequences related to avoiding activities due to pain. Pain is modulated by a number of neuro-immunological processes and is influenced by a range of psychosocial factors. Taking time off from playing might therefore not have any benefit. Importantly, one of the leading causes of a transition from acute to chronic pain is fear-avoidance behaviour (e.g. not playing when in pain); hence, encouraging such behaviour cannot be supported. Musicians who have taken time off from playing due to pain have experienced a range of consequences, including emotional and financial consequences. These experiences indicate that there are potential negative consequences related to taking time off from playing which need to be weighed against any benefits. We conclude that musicians should not necessarily be advised to take time off from playing to manage their pain, in keeping with current best practice for pain management. Instead, we recommend that musicians be educated on contemporary pain science and when to seek treatment from a health professional for individualised advice to reduce the burden of musicians' pain.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Self-Perceived Pain in Chinese Patients With Cancer

Background

Pain is one of the most burdensome and prevalent symptoms cancer patient report and it has severe negative impact on patient's quality of life. The aim of this study is to estimate the prevalence of pain and to test the association between demographic, clinical, psychological factors, and self-assessed pain in Chinese cancer population.

Methods

A total of 553 cancer patients were recruited in this cross-sectional study. Patient's basic demographic data was collected by a study-designed information sheet, and patient's pain, sleep disturbance and psychological distress were assessed by several validated measurements (MPQ-SF, AIS, FoP-Q-SF, PHQ-9, and GAD-7). Descriptive statistics and hierarchical multiple regression analyses were performed.

Results

Of the 553 patients, 411 (74.32%) patients reported that they experience some degree of pain. Fear of progression, anxiety, insomnia, and depressive symptoms were significantly associated with different subscales and the overall pain score in bivariate correlation matrix. Insomnia, depressive symptoms, and fear of cancer progression were significant independent factors of cancer pain on multivariate analyses.

Conclusion

Psychological factors play a great role in the relationship between objective pathophysiology and patient's subjective experience of pain. It is important to evaluate each individual in detail with respect to psychological distress and pain severity when planning treatment and rehabilitation.

Social Relationship Quality Among Patients With Chronic Pain: A Population-Based Sample

Objective

Chronic daily pain is experienced by 11.2% of United States adults and psychosocial factors have significant impact on self-reported pain. Most research in this area has focused on pain-related conditions, not the general population. This study sought to understand the associations between clinically significant chronic pain and multiple dimensions of social relationship quality in a general population.

Methods

A cross-sectional survey was deployed and adjusted logistic regression models were constructed for chronic pain against independent social support domains. The moderating effect of self-rated health on social support quality was explored.

Results

Of all, 26.1% of surveys were completed (3920/15 000) and 18.8% reported clinically significant chronic pain. Patients with chronic pain had lower friendship quality (aOR = 0.78; 0.64-0.94) and higher perceived rejection (aOR = 1.26; 1.04-1.53) and perceived hostility (aOR = 1.26; 1.05-1.52). Within our moderation analysis, chronic pain patients with low self-rated health had higher odds of low friendship quality, high loneliness, and high perceived rejection.

Conclusions

Chronic pain patients experience social relationships differently than those without, and self-rated health differentially impacts these perceptions.

Chronic pain after hand-assisted laparoscopic donor nephrectomy

BACKGROUND

Data on chronic pain after kidney donation are sparse. The aim of this study was to assess the incidence of chronic pain after hand-assisted laparoscopic nephrectomy.

METHODS

Living kidney donors who donated between 2011 and 2017 at the University Medical Centre Groningen were included. All patients underwent hand-assisted laparoscopic donor nephrectomy. Postdonation pain and movement disabilities were assessed using the Carolinas Comfort Scale (CCS) and a visual analogue scale (VAS). The prevalence, severity of pain and the need for analgesics were reported.

RESULTS

Some 333 living kidney donors with a mean age of 56 years were included. At a median of 19 (i.q.r. 10-33) months after donation, 82 donors (24·6 per cent) had a CCS score above 0, of which 58 (71 per cent) had a CCS score of at least 2 and 57 (70 per cent) reported movement limitations. Some 110 donors (33·0 per cent) had a VAS score of more than 0. Complaints mainly occurred during bending over (12·3 per cent) and exercising (12·4 per cent). Thirty-two donors (9·7 per cent) required analgesics during follow-up between donation and the time of measurement, and six of 82 (7 per cent) reported chronic inguinal pain. In multivariable analysis, donor age (odds ratio (OR) 0·97, 95 per cent c.i. 0·95 to 0·99; P = 0·020) and length of hospital stay (OR 1·21, 1·01 to 1·51; P = 0·041) were independently associated with chronic pain.

CONCLUSION

One-quarter of donors experienced chronic postdonation pain or discomfort, most of which was bothersome. Younger donors and those with a longer postoperative hospital stay had more symptoms.

Could epigenetics help explain racial disparities in chronic pain?

African Americans disproportionately suffer more severe and debilitating morbidity from chronic pain than do non-Hispanic Whites. These differences may arise from differential exposure to psychosocial and environmental factors such as adverse childhood experiences, racial discrimination, low socioeconomic status, and depression, all of which have been associated with chronic stress and chronic pain. Race, as a social construct, makes it such that African Americans are more likely to experience different early life conditions, which may induce epigenetic changes that sustain racial differences in chronic pain. Epigenetics is one mechanism by which environmental factors such as childhood stress, racial discrimination, economic hardship, and depression can affect gene expression without altering the underlying genetic sequence. This article provides a narrative review of the literature on epigenetics as a mechanism by which differential environmental exposure could explain racial differences in chronic pain. Most studies of epigenetic changes in chronic pain examine DNA methylation. DNA methylation is altered in the glucocorticoid (stress response) receptor gene, NR3C1, which has been associated with depression, childhood stress, low socioeconomic status, and chronic pain. Similarly, DNA methylation patterns of immune cytokine genes have been associated with chronic stress states. Thus, DNA methylation changes may play an essential role in the epigenetic modulation of chronic pain in different races with a higher incidence of epigenetic alterations contributing to more severe and disabling chronic pain in African Americans.

Paradoxical Sleep Deprivation Aggravates and Prolongs Incision-Induced Pain Hypersensitivity via BDNF Signaling-Mediated Descending Facilitation in Rats

The mechanisms underlying the pronociceptive effect of paradoxical sleep deprivation (PSD) are not fully established. The modulation of BDNF signaling-mediated descending facilitation from the rostral ventromedial medulla (RVM) of brain stem has been demonstrated in persistent pain models of inflammatory pain, but not in incisional pain model. Recent study has shown that PSD increases the expression of brain-derived neurotrophic factor (BDNF) in the brainstem structure. Therefore, in the current study, we asked whether the BDNF signaling-mediated descending facilitation was involved in the PSD-induced pronociceptive effect on incisional pain and delay the recovery period of postoperative pain in rats. Our results found that a preoperative 24 h PSD significantly aggravated the pain hypersensitivity after incision and prolonged the duration of postoperative pain. The lesions of ipsilateral dorsolateral funiculus partly reversed the PSD-induced pronociceptive effect on incisional pain. Interestingly, the 24 h PSD, but not incision significantly enhanced the levels of BDNF protein expression in the RVM areas of rats. Furthermore, at 1 day or 4 days after incision, intra-RVM microinjection of a BDNF antibody partly reversed the PSD-induced pronociceptive effects in incisional rats, while it did not change the cumulative pain scores and paw withdrawal thresholds in rats receiving only plantar incision. These findings suggest that the preoperative PSD may aggravate and prolong the incision-induced pain hypersensitivity via BDNF signaling-mediated descending facilitation.