The IASP classification of chronic pain for ICD-11: chronic primary pain

Co-creating a Choosing Wisely leaflet supporting the reduction of imaging usage in low back pain management - A multi-method study

OBJECTIVE

The objective was to co-create an information resource in the form of a leaflet, to be distributed in clinical settings, websites or social media targeting people with low back pain.

METHODS

This multi-method study was conducted in four stages: literature search, input from practice consultants, program theory development, and think-aloud interviews with people experiencing low back pain. Each stage was followed by a consensus meeting in which the steering group refined the leaflet based on the emerging knowledge.

RESULTS

The literature search highlighted patients' need for easy-to-understand information about their back pain diagnosis, management strategies, social activities, work and solutions for supported self-management strategies. Practice consultants emphasized concise, relatable content. The program theory identified potential mechanisms for content creation, development, and implementation of the leaflet, such as addressing patient concerns, reducing diagnostic uncertainty, insights into management options, and validation. Think-aloud interviews with 18 people living with low back pain informed the iteration of the leaflet, enhancing language clarification and content comprehension.

CONCLUSIONS

We co-created a new Choosing Wisely leaflet, created with end-users in mind, specifically focused on reducing unnecessary imaging for low back pain.

PRACTICE IMPLICATIONS

This leaflet may support clinical settings in delivering evidence-based approaches and supporting self-management.

The current state of digital manikins to support pain self-reporting: a systematic literature review

This systematic literature review aimed to explore the current state of digital manikins to support pain self-reporting and to explore the extent to which manikins had progressed along the translational pathway. We systematically searched six electronic databases using a combination of key words and MeSH terms for "pain" and "manikin" to identify original studies in English that used a digital pain manikin for collecting information from adults with any condition. We extracted and descriptively synthesised data on the characteristics of studies and digital pain manikins and mapped them to a stage of the translational pathway (ie, design, testing, metric validation, and diffusion). We screened 6,189 articles, of which we included 104. Articles reported on 31 unique digital pain manikins. Most studies were conducted in Europe (n = 60; 58%), recruited people with pain/painful conditions (n = 69; 66%) from clinical settings (n = 67; 64%). Of the 31 manikins, the majority were two-dimensional (n = 21; 68%) with a front and back body view (n = 18; 58%) and allowed users to draw their pain on any area of the manikin (n = 23; 74%). Most manikins were still in the development and testing stages (n = 23; 74%). Only eight (26%) had progressed fully through the translational pathway, taking between 7 and 20 years to go from early development to diffusion. We found a substantial number of mostly two-dimensional digital pain manikins reported on in the last decade. However, most were still at early stages of the translational pathway, with only few having progressed through to diffusion into research and health care settings.

Chronic pain and its association with cognitive decline and brain function abnormalities in older adults: Insights from EEG and neuropsychological assessment

Studies examining the interplay between chronic pain, cognitive function, and functional brain abnormalities in older adults are scarce. To address this gap, we administered a series of neuropsychological tests and recorded electroencephalography (EEG) data during resting-state conditions in 26 older adults with chronic pain (CPOA), 30 pain-free older adults (OA), and 31 younger adults (YA). CPOA demonstrated poorer performance compared to OA on the Stroop test, the Wisconsin Card Sorting Test (WCST) and Digit Span. Both groups of older adults exhibited higher beta activity compared to younger adults, with CPOA displaying particularly elevated beta-2 activity localized in the posterior cingulate cortex compared to OA. Correlational analyses indicated that in CPOA participants, heightened beta activity was linked to decreased performance on the WCST. Conversely, in OA, we observed a positive correlation between beta activity and performance on the WCST. Overall, our findings suggest that the cumulative impact of pain in aging would diminish the effectiveness of the functional compensatory mechanisms that occur during healthy aging, exacerbating cognitive decline.

The role of emotions reported in the emergency department in four-month chronic pain development: Effects of sadness and anger

OBJECTIVE

This study aims to assess whether the emotions experienced during an urgent health problem represent risk factors for developing chronic pain.

METHOD

A pain study was carried out as part of a randomized multicentre study on the prevention of post-concussion syndrome and post-traumatic stress syndrome (SOFTER) following emergency hospitalisation. Nine hundred and fourteen patients not suffering from chronic pain at admission provided information on the presence and intensity of eight emotions (anger, fear, regret, sadness, relief, contentment, joy, and interest) during their stay at the emergency department. Four months later, they were called to assess if chronic pain had developed. The predisposition to experience these emotions prior to the emergency room was questioned at this occasion.

RESULTS

Four months after their admission to the emergency department (ED), 30 % of the patients described experiencing chronic pain. Adjusted for patient's perception of own health, intensity of acute pain, reason for visit and level of education at the time of admission, sadness (OR = 1.5 95 % CI = [1.1-2.2]) and anger (OR = 1.6 95 % CI = [1.1-2.5]) declared in the ED were predictive of pain status at four months. By taking into account patient pre-disposition to feel each of these two emotions, we observed a significantly higher risk of chronic pain at four months among patients pre-disposed to anger who declared a relatively strong anger during their time spent in the ED (OR = 2.90, IC = 1.12-7.52).

CONCLUSION

This study shows that the emotional state of patients admitted to the ED must be taken into consideration in order to detect people likely to experience chronic pain and therefore offer personalised preventive treatment. Further studies will be necessary to better comprehend the role played by emotions in the development of chronic pain.

Complaints and pain predominance in running-related injuries: A Bayesian inference analyses

INTRODUCTION

Evidence on running-related injuries (RRIs) complaints/symptoms is scarce, raising concerns about defining RRIs by pain alone and highlighting the lack of data on pain's symptoms predominance among runners sustaining injuries.

AIMS

To investigate the main complaints/symptoms of RRIs and to investigate how running-related pain is distributed across duration and pain symptoms predominance.

METHODS

A total of 346 adult runners with ≥3 months of running experience, with no history of surgery and sustaining running-related injuries were included. The outcomes were the complaints/symptoms of RRIs, and the classifications of running-related pain regarding duration (acute or persistent) and pain symptoms predominance (nociceptive, neuropathic and nociplastic). Bayesian analyses estimated proportions using non-informative priors due to a lack of prior scientific evidence on RRIs complaints/symptoms.

RESULTS

The main complaint/symptom of running-related injuries was pain (94.5%, 95% credible interval [CrI] 92.0 to 96.7, n = 327), followed by foot blisters (11.0%, 95% CrI 7.9 to 14.4, n = 38). Persistent pain with nociceptive symptoms (51.1%, 95% CrI 45.6 to 56.5, n = 167) and acute pain with nociceptive symptoms (45.9%, 95% CrI 40.5 to 51.2, n = 150) were the most frequent pain classifications. Cases of 'acute neuropathic-like symptoms' were not reported.

DISCUSSION

Study suggests pain is not the sole symptom of running injuries. Broader definitions capturing any complaints may better represent injury burden for runners.

CONCLUSION

'Musculoskeletal pain' is the main complaint of RRIs. A quarter of injured runners also experience additional complaints besides pain. Our study highlighted prevalent pain symptoms predominance, with 'persistent pain with nociceptive symptoms' and 'acute pain with nociceptive symptoms' being the most common.

Who is the patient with resistant myofascial temporomandibular disorders pain? A somatosensory, psychosocial, and genetic characterization

BACKGROUND

Resistance to treatments have been assessed in chronic conditions such as migraine, but not in temporomandibular disorders (TMD). This study aimed to identify factors that influence treatment outcome in patients with myofascial TMD pain.

METHODS

Seventy-two females were divided into three groups: TMD successfully treated (TMD-S, n = 24), TMD resistant to treatment (TMD-R, n = 24) and Controls without TMD (n = 24). Criteria for resistance included: less than 30% pain reduction after three months of conservative treatment and an average pain intensity > 50 mm (VAS) during the last month. Quantitative sensory testing (QST), psychosocial status and genetic polymorphisms were examined. ANOVA on ranks (psychosocial variables) with Dunn's test as post-hoc or ANOVA (age and somatosensory variables) with Tukey test as post-hoc test, and Dwass-Steel-Critchlow-Fligner test (genetic variables) were used for univariate groups comparisons. Multivariate statistics were used to identify outcomes that separated the groups.

RESULTS

QST assessment revealed lower baseline pressure pain threshold and higher wind-up ratio in the trigeminally and spinally innervated areas in the TMD-R group compared with the other groups (p = 0.01). Also, the TMD-R group presented higher values in all assessed psychosocial variables (p < 0.01) and higher prevalence of the HTR1A polymorphism rs6295 (p = 0.02) compared with the other groups at baseline. Multivariate analysis showed that the three variables that distinguished the best between TMD-R and TMD-S were sleeping quality, central sensitization, and depressive symptoms.

CONCLUSION

Psychosocial, somatosensory, and genetic alterations are related to unsuccessful treatment response in myofascial TMD patients.

Altered Gut Microbiome Composition and Function in Individuals with Complex Regional Pain Syndrome

BACKGROUND

Complex regional pain syndrome is a chronic pain syndrome typically affecting a limb. It is characterized by severe spontaneous and evoked pain, along with vasomotor, autonomic, and motor signs and symptoms. Although dysregulation in several physiologic systems has been suggested in complex regional pain syndrome (CRPS), including aberrant inflammatory and immune responses, vasomotor dysfunction, and nervous system changes, the pathophysiologic mechanisms underlying the syndrome remain elusive. Effective treatment options are also limited. Previous research has highlighted the role of the gut microbiome in chronic pain, prompting us to investigate the composition and function of the gut microbiome in CRPS.

METHODS

The gut microbiomes of individuals with CRPS to age-, sex-, and ethnicity-matched pain-free control participants were compared using 16S rRNA gene amplification. To minimize environmental confounders, participants were recruited from two geographically independent regions. To explore potential changes in gut bacteria-derived metabolites, targeted metabolomic analysis of feces and plasma was performed. Finally, machine learning algorithms were trained to identify the gut microbiome composition specific to CRPS patients and were tested on a validation cohort.

RESULTS

In this study, differential abundance analysis revealed significant differences in several bacterial taxa when comparing 53 CRPS patients to 52 unrelated controls, including alterations in short-chain fatty acid-metabolizing species. Targeted stool and plasma metabolite analysis confirmed differences in fecal and plasma short-chain fatty acid levels between CRPS patients and controls. Notably, the microbiome composition alone allowed accurate classification of patients and controls in a geographically independent test cohort.

CONCLUSIONS

These findings highlight unique compositional and functional changes in the gut microbiome of individuals with CRPS, thus contributing to the growing body of evidence supporting the role of the gut microbiome in chronic pain syndromes. Furthermore, they pave the way for further studies elucidating the pathophysiology of CRPS and exploring new diagnostic aids and treatment modalities.

Chronic Pain Characteristics and Interference With Daily Activities in Patients Undergoing Hemodialysis: A Cross-Sectional Study

PURPOSE

Few studies have analyzed the characteristics of chronic pain and its functional interference. This study aims to measure the prevalence of pain and assess the intensity, location, treatments used and functional interference in the daily living of patients with chronic pain undergoing hemodialysis treatments in Morocco.

DESIGN

This research has a descriptive cross-sectional design METHODS: A multicenter study was performed in four public hemodialysis centers in Morocco's northern region including 174 patients undergoing hemodialysis. Sociodemographic, chronic pain and interference were evaluated through a structured questionnaire, the Visual Analog Scale and the Brief Pain Inventory.

RESULTS

Descriptive statistics were applied to data analysis. The prevalence of chronic pain was 56.7%, severe in 50.6% of cases and 81.6% experienced continuous pain. The most common pain locations among patients undergoing hemodialysis were the lower limbs 58.6%, back 41.4% and hips 36.4%. Therefore, a high prevalence of severe functional interference of pain has been found in walking 60.34%, general activities 52.87% and work 48.85%. Additionally, analgesics were used by 73.6% of patients, with 46.1% of instances involving frequent use and relief for 32.81%.

CONCLUSIONS

Chronic pain is prevalent, undertreated and localized in the lower limbs, back and hips, leading to severe interference with functional activities.

CLINICAL IMPLICATIONS

This evidence makes professionals aware of their patient's pain and its impact, and consequently, their assessment must be conducted in a primordial and regular manner to improve management. Pain management can be based on pharmacological approaches such as opioids as well as nonpharmacological approaches.

PDGFR-α Mediated the Neuroinflammation and Autophagy via the JAK2/STAT3 Signaling Pathway Contributing to Depression-Like Behaviors in Myofascial Pain Syndrome Rats

Depression often occurs in patients with additional co-morbidities, particularly in cases of chronic pain. Currently, there is a lack of research on the molecular mechanisms of depression under chronic pain conditions and suitable animal models. Due to the contradiction exhibited by platelet-derived growth factor receptor (PDGF/PDGFR) in neuroprotection, further investigation is required. In the present study, we investigated the roles of PDGFR-α in the hippocampus based on rat models of chronic pain (myofascial pain syndrome, MPS) that exhibited depressive phenotypes. The depression-like phenotypes were assessed by the sucrose preference test, forced swimming test, tail suspension test, and the levels of BDNF and 5HT1AR. Electron microscopic analysis and altered expression of autophagy-related proteins revealed reduced autophagy levels in the hippocampus of MPS rats. Phosphorylation PDGFR-α was significantly upregulated in the MPS rat model of depression, as well as the levels of inflammatory factors and p-JAK2/p-STAT3. Treatment with inhibitors of PDGFR-α or JAK2/STAT3 alleviated depressive behaviors, Nissl bodies staining, increased the protein levels of BDNF and 5HT1AR, and decreased the levels of inflammatory factors in MPS rats. Additionally, it restored autophagy levels. These results indicate that PDGFR-α induces neuroinflammation, altered autophagy, and depressive behavior, potentially mediated by the JAK2/STAT3 signaling pathway in MPS rats. PDGFR-α may thus represent a promising therapeutic target for the treatment of this type of depression.

People Living with Chronic Pain Experience a High Prevalence of Decision Regret in Canada: A Pan-Canadian Online Survey

Background(1) To estimate the prevalence of decision regret in chronic pain care, and (2) to identify factors associated with decision regret.DesignWe conducted a pan-Canadian cross-sectional online survey and reported the results following the Checklist for Reporting of Survey Studies guidelines. We recruited a sample of adults experiencing chronic noncancer pain. We used a stratified proportional random sampling based on the population and chronic pain prevalence of each province. We measured decision regret with the Decision Regret Scale (DRS) and decisional needs with the Ottawa Decision Support Framework. We performed descriptive analysis to estimate the prevalence and level of decision regret and multilevel multivariable regression analysis to identify factors associated with regret according to the STRengthening Analytical Thinking for Observational Studies recommendations.ResultsWe surveyed 1,649 people living with chronic pain, and 1,373 reported a most difficult decision from the 10 prespecified ones, enabling the collection of a DRS score. On a scale ranging from 0 to 100 where 1 reflects the presence of decision regret and 25 constitutes important decision regret, the mean DRS score in our sample was 28.8 (s = 19.6). Eighty-four percent of respondents experienced some decision regret and 50% at an important level. We identified 15 factors associated with decision regret, including 4 personal and 9 decision-making characteristics, and 2 consequences of the chosen option. Respondents with low education level and higher decisional conflict experienced more decision regret when the decision was deemed difficult.ConclusionsThis pan-Canadian survey highlighted a high prevalence and level of decision regret associated with difficult decisions for pain care. Decision making in pain care could be enhanced by addressing factors that contribute to decision regret.HighlightsWe conducted an online pan-Canadian survey and collected responses from a wide diversity of people living with chronic pain.More than 84% of respondents experienced decision regret and approximately 50% at an important level.We identified 15 factors associated with decision regret, including 4 personal and 9 decision-making characteristics, and 2 consequences of the chosen option.Our pan-Canadian survey reveals an urgent need of a shared decision-making approach in chronic pain care that can be potentiated by targeting multiple factors associated with decision regret.

Unraveling the role of fear and avoidance behavior in chronic musculoskeletal pain: from theory to physical therapy clinical practice

BACKGROUND

Protective behaviors in the context of pain fostered by fear are helpful in acute traumatic pain to enable a person to protect their body from further injury and promote healing in the short term. However, protective behavior that is ongoing in the absence of tissue damage may contribute to the persistence of disability in people with musculoskeletal pain. Current evidence highlights the importance of addressing pain-related fear, fear of movement-related pain, and avoidance behavior in the management of people with chronic musculoskeletal pain. But, physical therapists find it challenging to make sense of and implement the evidence in their clinical practice. This issue partly stems from the pervasiveness of the biomedical model, which fails to address important psychological factors such as fear of movement-related pain and avoidance behavior and their role in chronic musculoskeletal pain. Despite a wider acceptance of the biopsychosocial model of care, physical therapists lack confidence and guidance on how to implement this model into practice.

OBJECTIVE

The aims of this masterclass are twofold: (1) to describe how the concepts/theory of fear learning can be applied in physical therapy practice for people with chronic musculoskeletal pain, (2) to illustrate the implementation of these concepts in clinical practice using an example of the management of a person with a chronic musculoskeletal pain condition.

DISCUSSION

We discuss how clinicians may identify and target fear of movement-related pain and avoidance behavior in clinical practice, with examples of how to understand and manage individuals with chronic musculoskeletal pain using an associative learning and behavioral framework.

Widespread pain phenotypes impact treatment efficacy results in randomized clinical trials for interstitial cystitis/bladder pain syndrome: a Multidisciplinary Approach to the Study of Chronic Pelvic Pain network study

ABSTRACT

Pain clinical trials are notoriously complex and often inefficient in demonstrating efficacy, even for known efficacious treatments. A major issue is the difficulty in the a priori identification of specific phenotypes to include in the study population. Recent work has identified the extent of widespread pain as an important determinant of the likelihood of response to therapy, but it has not been tested in clinical trials for the treatment of interstitial cystitis/bladder pain syndrome (IC/BPS). We explored this hypothesis using data from 3 previously published trials testing treatments for IC/BPS, which suggested modest benefits but did not meet a priori primary outcome statistical significance criteria. Importantly, these studies also collected symptom questionnaire data that allowed us to retrospectively identify participants with and without widespread pain. Analyzing the treatment by the degree of widespread pain revealed a difference in outcome and statistical significance level for each trial. Participants with predominately local pain (ie, limited widespread pain symptoms) responded to therapy targeting local symptoms, whereas those with widespread pain did not. Alternatively, participants with widespread pain beyond their local pelvic pain responded to more centrally acting treatments. Our results suggest that differentiating patients based on widespread vs more localized pain is a key consideration for designing future clinical trials for conditions with variable pain profiles, such as IC/BPS and potentially other pain-based syndromic disorders.

Effectiveness of pharmacological therapies for fibromyalgia syndrome in adults: an overview of Cochrane Reviews

OBJECTIVES

To summarize and evaluate Cochrane reviews of pharmacological therapies for adults with fibromyalgia syndrome (FMS) pain.

METHODS

Systematic search of Cochrane Database of Systematic Reviews to May 2024. Generic quality assessment used AMSTAR-2 criteria, validity checks of potentially critical factors in evaluation of analgesic efficacy and assessment of susceptibility of results to publication bias. Pain outcomes were participant-reported pain relief of ≥30% or ≥50%, or PGIC much or very much improved.

RESULTS

Twenty-one reviews (87 trials, 17 631 patients) were included. All rated moderate (15) or high-quality (6) using AMSTAR-2 and at least seven of eight critical pain criteria were met by 13 of 21 reviews. Diagnosis of FMS used recognized criteria. Seven reviews found no trials (carbamazepine, clonazepam, lamotrigine, phenytoin, oxycodone, topiramate or valproate), seven had limited and inadequate data (antipsychotics, cannabinoids, combination therapy, gabapentin, lacosamide, monoamine oxidase inhibitors, NSAIDs) and two were subject to publication bias (amitriptyline, SSRI). Mirtazapine had moderate evidence of no effect. Duloxetine, milnacipran and pregabalin had moderate/good evidence of substantial pain relief for 4-12 weeks in around 1 in 10 adults with moderate or severe FMS pain, without evidence of efficacy beyond six months. Serious adverse events were no more common than with placebo. There was no evidence about who might benefit or experience adverse events. There was no substantial efficacy evidence for other medicines.

CONCLUSIONS

Duloxetine, milnacipran and pregabalin had good evidence that about 1 person in 10 with moderate or severe pain experienced pain intensity reduction by at least 50%.

Is poor dietary quality in adolescence a risk factor for painful temporomandibular disorders and headaches in young adulthood? A prospective study in the Danish National Birth Cohort

OBJECTIVE

To investigate the association between adolescents' dietary quality and the presence of painful temporomandibular disorder (p-TMD) and headaches in young adulthood.

BACKGROUND

P-TMD is a common orofacial pain condition often associated with headaches and discomfort. Some studies have shown that dietary behaviors can impact chronic musculoskeletal pain. Although various factors such as sex, age, psychosocial aspects, and pain sensitivity contribute to p-TMD, the role of nutrition remains unclear.

METHODS

The dietary quality of 32,247 singletons from the Danish National Birth Cohort (DNBC) at age 14 was assessed using the Healthy Eating Index (HEI) encompassing eight domains. Among these, 11,982 (37.1%) individuals completed the TMD pain screener and headache-related queries at age 18 and above. HEI and dietary domains were analyzed as potential risk factors for p-TMD and headaches.

RESULTS

P-TMD was present in 3163 of the 11,982 members of the study population. HEI scores were divided into quartiles, with quartile four indicating the highest dietary quality. Quartile four showed a higher odds ratio (OR) for p-TMD than quartile one (OR = 1.14 [95% confidence interval (CI), 1.01-1.29]), but the significance was lost after adjustment for confounders (adjusted OR [aOR] = 1.12 [95% CI, 0.97-1.30]). Overall dietary quality was not significantly associated with headaches. However, specific dietary quality domains, such as dietary fibers (aOR = 0.97 [95% CI, 0.95-0.99]), fish (aOR = 0.98 [95% CI, 0.97-1.00]), sodium (aOR = 1.03 [95% CI, 1.01-1.06]), and added sugar (aOR = 0.97 [95% CI, 0.95-0.99]) were associated with headaches but not with p-TMD after adjustment.

CONCLUSION

Overall adolescent dietary quality did not significantly associate with p-TMD or headaches in young adulthood after adjusting for confounders. However, specific dietary domains exhibited weak but statistically significant associations with headaches. These findings underscore the interplay between diet and pain, calling for further research to unveil the underlying pathophysiological mechanisms connecting lifestyle, p-TMD, and headaches.

Harmonizing neuropathic pain research: outcomes of the London consensus meeting on peripheral tissue studies

ABSTRACT

Neuropathic pain remains difficult to treat, with drug development hampered by an incomplete understanding of the pathogenesis of the condition, as well as a lack of biomarkers. The problem is compounded by the scarcity of relevant human peripheral tissues, including skin, nerves, and dorsal root ganglia. Efforts to obtain such samples are accelerating, increasing the need for standardisation across laboratories. In this white paper, we report on a consensus meeting attended by neuropathic pain experts, designed to accelerate protocol alignment and harmonization of studies involving relevant peripheral tissues. The meeting was held in London in March 2024 and attended by 28 networking partners, including industry and patient representatives. We achieved consensus on minimal recommended phenotyping, harmonised wet laboratory protocols, statistical design, reporting, and data sharing. Here, we also share a variety of relevant standard operating procedures as supplementary protocols. We envision that our recommendations will help unify human tissue research in the field and accelerate our understanding of how abnormal interactions between sensory neurons and their local peripheral environment contribute towards neuropathic pain.

Do Psychological Factors Explain the Persistence of Symptoms in Individuals With Rotator Cuff-related Shoulder Pain? A Prospective Cohort Study

OBJECTIVE

To determine whether psychosocial factors, such as resilience, perceived stress, catastrophizing, anxiety, depression, pain self-efficacy, and social support, explain the persistence of pain and disability in individuals with rotator cuff-related shoulder pain (RCRSP) following an education program.

METHODS

One hundred forty-three individuals with persistent RCRSP were included in this prospective cohort study. At baseline, participants completed self-reported questionnaires related to pain, disability, and psychosocial constructs, including resilience, stress, catastrophizing, anxiety and depressive symptoms, pain self-efficacy, and social support. Thereafter, participants took part in an educational program aimed at promoting self-management of RCRSP that included 2 meetings with a physiotherapist. After 12 and 24 weeks, participants filled out pain and disability questionnaires and, based on their scores, were classified as having persistent shoulder pain or as recovered.

RESULTS

A univariable modified Poisson regression showed that higher perceived stress (RR adjusted : 1.02; 95% CI: 1.01-1.04), catastrophizing (RR adjusted : 1.01; 95% CI: 1.01-1.02), symptoms of depression (RR adjusted : 1.03; 95% CI: 1.01-1.06) and anxiety (RR adjusted : 1.03; 95% CI: 1.01-1.06), along with lower resilience (RR adjusted : 0.90; 95% CI: 0.81-1.00), were associated with ongoing RCRSP at 12 weeks. In addition, reduced pain self-efficacy was associated with persistent pain at both 12 weeks (RR adjusted : 0.98; 95% CI: 0.97-0.99) and 24 weeks (RR adjusted : 0.99; 95% CI: 0.98-1.00). Multivariable regression indicated that only pain self-efficacy served as a protective factor against persistent RCRSP (RR adjusted : 0.98; 95% CI: 0.97-0.99).

DISCUSSION

This study sheds light on the impact of psychosocial factors on persistent RCRSP, underscoring the importance of positive beliefs in pain management. Importantly, pain self-efficacy emerges as a key factor in recovery.

Personalised decision support in the management of patients with musculoskeletal pain in primary physiotherapy care: a cluster randomised controlled trial (the SupportPrim project)

ABSTRACT

We developed the SupportPrim PT clinical decision support system (CDSS) using the artificial intelligence method case-based reasoning to support personalised musculoskeletal pain management. The aim of this study was to evaluate the effectiveness of the CDSS for patients in physiotherapy practice. A cluster randomised controlled trial was conducted in primary care in Norway. We randomised 44 physiotherapists to (1) use the CDSS alongside usual care or (2) usual care alone. The CDSS provided personalised treatment recommendations based on a case base of 105 patients with positive outcomes. During the trial, the case-based reasoning system did not have an active learning capability; therefore, the case base size remained the same throughout the study. We included 724 patients presenting with neck, shoulder, back, hip, knee, or complex pain (CDSS; n = 358, usual care; n = 366). Primary outcomes were assessed with multilevel logistic regression using self-reported Global Perceived Effect (GPE) and Patient-Specific Functional Scale (PSFS). At 12 weeks, 165/298 (55.4%) patients in the intervention group and 176/321 (54.8%) in the control group reported improvement in GPE (odds ratio, 1.18; confidence interval, 0.50-2.78). For PSFS, 173/290 (59.7%) patients in the intervention group and 218/310 (70.3%) in the control group reported clinically important improvement in function (odds ratio, 0.41; confidence interval, 0.20-0.85). No significant between-group differences were found for GPE. For PSFS, there was a significant difference favouring the control group, but this was less than the prespecified difference of 15%. We identified several study limitations and recommend further investigation into artificial intelligence applications for managing musculoskeletal pain.

Exploring the emotional impact of pain on children and adolescents: A poetic meta-ethnography

Pain in early life can go unreported and untreated. We use poems to portray findings from a systematic review of qualitative research. The overall aim of the review was to distil essential experiences across pain conditions and contexts. This report, focusing on the emotional impact of pain, is one of a series of three analyses from one systematic review of qualitative research. We used meta-ethnography to synthesise research. We identified studies in English that explored acute and/or chronic child and/or adolescent pain experience. Findings were distilled into themes and poems co-created in English and Spanish. We included 189 reports (177 unique studies) incorporating 5875 people (at least 3484 reported as female). Most studies (93%) included participants aged 11-20 years (range 2-38). The studies explored acute (24% studies), chronic (75%), and acute/chronic (1%). We report seven themes: (1) Pain can be hard to bear; (2) Pain is scary; (3) Pain is constantly at the back of my mind: (4) Pain makes me feel like I am outside alone; (5) Pain makes school a hard fit; (6) Pain can hurt me deep inside; (7) Pain has changed me. Our themes highlight the emotional impact of pain across conditions and contexts. Art and science are both integral to leaps in understanding. The contribution of the Arts is their unique ability to reach audiences on an affective level, giving the potential to underpin compassionate care and policy. We invite readers to utilise these poems to start a conversation about young people's pain experiences. This systematic review was registered on the PROSPERO database (CRD42023429027). Ethical permissions are not required for an evidence synthesis. PERSPECTIVE: The voices of young people in pain are not always heard. This article presents themes, in poetic form, from a synthesis of 189 qualitative studies. Science and art are integral to leaps in understanding and inclusive arts-based research methods have the potential to underpin compassionate pain care for young people.

Predicting placebo analgesia responses in clinical trials: where to look next? A meta-analysis of individual patient data

ABSTRACT

Estimating the magnitude of placebo responses across pharmacological and nonpharmacological trials is important for understanding their influence on trial outcomes. Yet, the extent to which more intense placebo interventions like sham acupuncture yield larger analgesic responses than placebo pills, and the factors predicting these responses, remain unclear. This meta-analysis investigated the magnitude and predictors of placebo analgesia responses in pharmacological vs acupuncture trials. Analyses included individual patient data from the placebo arm of 11 randomized controlled trials (RCTs): 9 pharmacological RCTs using placebo pills (N = 2021) and 2 acupuncture RCTs using sham acupuncture (N = 747). All trials were conducted in patients with chronic nociceptive pain (osteoarthritis, N = 2068; low back pain, N = 700). The placebo response was calculated as the change in pain intensity (0-100) between baseline and week 12. A random effects model demonstrated that placebo pills and patients with osteoarthritis exhibited smaller placebo responses than sham acupuncture and patients with low back pain (both P < 0.001, marginal effects). A mixed effects model showed that route of administration interacted significantly with baseline pain, premature termination, and the presence of adverse events. Together, predictors explained 20% to 25% of the individual variance in placebo responses, whereas 75% to 80% remained unaccounted for. In summary, sham acupuncture accounted for slightly larger placebo responses than placebo pills. Since basic trial and patient parameters explained only a small portion of this variability, we might need to start considering the patient's perception of the treatment-including cognition and emotions-to better predict placebo analgesia responses.

Individuals with chronic low back pain show impaired adaptations of lumbar extensor muscle reflex amplitude during unexpected perturbations

PURPOSE

This study investigated the adaptability of trunk muscle responses to a series of unexpected external perturbations in patients with chronic low back pain (LBP).

METHODS

Thirty-seven adult participants, including 19 without LBP (control group) and 18 with chronic LBP, were submitted to 15 repetitions of trunk perturbations applied in a posterior-to-anterior direction, inducing trunk flexion. High-density surface electromyography (HDsEMG) was used to analyze lumbar muscle reflex amplitude. A two-way repeated measures ANOVA (2 × 2) was conducted to compare group differences and the effect of trial repetition over time (first five trials vs. last five trials of perturbations).

RESULTS

Significant interaction effects were found on both sides (Left: p = 0.038; Right: p = 0.007). Post hoc comparisons revealed a decrease in response amplitude only in the control group between the first and last five perturbations, with reductions of 5.0% on the left side (p = 0.026, Bonferroni corrected) and 5.7% on the right side (p = 0.030, Bonferroni corrected). In contrast, individuals with chronic LBP showed no significant adaptation through repetition in the reflex response amplitude of the lumbar extensor muscles (post hoc both sides: p > 0.05).

CONCLUSION

Individuals with chronic LBP fail to adapt reflex amplitudes to repeated perturbations, possibly due to impaired proprioception, reduced motor variability and neuroplastic changes observed in individuals with chronic LBP. These changes might limit their ability to optimize responses to repeated perturbations, potentially compromising spinal stability and increasing functional cost.

TRPV1-target drugs for the treatment of orofacial pain

Orofacial pain, encompassing sensory and emotional discomfort in the facial and oral regions, is a multifaceted condition that significantly impacts patients' quality of life. This review focuses on the role of Transient Receptor Potential Vanilloid 1 (TRPV1) channels in modulating orofacial pain and new ligands targeting this receptor. TRPV1 channels act as key mediators of nociception, responding to stimuli such as temperature, pH changes, and capsaicin molecules. Recent advancements in TRPV1-targeted therapeutics, including natural, synthetic, and protein-based molecules, offer promising strategies for pain management. This review analyzed studies related to TRPV1-mediated pain inhibition, including seven clinical trials and preclinical investigations. The compounds studied in these works demonstrated pain relief, although adverse effects were reported. TRPV1-targeted molecules represent a novel avenue for developing innovative pharmacological interventions, addressing the limitations of current therapies, and improving patient outcomes in managing orofacial pain.

Clinical Benefits of Ibuprofen Arginine: A Narrative Review

Ibuprofen arginine (IBA) combines well-established analgesic and anti-inflammatory properties with enhanced pharmacokinetics. The addition of arginine significantly improves solubility and absorption, leading to a faster onset of action compared to conventional ibuprofen. Clinical studies consistently demonstrate that IBA achieves meaningful pain relief within a shorter timeframe while maintaining a favorable safety profile. IBA's rapid action is particularly valuable in managing acute exacerbations of chronic pain and preventing central sensitization, thus improving patient comfort, adherence, and overall quality of life. By addressing both the inflammatory and nociceptive components of pain, IBA offers an effective and well-tolerated alternative in multimodal pain management strategies. This review explores the clinical benefits of IBA in pain management among various clinical settings.

Development of a Longitudinal Model for Disability Prediction in Older Adults in China: Analysis of CHARLS Data (2015-2020)

Background

Disability profoundly affects older adults' quality of life and imposes considerable burdens on health care systems in China's aging society. Timely predictive models are essential for early intervention.

Objective

We aimed to build effective predictive models of disability for early intervention and management in older adults in China, integrating physical, cognitive, physiological, and psychological factors.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS), spanning from 2015 to 2020 and involving 2450 older individuals initially in good health, were analyzed. The dataset was randomly divided into a training set with 70% data and a testing set with 30% data. LASSO regression with 10-fold cross-validation identified key predictors, which were then used to develop an Extreme Gradient Boosting (XGBoost) model. Model performance was evaluated using receiever operating characteristic curves, calibration curves, and clinical decision and impact curves. Variable contributions were interpreted using SHapley Additive exPlanations (SHAP) values.

Results

LASSO regression was used to evaluate 36 potential predictors, resulting in a model incorporating 9 key variables: age, hand grip strength, standing balance, the 5-repetition chair stand test (CS-5), pain, depression, cognition, respiratory function, and comorbidities. The XGBoost model demonstrated an area under the curve of 0.846 (95% CI 0.825-0.866) for the training set and 0.698 (95% CI 0.654-0.743) for the testing set. Calibration curves demonstrated reliable predictive accuracy, with mean absolute errors of 0.001 and 0.011 for the training and testing sets, respectively. Clinical decision and impact curves demonstrated significant utility across risk thresholds. SHAP analysis identified pain, respiratory function, and age as top predictors, highlighting their substantial roles in disability risk. Hand grip and the CS-5 also significantly influenced the model. A web-based application was developed for personalized risk assessment and decision-making.

Conclusions

A reliable predictive model for 5-year disability risk in Chinese older adults was developed and validated. This model enables the identification of high-risk individuals, supports early interventions, and optimizes resource allocation. Future efforts will focus on updating the model with new CHARLS data and validating it with external datasets.

The Added Value of Digital Body Chart Pain Surface Assessment as an Objective Biomarker: Multicohort Study

BACKGROUND

Although it has been well-documented that pain intensity alone is not sufficient to assess chronic pain, the objective pain surface encapsulated in a digital tool might present a major interest in the objective assessment of pain.

OBJECTIVE

This study aims to determine the potential added value of pain surface measurement by determining the correlation between pain surface and pain intensity in chronic pain patients.

METHODS

Two databases from observational prospective and retrospective longitudinal studies including patients with chronic pain were used in this research. Pain intensity was assessed by the Numeric Pain Rating Scale. Pain surface (cm²) and pain typology (neuropathic vs mechanical components) were measured by a specific pain mapping digital tool (PRISMap, Poitiers University Hospital). Patients were asked to draw their pain surface on a computerized tactile interface in a predetermined body (adapted from the patient's BMI). A color code was used to represent pain intensity (very intense, intense, moderate, and low). Simple linear regression was used to assess the proportion of variance in pain surface explained by pain intensity.

RESULTS

The final analysis included 637 patients with chronic pain. The percentage of variance of the pain surface explained by pain intensity was 1.24% (R²=0.0124; 95% CI 0.11%-6.3%). In addition, 424 (66.6%) patients used more than 1 intensity or color, among whom 218 (34.2%) used 2 intensities or colors, 155 (24.3%) used 3 intensities or colors, and 51 (8%) used 4 intensities or colors.

CONCLUSIONS

This study showed that pain intensity and pain surface provide complementary and distinct information that would help to improve pain assessment. Two-thirds of the cohort used 2 or more intensities to describe their pain. Combining pain intensity and pain surface should be strongly considered as a means of improving daily practice assessment of patients with chronic pain in primary and secondary care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02964130; https://clinicaltrials.gov/study/NCT02964130?term=PREDIBACK&rank=2.

Correlation between attention deficit/hyperactivity disorder and chronic pain: a survey of adults in Japan

This cross-sectional epidemiological internet survey assessed whether attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) symptoms are associated with pain chronicity and intensity and explored the relationship between developmental disorder symptoms and pain. Participants were 4028 adults aged 20-64 years who experienced pain, assessed using an 11-point numerical rating scale (NRS), in any body part in the previous 4 weeks. ADHD and ASD symptoms were assessed using the Adult ADHD Self-Report Scale (ASRS) and autism spectrum quotient, respectively. Problems with mental health (PMH) were assessed using the shortened Profile of Mood States. Pathway analyses were performed to examine the association between ADHD symptoms and pain. The chronic pain symptoms (CP) group (N = 1465) scored higher than the non-CP group (N = 2563) for all ASRS variables. ASRS positivity was associated with CP symptoms and increased with increasing NRS score; the CP group showed particularly high positivity (38.3%) with extreme pain. ADHD symptoms were more strongly associated with CP symptoms and intensity than was PMH (0.26 vs. 0.09). ADHD symptoms, but not ASD symptoms, were associated with CP symptoms. ADHD medications reportedly improve coexisting CP; therefore, ADHD screening and treatment may be important for patients with CP, especially those with extreme pain.

Depression and its influencing factors among older adults with chronic pain in China: an empirical analysis based on CHARLS data

Background

China's aging problem is intensifying, the older adult not only face a variety of chronic physical diseases and pain, but also have higher levels of depression than other age groups. This study explores the related factors of depression in older adults with chronic pain in China and provide evidence and reference for the formulation of intervention policies and measures.

Methods

Using the data of the fifth wave of national survey conducted by the China Health and Retirement Longitudinal Study (CHARLS) in 2020, a total of 10,581 older adults with chronic pain were selected as research objects, and their depression status was measured by the Depression Scale (CES-D). Chi-square test and multiple logistic regression were used to analyze the main factors affecting depression in older adults with chronic pain.

Results

The results of multivariate logistic regression analysis showed: gender (female: OR = 1.28, 95%CI = 1.16-1.41), age (≥75 years old: OR = 0.49, 95%CI = 0.42-0.56), spouse/partner living together (no: OR = 1.19, 95%CI = 1.06-1.32), place of residence (rural: OR = 1.19, 95%CI = 1.06-1.32), education level (High school and above: OR = 1.19, 95%CI = 1.06-1.32); satisfaction with child relationship (satisfaction: OR = 0.22, 95%CI = 0.18-0.28), smoking (no: OR = 0.60, 95%CI = 0.41-0.86), Internet use in the past month (Yes: OR = 0.77, 95%CI = 0.68-0.86), nap duration (1 ~ <2 h: OR = 0.75, 95%CI = 0.66-0.85; ≥2 h: OR = 0.75, 95%CI = 0.66-0.85), night sleep duration (6 ~ <8 h: OR = 0.75, 95%CI = 0.66-0.85; ≥8 h: OR = 0.56, 95%CI = 0.49-0.63), BADL damaged (Yes: OR = 1.45, 95%CI = 1.31-1.62), IADL damaged (Yes: OR = 1.31, 95%CI = 1.17-1.45), received outpatient services in the past month (Yes: OR = 1.18, 95%CI = 1.06-1.31), pain (Quite a Bit/Very: OR = 1.41, 95%CI = 1.26-1.58), number of body parts that feeling pain (1 ~ 3: OR = 1.42, 95%CI = 1.27-1.60; 4-6: OR = 1.76, 95%CI = 1.51-2.04; 7 ~ 9: OR = 2.21, 95%CI = 1.82-2.67; ≥10: OR = 2.63, 95%CI = 2.15-3.22) are the influencing factors of depressive symptoms in older adults with chronic pain (p < 0.05).

Conclusion

The incidence of depressive symptoms in older adults with chronic pain is 31.7%, and their depression status is affected by various factors. Medical and health institutions and policy makers should pay attention to the mental health of these older adults, and take targeted measures to improve health education, disease treatment, pain management, sleep improvement, family support, and other aspects according to their characteristics.

Lived and care experiences of young people with chronic musculoskeletal pain and mental health conditions: a systematic review with qualitative evidence synthesis

ABSTRACT

Chronic musculoskeletal pain (CMP) and coexisting mental health conditions impact young people; however, little is known about their lived and care experiences. In a prospectively registered systematic review with qualitative evidence synthesis (PROSPERO: CRD42022369914), we explored the following: (1) lived physical, psychological, and social experiences; and (2) care experiences/preferences of young people living with CMP and mental health conditions. Inclusion criteria: studies using qualitative methods; participants aged 16 to 24 years with CMP and coexisting mental health condition(s); phenomenon explored included lived and/or care experiences. Seven databases were searched (inception to 19-May-2024), study quality was assessed, data were extracted and analysed thematically, and GRADE-CERQual was used to assess confidence in findings. Twenty-two studies (23 reports) were included (>239 participants, 82% women). Lived experiences yielded 4 themes (9 findings): 2-way relationship between CMP and mental health (2 findings, low to moderate confidence); psychosocial implications of CMP (3 findings, very low-moderate confidence); uncertainty about future (2 findings, low-moderate confidence); coping with CMP and mental health conditions (2 findings, low-moderate confidence). Care experiences/preferences yielded 3 themes (8 findings): navigating healthcare systems (2 findings, moderate confidence); receiving appropriate care (3 findings, very low-moderate confidence); point-of-care experiences and care preferences (3 findings, very low-moderate confidence). Chronic musculoskeletal pain and mental health conditions are interconnected, significantly impacting young people's lives, identities, and socialisation, yet services for CMP and mental health are often inadequate and poorly integrated. The mechanisms and interplay of CMP and mental health require deeper exploration, including how young people may be better supported with personalised, holistic, developmentally and/or life-stage-appropriate integrated care.

The prevalence of chronic pain and its impact on activities of daily living disability and depressive symptoms according to multiple definitions in a Japanese population: the Hisayama study

Objectives

This study aimed to compare the prevalence of chronic pain using various definitions from previous studies and to determine the optimal definition for detecting chronic pain associated with physical and emotional dysfunction in a general Japanese population.

Methods

A total of 2700 community-dwelling Japanese residents aged ≥40 years were assessed for chronic pain and its components of duration, frequency, and intensity. The activities of daily living (ADL) disability and depressive symptoms of participants were also evaluated using the modified Lankin Scale and Patient Health Questionnaire-9. The odds ratios and the population attributable fractions (PAFs) for ADL disability and depressive symptoms were estimated using a logistic regression model.

Results

The prevalence of chronic pain varied greatly by definition, ranging from 13% for pain defined as pain duration ≥3 months, pain frequency ≥ twice a week, and pain intensity of ≥50 mm by a visual analogue scale (VAS) to 48% for a simple definition of pain duration ≥3 months. The PAFs for ADL disability and depressive symptoms were relatively high at 33% in participants with pain duration of ≥6 months and 30% in those with pain frequency of ≥twice a week, while the VAS ≥50 mm group had a low PAF of 12%.

Conclusion

For screening people with chronic pain and ADL disability or depressive symptoms, the criteria of pain duration and pain frequency yielded essentially identical results, while the criterion of pain intensity risked overlooking individuals with chronic pain and these associated symptoms.

Understanding the individual's transition from acute to chronic disabling pain: Opportunities for improved care

When acute pain persists, it is said to become chronic after 3 months. Considerable interest has focused on why acute pain appears to transition to chronic pain in some cases, but not all, especially when it becomes disabling. We examine our current understanding of the processes involved in the progression from an acute injury to disabling chronic pain. Rather than viewing this progression as a time dependent transition with specific static risk factors, we consider whether it might be more helpful to understand this evolution in terms of unique individual pathways. While brief self-report screening questionnaires assessing risk factors may enable us to stratify patients into risk levels, they do not provide information on the unique context and factors contributing to the disabling pain for each person. It is proposed that a 2-step process combining screening and individual assessment of those at high risk will enhance the prospect of both early identification and individually relevant interventions before more lasting changes emerge. Rather than being concerned with arbitrary time limits, it is argued that by aiming to understand the unique developmental pathway for those individuals identified as high risk, early, preventive interventions will be both viable and effective. Even so, there are barriers to the implementation of early assessment and matched treatments, and these remain a challenge for future research.

Chronic health conditions and disability are prevalent among community users of a digital mental health service: a scoping survey

Objectives: Digital interventions can offer accessible and scalable treatment for chronic conditions, though often focus separately on physical or mental health. People accessing digital health services may live with multiple conditions or experience overlapping symptoms. This study aimed to describe the breadth and characteristics of chronic health conditions and self-reported disability among routine users of a digital mental health service, and to examine related motivations to engage with digital mental health interventions.

Methods: A cross-sectional survey of adults registered with a digital mental health service in the Australian community (THIS WAY UP) was conducted. Participant demography, chronic health conditions, self-reported disability and motivations for accessing digital treatment were collected and analyzed descriptively.

Results: 366 participants responded (77% female, mean age 50 ± 15 years). 71.6% of participants (242/338) reported ≥1 chronic health condition and one-third reported multimorbidity (112/338, 33.1%). Chronic pain, musculoskeletal and connective tissue disorders were most common. 26.9% of respondents (90/334) reported a disability, most commonly physical disabilities. 95% of those with chronic conditions reported negative mental health effects and 46% reported heightened interest in digital mental health treatments because of their condition. Primary motivations for digital service use were receiving a recommendation from a health professional and service accessibility.

Discussion: People who access digital mental health services in routine care report high rates of heterogenous chronic illness and related disability. There is interest in accessible digital treatments to support mental health at scale among people who live with varied chronic conditions and disabilities.

Pain Self-Management in Individuals With Chronic Musculoskeletal Pain During Lebanon's Overlapping Crises

OBJECTIVES

With Lebanon facing multiple crises simultaneously, it is important to understand how Lebanese adults with chronic musculoskeletal pain (CMP) are self-managing their pain amidst challenging circumstances. This study aimed to describe the pain self-management strategies Lebanese adults with CMP are using, as measured by the Arthritis Pain Self-Management Inventory (APSI), and to determine how helpful they perceive these strategies to be for pain relief. A secondary aim was to translate, culturally adapt, and validate the APSI in Lebanese adults with CMP.

METHODS

A descriptive design was used and a convenience sample of 154 Lebanese adults with CMP completed the Arabic version of the APSI and self-report measures of pain intensity and sociodemographic and clinical characteristics.

RESULTS

The APSI demonstrated acceptable content and cultural validity in Lebanese adults with CMP. Self-directed arthritis education was the strategy used by the largest number of participants, although it was perceived as the second least helpful for pain relief. The second and third most common strategies used were rest/relaxation, warm baths, and maintaining a healthy weight. The most helpful strategy was maintaining a healthy weight, followed by watching religious television, music therapy, and the use of braces or splints.

CONCLUSIONS

Lebanese adults with CMP should actively participate in their pain management plan and be educated on the various strategies they could use to effectively self-manage their pain.

A systematic review of social functioning and peer relationships in adolescents with chronic pain

OBJECTIVE

There is a need for a systematic review on social functioning and peer relationships among adolescents with chronic pain (ACP) given the high prevalence of chronic pain in adolescence and integral role of peer relationships in adolescent development. This review aims to examine the methods used to evaluate social functioning, the types and extent of peer relationship difficulties, and pain characteristics and sociodemographic factors related to social functioning in ACP.

METHODS

A systematic literature search of PubMed, PsycINFO, CINAHL, Web of Science, and Cochrane databases was performed. Included studies were written in English, presented original, quantitative, peer-reviewed research, had a primary focus on social functioning or peer relationships in ACP, and included study participants between the ages of 10 and 18 years. The review was registered in PROSPERO (No. CRD42022364870).

RESULTS

Twenty-eight articles were included in the review. All studies used self-, parent-, or peer-report questionnaires to evaluate social functioning. Most (89%) of the studies were cross-sectional. Findings suggest that ACP experience social difficulties frequently characterized by loneliness, social anxiety, withdrawal, and peer victimization. Studies examining the associations between social functioning and sociodemographic variables, pain location, and pain-related characteristics yielded mixed findings. Study quality was mixed, with 57.14% rated as "good."

CONCLUSIONS

Findings from this review emphasize the increased risk of reduced social connectedness and the complexity of underlying mechanisms associated with poorer social functioning among ACP. Additional research utilizing longitudinal methodologies is needed to understand potential moderators and directionality of associations between chronic pain and social functioning.

Chronic pain in European adult populations: a systematic review of prevalence and associated clinical features

ABSTRACT

Chronic pain (CP) is a multifaceted and severely disabling persistent condition that affects individuals worldwide. A synthesis of epidemiological data is still lacking. The present systematic review aims at presenting point, period, and lifetime prevalence estimates of CP in the European adult population, as well as relevant features associated with it. Following PRISMA guidelines, a systematic search in PubMed, Web of Science, Embase, and Cochrane library was run from inception to May 2024, resulting in 39,832 hits. Among those, 132 full-text articles were assessed, and 23 studies comprising 862,013 participants with CP were included. The Joanna Biggs Institutes' Critical Appraisal Checklist for Studies Reporting Prevalence Data (JBI) was used for quality assessment. Findings showed a point prevalence ranging from 12% to 48%, a 6-month prevalence of 17.5% to 49.8%, a 12-month prevalence ranging from 8.1% to 44.6%, and a lifetime prevalence ranging from 12.7% to 33.7% independently from sex. Sociodemographic factors (eg, female sex, higher age, no partnership, lower education, unemployment) and clinical features (eg, medical diseases, mental disorders and burdens, healthcare utilization, functional impairment) were identified as being associated with CP. The variability in prevalence estimates can be reduced by applying consistent diagnostic criteria (eg, ICD-11) and by using standardized assessment tools (eg, scales, clinical interview). The high prevalence and the characteristics of the associated features support the need for adequate, multicomponent care paths to manage CP based on a comprehensive biopsychosocial model.

Pressure pain sensitivity is independent of structural pathology in patients with subacromial pain syndrome: a cross-sectional analysis

OBJECTIVE

To compare localized (primary) and widespread (secondary) hyperalgesia through the measurement of the pressure pain threshold (PPT) of patients with normal imaging findings, rotator cuff tear, or other pathologies.

DESIGN

This was a cross-sectional design with data collected at a single time point.

SETTING

This study was performed at 2 large, urban, academic medical centers.

SUBJECTS

The included participants had had chronic subacromial pain syndrome for 3 months or longer. Each participant was categorized into 1 of 3 imaging groups: normal imaging, rotator cuff tear, or other structural pathology.

METHODS

Primary hyperalgesia was assessed with PPT at the midsection of the painful shoulder's lateral deltoid. Secondary hyperalgesia was assessed with PPT at the contralateral tibialis anterior muscle (TA). Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were performed for each objective. ANCOVA covariates included age, sex, education level, and pain duration.

RESULTS

The 103 participants included 55 males and had a median age of 55 years, a median pain duration of 14.0 months, and a median composite Shoulder Pain and Disability Index (SPADI) score of 43.1%. The ANCOVA for primary hyperalgesia showed no significant difference in square-root-adjusted deltoid PPT among imaging groups (F = 1.04, P = .3589). The ANCOVA for secondary hyperalgesia showed no significant difference in log-adjusted TA PPT among imaging groups (F = 0.24, P = .7900).

CONCLUSIONS

No significant difference was observed in the analysis of ipsilateral deltoid or contralateral TA PPT among patients with differing structural shoulder pathologies. These findings suggest that the 3 types of structural shoulder abnormalities we examined are not significantly associated with differences in one measure of hyperalgesia.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT03752619.

Chronic musculoskeletal pain and its association with cognitive function and sarcopenia in older adults: Characterization and change over three months

Pain, cognitive impairment, and sarcopenia share common risk factors and neurophysiological processes, but studies investigating cognition and sarcopenia in older adults with pain are scarce. This study's main aim was to compare cognition and sarcopenia between older adults with and without chronic pain. A secondary aim was to investigate predictors of cognition and sarcopenia at baseline and 3 months while adjusting for confounders. Participants (67 older adults with pain and 67 asymptomatic older adults) were assessed for sociodemographic and clinical information, pain (number of painful body sites - body chart, pain phenotype - PainDETECT, severity and disability - BPI, pain catastrophizing - PCS, and kinesiophobia - Tampa Scale), cognition (MoCA), sarcopenia (risk of sarcopenia - SARC-F, hand grip strength, and calf circumference) and physical activity (RAPA) at baseline and 3 months after. Older adults with and without pain did not differ in cognition (Mean (95% CI): Pain = 21.47 (20.60; 22.34); Asymptomatic = 21.75 (20.89; 22.61)), but older adults with pain had greater signs of sarcopenia than asymptomatic older adults, including higher risk of sarcopenia (Mean (95%CI): Pain=2.89 (2.41; 3.37); Asymptomatic=0.50 (0.32; 0.68)) and lower hand grip strength (Pain=24.01 (21.74; 26.29); Asymptomatic=27.98 (25.80; 30.16)). No between-group differences were found for calf circumference (Pain=35.03 (34.26; 35.79); Asymptomatic=34.55 (33.86; 35.24)). Pain phenotype (baseline) and kinesiophobia (3 months) contributed to poorer cognition. Kinesiophobia and catastrophizing (baseline), and pain severity (3 months) contributed to sarcopenia. Despite no differences in cognition between older adults with and without pain, pain-related variables contributed to explaining sarcopenia and cognition. PERSPECTIVE: This study compared cognition and sarcopenia between older adults with and without pain and explored the association between pain, cognition, and sarcopenia. Groups were similar for cognition, but older adults with pain showed higher signs of sarcopenia. Kinesiophobia and pain severity partially explained cognition and sarcopenia among those with pain.

Delayed onset muscle soreness effect on spinal stiffness and flexion-relaxation phenomenon of the lumbar spine

This study aims to explore how Delayed Onset Muscle Soreness (DOMS) can induce changes in lumbar erector spinae neuromuscular activity, trunk kinematics and lumbar spine stiffness, and how DOMS can be confirmed as an experimental pain model for studying LBP mechanisms. Seventeen adult participants were asked to perform four sets of 25 repetitions of trunk flexion and extension. During these tasks, trunk muscle activity, spinal stiffness and kinematics were assessed. Our results suggest that in the presence of DOMS, significant increases in lumbar spine stiffness whereas only limited changes in flexion relaxation phenomenon parameters are observed.

Modeling Masticatory Myalgia to Headache-like Referred Pain Triggers Local Gene Plasticity at Referred Pain Sites

Patients with myofascial pain in the head and neck area report widespread and referred pain, including headache. Existing preclinical models fail to replicate this clinical phenotype; therefore, we aimed to develop animal models mimicking referred pain phenomenon and investigate whether referred pain leads to gene plasticity at the referred sites. We modeled masticatory myalgia by stimulation of either the masseter (MM) or temporal muscle (TM) in mice. MM and TM were stimulated with a single high-dose injection of Collagenase-type II (Col), repetitive low-dose Col injections, repetitive gentle MM stimulation, or single or repetitive forceful mouth opening. Referred pain was assessed by measuring mechanical hypersensitivity in the periorbital area (representing headache-like behavior) and another masticatory muscle. Stimulation of the MM, whether through single or repetitive Col injections or mouth opening, produced inconsistent, short-lasting (1-2 days) headache-like behavior in both males and females. In contrast, stimulation of the TM, using different paradigms, triggered mechanical hypersensitivity in both the MM and the periorbital area. Referred headache-like behavior lasted longer in females compared to males, while referred myalgia in the MM was pronouncer in males. The referred pain in the MM and periorbital areas triggered by TM stimulation was associated with significant gene plasticity in the MM and dura mater. Transcriptional changes in the MM following Col injection into the TM resembled those observed after direct MM injections. Presented data imply that referred pain modeled by TM stimulation could be accounted by nociceptive signaling from multiple local sites involved in this referred pain network.

State of the art in EEG signal features of mindfulness-based treatments for chronic pain

A systematic review of electroencephalographic (EEG) correlates of Mindfulness- based treatment for chronic pain is presented. Recent technological advances have made EEG acquisition more accessible and also reliable. EEG monitoring before, during, and after treatment might support efficacy assessment and enable real- time adaptive intervention. The preliminary research extracted 131 papers from 6 scientific search engines. The application of the exclusion criteria led to the selection of 4 papers, indicating that the topic is still unexplored and further investigations are required. The collected papers exhibited great variability making challenging the comparison, nevertheless promising EEG correlates emerged. In particular, pain-related evoked potentials correlate with Mindfulness-Based treatment. EEG source analysis revealed the prevalent involvement of regions modulating emotional responses. In addition, higher baseline theta power was associated with greater improvement in depression when Mindfulness-based treatments are administered. This last result makes EEG also suitable for evaluating which patients can benefit most from mindfulness-based treatments.

Development, Implementation, and Evaluation of a 'Virtual Patient' with Chronic Low Back Pain: An Education Resource for Physiotherapy Students

Background: The management of chronic pain is inherently multidisciplinary, requiring collaboration across health and care professions because pain is multidimensional, involving psychological, social, biomedical, cultural, and environmental factors. However, pain education has often focused more on biomedical aspects, limiting the capacity of professionals to deliver integrated, person-centred care. Shifting pain education away from biomedically driven curricula may better prepare graduates for meaningful consultations and biopsychosocial care. Objective: This manuscript reports the development and pilot evaluation of a virtual patient simulation designed to help physiotherapy students develop person-centred pain assessment skills. Methods: We developed and piloted a virtual patient with complex pain scenarios for physiotherapy students. To evaluate the simulation, students completed a self-reported questionnaire assessing their ability, self-confidence in person-centred assessment skills, and their attitudes and beliefs regarding the simulation. Results: Frequency and confidence in person-centred inquiry ranged from 100% to 16.3%, depending on the complexity of information. Inductive thematic analysis revealed four themes: (1) Environmental factors & preferences-students' preference for the learning environment; (2) Learning experience-including engagement, feedback, discussions, and a 'safe' space for building confidence; (3) Professional development-insights into person-centred inquiry, personal biases, and emotional challenges; (4) Limitations-including the desire for more complexity, and technical challenges noted. Conclusions: The development of this virtual patient simulation enabled healthcare students to engage with a multidimensional perspective on pain, fostering skills essential for biopsychosocial pain assessment and patient-centred care. Although designed and piloted with physiotherapy students, this model holds potential for broader application across healthcare disciplines.

Association of visceral adiposity index and chronic pain in US adults: a cross-sectional study

The Visceral Obesity Index (VAI) is utilized as a metric employed to assess the distribution of abdominal adipose tissue as well as the functional status of adipose tissue. Nevertheless, the interplay between VAI and persistent pain has yet to be investigated. This cross-sectional analysis investigated the relationship between VAI and persistent pain among 1357 American adults from NHANES data. A logarithmic transformation of VAI was performed to adjust for skewness. Following the adjustment for relevant variables, logistic regression analysis showed a noteworthy association between VAI and chronic pain, suggesting that higher VAI values may be linked to an increased prevalence of persistent pain. Curve fitting analysis revealed a nonlinear correlation, with a breakpoint at a VAI value of 0.18. For VAI values below this threshold, each unit increase was notably correlated with an elevated prevalence of persistent pain, while increases in VAI beyond this threshold did not show a significant impact on chronic pain prevalence. Subgroup analyses indicated that the VAI may serve as a relatively independent risk factor for persistent pain. These findings highlight the possibility of incorporating abdominal adipose modification into pain management approaches and emphasize the critical importance of monitoring visceral fat accumulation to better identify patients more susceptible to chronic pain.

The feasibility and acceptability of an online mindfulness-based stress reduction program for chronic musculoskeletal pain: protocol for a pilot randomised controlled trial

BACKGROUND

Chronic musculoskeletal pain conditions affect millions of people worldwide and place a significant burden on individuals and the healthcare systems. Managing chronic musculoskeletal pain requires a multidisciplinary approach that considers biological, psychological, and social factors. However, access to multidisciplinary pain care is challenging, and long wait times can lead to increased stress and health deterioration. Mindfulness-based stress reduction (MBSR) is a mind-body approach developed specifically to reduce the distress of living with chronic conditions, such as chronic musculoskeletal pain. This study proposed a novel approach by offering an online MBSR program to patients on waitlists to attend a multidisciplinary pain clinic in Australia's public healthcare system that could improve health outcomes. The study aims to assess the feasibility, acceptability, and potential efficacy of this approach using a pilot study design with a mixed-methods approach.

METHODS

This is a mixed-methods pilot randomised controlled trial with an embedded qualitative study. Participants will be recruited from waitlists at two multidisciplinary pain management centres within the Sydney Local Health District in New South Wales, Australia. This pilot trial will randomly assign 32 individuals with chronic musculoskeletal pain to either an online MBSR group or a usual care control group. Feasibility outcomes, patient-reported outcomes, adherence to mindfulness practice, and adverse events will be assessed using validated questionnaires. Semi-structured interviews will be conducted with participants in the MBSR group to explore their experiences and evaluate acceptability, and barriers and facilitators of engagement with the intervention.

DISCUSSION

This pilot study will evaluate a novel approach to integrating MBSR into the Australian public healthcare system as a mechanism for providing support to individuals with chronic musculoskeletal pain who are waitlisted for a multidisciplinary pain management program. Findings from this study will indicate the feasibility, acceptability, safety, and preliminary efficacy of this approach in terms of patient-reported outcomes to guide the design of future large-scale clinical trials.

TRIAL REGISTRATION

This trial was prospectively registered in the Australian New Zealand Clinical Trials Registry (ACTRN12622000822785).

Chronic postsurgical pain in the ICD-11: implications for anaesthesiology and pain medicine

Chronic postsurgical pain (CPSP) is associated with reduced health-related quality of life and disability. In some patients, it can result in long-term opioid use even after minor surgery. Epidemiological studies have reported highly varying rates of CPSP, largely because researchers have used different definitions with self-defined cut-offs for pain scores. With the introduction of the 11th revision of the World Health Organisation International Classification of Diseases and Related Health Problems (ICD-11), chronic pain is now recognised as an entity of its own, its biopsychosocial nature is emphasised, and its definition is standardised. Compared with the ICD-11 definition, the prevalence of CPSP might have been overestimated in previous studies. The ICD-11 provides a multifactorial assessment of pain severity, referring to pain intensity, pain-related interference, and pain-related distress, which cover the biopsychosocial aspects of chronic pain. These three scores can be added as extension codes to any pain diagnosis. Harmonisation of the CPSP criteria within the different coding levels of the ICD-11 might improve discrimination of CPSP from other chronic pain conditions not induced by surgery. Although neuropathic CPSP increases pain severity and requires alternative therapeutic approaches to nociceptive pain, a specific code to differentiate between neuropathic and non-neuropathic CPSP is not available. For clinical practice and research, the evidence-based ICD-11 definition, which provides clear-cut diagnostic criteria, should generally be used instead of pain scores alone. This will improve the comparability of data, form the basis for future diagnostic and therapeutic approaches, and facilitate communication.

Non-neurodestructive ganglion impar blocks for coccydynia and related disorders: a systematic review and meta-analysis

BACKGROUND/IMPORTANCE

Chronic coccydynia is a challenging condition to manage. Conflicting evidence exists regarding the role of the ganglion impar in coccygeal nociception. When conservative treatments fail, minimally invasive interventions at the ganglion impar may be effective in providing relief.

OBJECTIVES

To evaluate the effectiveness and safety of ganglion impar blocks (GIBs) for the management of chronic coccydynia.

EVIDENCE REVIEW

A systematic review and meta-analysis was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies were identified through a comprehensive literature search of PubMed, Embase Classic+ Embase, CINAHL and the Web of Science in February 2024. Data on patient characteristics, intervention details, pain outcomes (measured by Visual Analog Scale and Numerical Pain Rating Scale) and adverse events were extracted. Meta-analysis was performed using standardized mean differences (SMDs) on scale of 0 to 10.

FINDINGS

Seventeen studies described 625 coccydynia patients treated with GIB. All studies reported some level of improvement of pain after GIB. The meta-analysis included 11 studies totaling 391 patients with a baseline pain score of 7.93 (7.81 to 8.04 95% CI). GIBs were effective in reducing coccygeal pain at short-term (up to 3 months), intermediate-term (3-6 months) and long-term (greater than 6 months) follow-up. SMDs were -2.73 (95% CI -3.45 to -2.01), -3.22 (95% CI -2.82 to -1.45), -1.86 (95% CI -2.58 to -1.15) at 3 months, 3-6 months and >6 months, respectively. No serious adverse events were noted. Grading of Recommendations Assessment, Development and Evaluation assessment indicated 'very low' certainty of evidence across all outcomes.

CONCLUSIONS

Non-neurodestructive GIB may be a safe and potentially effective treatment option for patients with chronic, refractory coccydynia.

PROSPERO REGISTRATION NUMBER

CRD42024506056.

Evaluating amitriptyline's role in chronic TMD management: a placebo-controlled trial

BACKGROUND

To assess the effectiveness of low-dose amitriptyline in reducing pain and improving oral health-related quality of life in individuals with chronic temporomandibular disorders (TMD) over a 2-month period, compared to placebo.

METHODS

Forty participants were randomly assigned to receive either 25 mg of amitriptyline or a placebo pill for 2 months. The primary outcome was pain intensity, measured using a visual analogue scale (VAS). The secondary outcome was the impact of pain on oral health-related quality of life, assessed by the Oral Health Impact Profile questionnaire (OHIP-14). Evaluations were conducted at baseline and after the 1st and 2nd months of treatment.

RESULTS

No statistically significant differences were observed between the treatment groups at baseline (p > 0.05). After 2 months of treatment participants in amitriptyline group experienced a significantly greater reduction in spontaneous pain, with a 63.3% decrease in VAS scores. Participants in placebo group showed a much smaller reduction in spontaneous pain, with only a 16.2% decrease in VAS scores. Additionally, the amitriptyline group demonstrated a significant improvement in OHIP-14 scores (p < 0.001), whereas the placebo group showed no significant change in oral health-related quality of life (p = 0.184).

CONCLUSION

This study highlights low-dose amitriptyline as an effective treatment for chronic TMD, showing significant pain reduction and improved quality of life, underscoring its value in a multimodal approach despite the need for further research to personalize care.

TRIAL REGISTRATION

This study was registered retrospectively in ISRCTNregistry under the number ISRCTN17622685, on 01/10/2024.

Prevalence of Depression and Anxiety Among Adults With Chronic Pain: A Systematic Review and Meta-Analysis

Importance

Depression and anxiety are common among adults with chronic pain, but their prevalence is unclear.

Objectives

To evaluate the prevalence of depression and anxiety among adults with chronic pain and identify factors that moderate prevalence.

Data Sources

A literature search was conducted of MEDLINE, Embase, PsycINFO, and Cochrane Library from January 2013 to October 2023.

Study Selection

Studies reporting the prevalence of depression or anxiety using a validated assessment tool among adults with chronic pain (excluding chronic headache disorders).

Data Extraction and Synthesis

A total of 31 159 initial records were identified, and 5177 full texts were screened. Data were extracted per the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline using Covidence. Two independent reviewers completed abstract screening, full-text review, and data extraction and rated risk of bias. Random-effects meta-analyses were applied to pool prevalence, assess moderation, and compare prevalence of depression or anxiety among samples with chronic pain vs control samples.

Main Outcomes and Measures

Prevalence of depression and anxiety based on clinically significant symptoms or diagnosis. The moderators of prevalence identified were pain condition, recruitment setting, continent, age, percentage female, and pain duration.

Results

The search identified 376 studies from 50 countries comprising 347 468 individuals (mean [SD] age, 51.3 [9.5] years; 70.0% female) with chronic pain. Among adults with chronic pain, clinical symptoms of depression were present in 39.3% (95% CI, 37.3%-41.1%; I2 = 98.9%), and clinical symptoms of anxiety were present in 40.2% (95% CI, 38.0%-42.4%; I2 = 99.0%). Prevalence differed by pain condition (highest among samples of people with fibromyalgia [depression, 54.0% (95% CI, 48.5%-59.4%); anxiety, 55.5% (95% CI, 50.4%-60.4%)]; lowest among samples of people with arthritis conditions [eg, osteoarthritis: depression, 29.1% (95% CI, 20.3%-39.7%); anxiety, 17.5% (95% CI, 6.6%-38.8%)]) and was highest among younger people (depression, β = -0.02 [95% CI, -0.03 to -0.01]; anxiety, β = -0.02 [95% CI, -0.03 to -0.01]) and women (depression, β = 0.69 [95% CI, 0.31-1.08]; anxiety, β = 0.90 [95% CI, 0.48-1.33]). With regard to diagnoses, 36.7% (95% CI, 29.0%-45.1%) had a major depressive disorder, and 16.7% (95% CI, 11.8%-23.2%) had generalized anxiety disorder. Women, younger people, and people with nociplastic pain (ie, pain arising from altered nociception without tissue damage) were most likely to have depression and anxiety.

Conclusions and Relevance

In this systematic review and meta-analysis of depression and anxiety among individuals with chronic pain, approximately 40% of adults had clinically significant depression and anxiety. Women, younger people, and people with nociplastic pain were most likely to have depression and anxiety. The co-occurrence of chronic pain with depression and anxiety is a significant public health concern necessitating routine screening in clinical settings, equitable access to specialty care, and innovative treatment development.

How does chronic psychosocial distress induce pain? Focus on neuroinflammation and neuroplasticity changes

Chronic primary pain including fibromyalgia for the musculoskeletal system persists for more than 3 months. Its etiological factors and the pathophysiological mechanisms are not known, and therefore, there is no satisfactory therapy, it is an unmet medical need condition. The only etiological and aggravating factor is chronic psychosocial distress, which is known to cause neuroimmune and endocrine changes both in the periphery and the central nervous system. In this short review, we introduce our research perspective by summarizing the recent literature on the interactions between chronic pain, stress, and commonly co-morbid mood disorders. Immune activation, autoimmunity, neuro-immune-vascular crosstalks and neuroinflammation play roles in the pathophysiology of these conditions. Data on stress-induced neuroplasticity changes at cellular and molecular levels were also collected in relation to chronic primary pain both from clinical studies and animal experiments of translational relevance. Understanding these mechanisms could help to identify novel therapeutic targets for chronic primary pain including fibromyalgia.

Refining chronic pain phenotypes: A comparative analysis of sociodemographic and disease-related determinants using electronic health records

The use of electronic health records (EHR) for chronic pain phenotyping has gained significant attention in recent years, with various algorithms being developed to enhance accuracy. Structured data fields (e.g., pain intensity, treatment modalities, diagnosis codes, and interventions) offer standardized templates for capturing specific chronic pain phenotypes. This study aims to determine which chronic pain case definitions derived from structured data elements achieve the best accuracy, and how these validation metrics vary by sociodemographic and disease-related factors. We used EHR data from 802 randomly selected adults with autoimmune rheumatic diseases seen at a large academic center in 2019. We extracted structured data elements to derive multiple phenotyping algorithms. We confirmed chronic pain case definitions via manual chart review of clinical notes, and assessed the performance of derived algorithms, e.g., sensitivity/recall, specificity, positive predictive value (PPV). The highest sensitivity (67%) was observed when using ICD codes alone, while specificity peaked at 96% with a quadrimodal algorithm combining pain scores, ICD codes, prescriptions, and interventions. Specificity was generally higher in males and younger patients, particularly those aged 18-40 years, and highest among Asian/Pacific Islander and privately insured patients. PPV was highest among patients who were female, younger, or privately insured. PPV and sensitivity were lowest among males, Asian/Pacific Islander, and older patients. Variability of phenotyping results underscores the importance of refining chronic pain phenotyping algorithms within EHRs to enhance their accuracy and applicability. While our current algorithms provide valuable insights, enhancement is needed to ensure more reliable chronic pain identification across diverse patient populations. PERSPECTIVE: This study evaluates chronic pain phenotyping algorithms using electronic health records, highlighting variability in performance across sociodemographic and disease-related factors.

The medico-legal pertinence of musculoskeletal nociplastic pain

Pain conditions can be challenging; nociplastic pain, defined as pain that cannot be sufficiently explained by structural/anatomical changes, is newly categorised as the third pain mechanism. Nociplastic pain complaints are subjective, often accompanied by symptoms of fatigue, sleep and mood disturbance and cognitive difficulties with no diagnostic biomarker or reliable measurement of severity. Medico-legal challenges include attribution of causation after an alleged triggering event, assessment of severity, and reported functional impairment. This review considers nociplastic pain in regard to the musculoskeletal system with focus on causation and temporality of the pain condition and impairment. We hope that this overview will provide a better understanding of these challenging pain conditions.

Chronic pain: a modifiable target to reduce perioperative cardiovascular morbidity

Recent epidemiological studies suggest that chronic pain is a clinically under-recognised cause for cardiovascular morbidity and mortality. Up to 30% of patients undergoing surgery report chronic pain, but the impact of pre-existing pain on postoperative cardiovascular outcomes is not known. Chronic pain and cardiovascular dysfunction share fundamental pathological mechanisms. Chronic pain is a modifiable risk factor for perioperative cardiovascular morbidity.

Fourteen-Year Retrospective Cohort Study on the Impact of Climatic Factors on Chronic Musculoskeletal Pain: A Spanish Primary Care Analysis

INTRODUCTION

Chronic musculoskeletal pain, often affected by environmental factors such as temperature, humidity, and atmospheric pressure, can influence pain perception and increase the number of healthcare visits.

OBJECTIVE

This study examined the link between climate variables and referral rates for chronic musculoskeletal pain in Spanish primary care over 14 years and evaluated the impact of climatic factors on rehabilitation referrals based on variations in pain type, age, and sex.

METHODS

A retrospective cohort of 44 212 adults diagnosed with chronic musculoskeletal pain (2010-2023) across three primary care centers was analyzed. The inclusion criteria were CIAP2 (International Classification of Primary Care, second edition) diagnostic codes, with ethical clearance from the Puerta de Hierro Majadahonda Hospital (PI 70/24). This study adhered to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines for observational reporting. Climatic data, including temperature, precipitation, wind speed, hours of sunlight, and barometric pressure, were obtained from (Agencia Estatal de Meteorología). Statistical analyses used ARIMAX (AutoRegressive Integrated Moving Average with eXternal regressors) and ETSX (Exponential Smoothing State Space Model with eXternal regressors) models, optimizing model fit through root mean squared error (RMSE), mean absolute percentage error (MAPE), and mean absolute scaled error (MASE).

RESULTS

Significant associations were found between climate factors and referral rates. Higher minimum temperatures reduced shoulder/arm pain referrals by -0.019 (95% CI: -0.036, -0.002; p < 0.05). Male patients were more likely to consult, with age being inversely linked to thoracic/lumbar pain (-0.044; 95% CI: -0.071, -0.018; p < 0.05) and positively associated with shoulder/arm pain (0.038; 95% CI: 0.024, 0.052; p < 0.05). ARIMAX was optimal for most pain types, except for cervical pain, for which ETSX was better.

CONCLUSIONS

Climatic factors, such as temperature and pressure, affect referral patterns, highlighting the need for climate-sensitive healthcare planning to aid resource management and patient guidance on pain in varying weather conditions.