Prevalence of functional disorders across Europe: a systematic review and meta-analysis

Functional Disorders (FD) refer to persistent somatic symptoms caused by changes in the functioning of bodily processes. Previous findings suggest that FD are highly prevalent, but overall prevalence rates for FD in European countries are scarce. Therefore, the aim of the present work was to estimate the point prevalence of FD in adult general populations. PubMed and Web of Science were searched from inception to June 2022. A generalized linear mixed-effects model for statistical aggregation was used for statistical analyses. A standardized quality assessment was performed, and PRISMA guidelines were followed. A total of 136 studies were included and systematically synthesized resulting in 8 FD diagnoses. The large majority of studies was conducted in the Northern Europe, Spain, and Italy. The overall point prevalence for FD was 8.78% (95% CI from 7.61 to 10.10%) across Europe, with the highest overall point prevalence in Norway (17.68%, 95% CI from 9.56 to 30.38%) and the lowest in Denmark (3.68%, 95% CI from 2.08 to 6.43%). Overall point prevalence rates for specific FD diagnoses resulted in 20.27% (95% CI from 16.51 to 24.63%) for chronic pain, 9.08% (95% CI from 7.31 to 11.22%) for irritable bowel syndrome, and 8.45% (95% CI from 5.40 to 12.97%) for chronic widespread pain. FD are highly prevalent across Europe, which is in line with data worldwide. Rates implicate the need to set priorities to ensure adequate diagnosis and care paths to FD patients by care givers and policy makers.

Pain Catastrophizing as a Mediator Between Pain Self-Efficacy and Disease Severity in Patients with Fibromyalgia

BACKGROUND

Fibromyalgia (FM) is characterized by chronic widespread pain, fatigue, sleep disturbances, cognitive impairment, and mood disturbance. Both pain catastrophizing and pain self-efficacy have been found to be mediators of pain treatment effectiveness. However, whether pain catastrophizing mediates the association between pain self-efficacy and FM severity remains unclear.

AIM

To examine whether pain catastrophizing mediates the association between pain self-efficacy and disease severity in patients with FM.

METHODS

This cross-sectional study included the baseline data of 105 people with FM from a randomized controlled trial. Hierarchical linear regression analysis was performed to examine the predictive ability of pain catastrophizing for FM severity. Furthermore, we examined the mediating effect of pain catastrophizing on the association between pain self-efficacy and FM severity.

RESULTS

Pain self-efficacy was negatively associated with pain catastrophizing (β = -.4043, p < .001). FM severity was positively associated with pain catastrophizing (β = .8290, p < .001) and negatively associated with pain self-efficacy (β = -.3486, p = .014). Pain self-efficacy had a direct effect on FM severity (β = -.6837, p < .001) and an indirect effect on FM severity through the effect of pain catastrophizing (β = -.3352, 95% CI bootstrapping -.5008 to -.1858).

CONCLUSION

Pain catastrophizing independently predicts FM severity and mediates the association between pain self-efficacy and FM severity. Pain catastrophizing should be monitored through interventions aimed at improving pain self-efficacy to reduce symptom burden in patients with FM.

Racial Disparities in Pain Among Women with Fibromyalgia: Secondary Data Analysis of Severity, Interference with Function, and Response to Guided Imagery

Background: Fibromyalgia syndrome (FMS) is characterized by widespread persistent musculoskeletal pain. Mostly prevalent among White women, little is known about FMS in other population cohorts. This study examined secondary data of a racially diverse sample of women with FMS that were collected as part of a randomized controlled clinical trial that examined the effect of a complementary therapy intervention over the course of a 10-week guided imagery intervention to identify demographic, social, or economic differences in self-reported pain. Materials and Methods: The Brief Pain Inventory (BPI), which measures pain severity and interference, was administered to 72 women (21 Black and 51 Whites) at baseline, 6 and 10 weeks. Student's t tests and time series regression models examined racial difference in pain dimensions and treatment response. Regression models accounted for age, race, income, duration of symptoms, treatment group, pain at baseline, smoking, alcohol use, comorbid conditions, and time. Results: Black women experienced significantly higher pain severity (β = 5.52, standard deviation [SD] = 2.13) and interference (β = 5.54, SD = 2.74) than Whites (severity β = 4.56, SD = 2.08; interference β = 4.72, SD = 2.76) (interference: t = 1.92, p = 0.05; severity: t = 2.95, p = 0.00). Disparities persisted over time. Controlling for differences in age, income, and previous pain levels, Black women had 0.26 (standard error [SE] = 0.065) higher pain severity and 0.36 (SE = 0.078) higher interference than Whites. Low-income earners also experienced 2.02 (SE = 0.38) and 2.19 (SE = 0.46) higher pain severity and interference, respectively, than other earners. Results were robust to inclusion of comorbidities. Conclusions: Black women and low-income earners experienced significantly higher levels of pain severity and interference and a lower dose response to the intervention. Differentials were robust to inclusion of demographic, health, and behavioral characteristics. Findings suggest that external factors may contribute to pain perception among women with FMS.

The prevalence of chronic pain in young adults: a systematic review and meta-analysis

ABSTRACT

Prior systematic reviews have summarized the prevalence and impact of chronic pain in "average" pediatric (i.e., school-age) and adult (i.e., middle-age) age groups. To our knowledge, this is the first study to describe the prevalence of chronic pain in the subgroup of individuals that fall in between established boundaries of "childhood" and "adulthood" - known as young adulthood. The goal of this research was to meta-analyze prevalence data on pain in young adults based on available data published between 2008 and 2020. Searches were identified with MEDLINE, Embase, and PsycINFO. We included general population and university-based studies presenting prevalence estimates of chronic pain (pain lasting ≥3 months) in young adults. We identified 43 articles providing prevalence estimates across a combined population of 97,437 young adult respondents (age range: 15-34), with studies undertaken in 22 countries. Available data allowed for stratification of prevalence according to pain condition. The overall pooled random-effect prevalence rate of chronic pain in young adults was 11.6%, suggesting that 1 in every 9 young adults experience chronic pain worldwide. Prevalence rates varied considerably according to pain condition. Estimates did not vary according to sex, geographic location, and several study methodological characteristics (i.e., population type, sampling area, sampling year, investigation period, assessment method). Overall, young adult chronic pain is common and should be recognized as a major public health concern. Considering the difficulties young adults face accessing adult healthcare, greater attention is needed to develop transition programs and evidence-based treatments tailored to the unique needs of this age group.

Challenges of translating epidemiologic research: An application to rheumatic and musculoskeletal disorders

Translation of research into public health policy is featured in common definitions of epidemiology, as an end result of scientific discovery on disease occurrence and causes. This dual nature of epidemiology, which brings together discovery and its use, seems to imply two main dimensions by which to judge epidemiologic research: technical or field-specific quality and societal value. This paper uses our research on the epidemiology of rheumatic and musculoskeletal disorders as a starting point to discuss the interface between these dimensions, exploring a number of conceptual, practical and ethical challenges that epidemiologists increasingly need to address when aiming for research translation. Those include not only the appraisal of the technical quality of research, which is familiar to researchers, but also the judgement on the usefulness and actual use of knowledge, as well as the assessment of the legitimacy of research based on translation potential. Several challenges lie ahead, but interdisciplinary conceptual and technical developments have the potential to guide future epidemiologic research of consequence. Approaches that recognize complexity and formalize the involvement of stakeholders in the research process within transparent frameworks open promising avenues for an effective translation of epidemiologic research projected into the future.

3D magnetic resonance spectroscopic imaging reveals links between brain metabolites and multidimensional pain features in fibromyalgia

BACKGROUND

Fibromyalgia is a centralized multidimensional chronic pain syndrome, but its pathophysiology is not fully understood.

METHODS

We applied 3D magnetic resonance spectroscopic imaging (MRSI), covering multiple cortical and subcortical brain regions, to investigate the association between neuro-metabolite (e.g. combined glutamate and glutamine, Glx; myo-inositol, mIno; and combined (total) N-acetylaspartate and N-acetylaspartylglutamate, tNAA) levels and multidimensional clinical/behavioural variables (e.g. pain catastrophizing, clinical pain severity and evoked pain sensitivity) in women with fibromyalgia (N = 87).

RESULTS

Pain catastrophizing scores were positively correlated with Glx and tNAA levels in insular cortex, and negatively correlated with mIno levels in posterior cingulate cortex (PCC). Clinical pain severity was positively correlated with Glx levels in insula and PCC, and with tNAA levels in anterior midcingulate cortex (aMCC), but negatively correlated with mIno levels in aMCC and thalamus. Evoked pain sensitivity was negatively correlated with levels of tNAA in insular cortex, MCC, PCC and thalamus.

CONCLUSIONS

These findings support single voxel placement targeting nociceptive processing areas in prior ¹ H-MRS studies, but also highlight other areas not as commonly targeted, such as PCC, as important for chronic pain pathophysiology. Identifying target brain regions linked to multidimensional symptoms of fibromyalgia (e.g. negative cognitive/affective response to pain, clinical pain, evoked pain sensitivity) may aid the development of neuromodulatory and individualized therapies. Furthermore, efficient multi-region sampling with 3D MRSI could reduce the burden of lengthy scan time for clinical research applications of molecular brain-based mechanisms supporting multidimensional aspects of fibromyalgia.

SIGNIFICANCE

This large N study linked brain metabolites and pain features in fibromyalgia patients, with a better spatial resolution and brain coverage, to understand a molecular mechanism underlying pain catastrophizing and other aspects of pain transmission. Metabolite levels in self-referential cognitive processing area as well as pain-processing regions were associated with pain outcomes. These results could help the understanding of its pathophysiology and treatment strategies for clinicians.

Can psychological factors be associated with the severity of pain and disability in patients with fibromyalgia? A cross-sectional study

Introduction: Psychological processes can play an important role in the expression and clinical impact of fibromyalgia.Objective: To investigate the association between the severity of pain and disability and psychological factors in patients with fibromyalgia.Methods: The following outcomes were assessed in 104 patients with fibromyalgia: pain intensity, using the Pain Numerical Rating Scale; disability, using the Patient-Specific Functional Scale; depression, using the Beck Depression Scale; anxiety, using the State-Trait Anxiety Inventory; kinesiophobia, using the Tampa Scale for Kinesiophobia; pain catastrophizing, using the Pain Catastrophizing Scale; beliefs and attitudes toward pain, using the Survey of Pain Attitudes; and the occurrence of abuse during some stage of life. Statistical analysis was performed using SPSS version 15. Initially, a simple regression analysis was performed between the dependent variables (pain and disability) and the other variables with a significance level of p ≤ 0.20, and then a multiple regression analysis was performed with a significance level of p ≤ 0.05.Results: Depression was found to be associated with pain severity (β = 0.07 [95% CI: 0.02 to 0.11], p = .00), and kinesiophobia was found to be associated with disability severity (β = -0.06 [95% CI: -0.09 to -0.02], p = .00). Depression can explain 10% of the variability of pain intensity, while kinesiophobia can explain 9% of the variability of disability.Conclusion: There are weak associations that are not clinically relevant between depression and pain severity, and between kinesiophobia and disability severity. However, other psychological factors are not associated with the severity of pain or disability.

Stability of serum ferritin measured by immunoturbidimetric assay after storage at -80°C for several years

Background

Iron deficiency (ID) may impair long-term neurological development when it occurs in young infants. In cohort studies, it is sometimes necessary to evaluate ID with sera kept frozen for several years. To assess ID, learned societies recommend measuring serum ferritin (SF) level combined with C-reactive protein level. The long-term stability of C-reactive protein in frozen samples is well established but not ferritin.

Methods

We measured SF level (immunoturbidimetric assay; in micrograms per liter) immediately after collection from 53 young adults recruited and followed-up in Porto, Portugal, from 2011 to 2013 (SF₁), and then, in 2016 in two aliquots kept frozen at– 80°C for 3 to 5 years: one without (SF_2A) and one with (SF_2B) intermediate thawing in 2014. We compared SF₁ to SF_2A then SF_2B; statistical agreement was evaluated by the Bland and Altman method and the effect of intermediate thawing by regression modelling.

Results

Mean SF_2A–SF₁ and SF_2B–SF₁ differences were -2.1 (SD 7.0) and 48.9 (SD 66.9). Values for Bland and Altman 95% limits of agreement were higher for the comparison of SF_2B and SF₁ than SF_2A and SF₁: -82.2 to 179.9 and -15.8 to 11.8, respectively; the effect of thawing was highly significant (p <0.001).

Conclusions

Agreement between SF values before and after 3 to 5 years of constant freezing at -80°C was in a generally accepted range, which supports the hypothesis of ferritin’s stability at this temperature for a long period. In long-term storage by freezing, intermediate thawing induced a major increase in values.

Clinical, psychological features and quality of life of fibromyalgia patients: a cross-sectional study of Chinese sample

This study aimed to determine the clinical, psychological features, and quality of life in Chinese fibromyalgia (FM) patients who fulfilled the American College of Rheumatology (ACR) 2010 FM classification criteria at initial diagnosis. A cross-sectional study was carried out in the Chinese People's Liberation Army (PLA) General Hospital. A hundred and seven Chinese FM patients (86 females, 21 males) were included. Eighty-six patients completed the questionnaires. Descriptive, differences, and correlation analyses were performed. The results showed that Chinese FM patients started their diseases at a median age of 37 years, with a male-to-female ratio of 1:4.1. Most patients were diagnosed about 2 years after symptoms onset. Nearly 60 % (59.81%) patients had less than college education, 58.88% did not have a full-time job, and 41.12% had low-back pain. Out of 86 patients, 58 (67.4%) had anxiety and 75 (87.2%) had depression. FM patients had poor quality of life in each aspect and deficient social support. The level of pain for the past 7 days was strongly correlated with patient global impression of severity (PGI-S; r = 0.651, p < 0.001) and patient global impression of bother (PGI-B; r = 0.628, p < 0.001). PGI-B was correlated with seven subscales of short-form health survey (SF-36). The study demonstrated the clinical, psychological features of Chinese patients. The diagnosis was delayed for about 2 years. Most of the patients had anxiety and depression, had poor quality of life, and lacked proper social support. PGI-B might be a simple measurement to evaluate patients' quality of life.

Factors associated with high pain intensity during wound care procedures: A model

The most common wound care procedures (WPCs) performed on open wounds are dressing changes and wound cleansing. Dressing changes cause moderate to severe pain in 74% of patients, nearly half (36%) of whom experience severe pain (rated as 8-10 on a 10-point numeric rating scale). The purpose of this paper is to propose a model of clinically accessible factors that can be tested in order to develop a clinical tool to identify which patients are likely to experience high intensity pain during nonoperative WCPs, such as dressing changes. Although multiple factors are known to be associated with pain, the factors selected for this model were limited to those that (1) are supported based on evidence and/or pain mechanisms and (2) are readily accessible to clinicians/practitioners and can be tested as a prediction tool to be used prior to WCPs. This model may be helpful to identify those likely to experience high intensity pain during WCPs. In this way, use of aggressive pain management strategies, including specialty dressings, pharmacologic analgesics, and/or non-pharmacological strategies, such as high intensity transcutaneous electrical stimulation.

2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria

OBJECTIVES

The provisional criteria of the American College of Rheumatology (ACR) 2010 and the 2011 self-report modification for survey and clinical research are widely used for fibromyalgia diagnosis. To determine the validity, usefulness, potential problems, and modifications required for the criteria, we assessed multiple research reports published in 2010-2016 in order to provide a 2016 update to the criteria.

METHODS

We reviewed 14 validation studies that compared 2010/2011 criteria with ACR 1990 classification and clinical criteria, as well as epidemiology, clinical, and databank studies that addressed important criteria-level variables. Based on definitional differences between 1990 and 2010/2011 criteria, we interpreted 85% sensitivity and 90% specificity as excellent agreement.

RESULTS

Against 1990 and clinical criteria, the median sensitivity and specificity of the 2010/2011 criteria were 86% and 90%, respectively. The 2010/2011 criteria led to misclassification when applied to regional pain syndromes, but when a modified widespread pain criterion (the "generalized pain criterion") was added misclassification was eliminated. Based on the above data and clinic usage data, we developed a (2016) revision to the 2010/2011 fibromyalgia criteria. Fibromyalgia may now be diagnosed in adults when all of the following criteria are met: CONCLUSIONS: The fibromyalgia criteria have good sensitivity and specificity. This revision combines physician and questionnaire criteria, minimizes misclassification of regional pain disorders, and eliminates the previously confusing recommendation regarding diagnostic exclusions. The physician-based criteria are valid for individual patient diagnosis. The self-report version of the criteria is not valid for clinical diagnosis in individual patients but is valid for research studies. These changes allow the criteria to function as diagnostic criteria, while still being useful for classification.

A Decade of Gabapentinoid Misuse: An Analysis of the European Medicines Agency's 'Suspected Adverse Drug Reactions' Database

INTRODUCTION

The gabapentinoids pregabalin and gabapentin are being increasingly prescribed for a range of clinical conditions. Recently, although gabapentinoids at therapeutic dosages may present with low addictive liability levels, cases of misuse and rising numbers of related fatalities have been reported.

OBJECTIVES

The aim of the study was to identify and assess cases of gabapentinoid misuse or dependence as reported to the European Medicines Agency's EudraVigilance database, to identify the magnitude of this problem and the characteristics of these reactions.

METHODS

All spontaneous reports of both gabapentin- (2004-2015) and pregabalin- (2006-2015) related misuse/abuse/dependence were retrieved. A descriptive analysis by source, sex, age, and type of report was performed.

RESULTS

From the EudraVigilance database 7639 (6.6 % of a total of 115,616) and 4301 (4.8 % of 90,166) adverse drug reaction reports of misuse/abuse/dependence were, respectively, associated with pregabalin and gabapentin, with an overall reporting frequency increasing over time. For both molecules, subjects typically involved were female adults. A total of 27 and 86 fatalities, respectively, associated with pregabalin and gabapentin, and mostly in combination with opioids, were identified. Analysis of proportional reporting ratios for drug abuse/dependence/intentional product misuse values seem to indicate that these adverse drug reactions were more frequently reported for pregabalin (1.25, 1.39, and 1.58, respectively) compared with gabapentin.

CONCLUSIONS

Despite data collection/methodological approach limitations, the present data seem to suggest that gabapentinoid misuse may be a cause for concern, especially in patients with a history of substance misuse. Hence, healthcare professionals should be vigilant when prescribing these molecules.

Fibromyalgia syndrome pathology and environmental influences on afflictions with medically unexplained symptoms

Fibromyalgia syndrome (FMS) is a clinical disorder predominant in females with unknown etiology and medically unexplained symptoms (MUS), similar to other afflictions, including irritable bowel syndrome (IBS), chronic fatigue syndrome (CFS), post-traumatic stress disorder (PTSD), Gulf War illness (GFI), and others. External environmental stimuli drive behavior and impact physiologic homeostasis (internal environment) via autonomic functioning. These environments directly impact the individual affective state (mind), which feeds back to regulate physiology (body). FMS has emerged as a complex disorder with pathologies identified among neurotransmitter and enzyme levels, immune/cytokine functionality, cortical volumes, cutaneous innervation, as well as an increased frequency among people with a history of traumatic and/or emotionally negative events, and specific personality trait profiles. Yet, quantitative physical evidence of pathology or disease etiology among FMS has been limited (as with other afflictions with MUS). Previously, our group published findings of increased peptidergic sensory innervation associated with the arterio-venous shunts (AVS) in the glabrous hand skin of FMS patients, which provides a plausible mechanism for the wide-spread FMS symptomology. This review focuses on FMS as a model affliction with MUS to discuss the implications of the recently discovered peripheral innervation alterations, explore the role of peripheral innervation to central sensitization syndromes (CSS), and examine possible estrogen-related mechanisms through which external and internal environmental factors may contribute to FMS etiology and possibly other afflictions with MUS.

Towards Tailored Patient's Management Approach: Integrating the Modified 2010 ACR Criteria for Fibromyalgia in Multidimensional Patient Reported Outcome Measures Questionnaire

Objectives. To assess the validity, reliability, and responsiveness to change of a patient self-reported questionnaire combining the Widespread Pain Index and the Symptom Severity Score as well as construct outcome measures and comorbidities assessment in fibromyalgia patients. Methods. The PROMs-FM was conceptualized based on frameworks used by the WHO Quality of Life tool and the PROMIS. Initially, cognitive interviews were conducted to identify item pool of questions. Item selection and reduction were achieved based on patients as well as an interdisciplinary group of specialists. Rasch and internal consistency reliability analyses were implemented. The questionnaire included the modified ACR criteria main items (Symptom Severity Score and Widespread Pain Index), in addition to assessment of functional disability, quality of life (QoL), review of the systems, and comorbidities. Every patient completed HAQ and EQ-5D questionnaires. Results. A total of 146 fibromyalgia patients completed the questionnaire. The PROMs-FM questionnaire was reliable as demonstrated by a high standardized alpha (0.886-0.982). Content construct assessment of the functional disability and QoL revealed significant correlation (p < 0.01) with both HAQ and EQ-5D. Changes in functional disability and QoL showed significant (p < 0.01) variation with diseases activity status in response to therapy. There was higher prevalence of autonomic symptoms, CVS risk, sexual dysfunction, and falling. Conclusions. The developed PROMs-FM questionnaire is a reliable and valid instrument for assessment of fibromyalgia patients. A phased treatment regimen depending on the severity of FMS as well as preferences and comorbidities of the patient is the best approach to tailored patient management.

Psychosocial Work Environment and Musculoskeletal Symptoms among 21-Year-Old Workers: A Population-Based Investigation (2011-2013)

Background

The current labour market is becoming more flexible and informal, with job insecurity selectively affecting young workers. However, the role of these increasing adverse psychosocial working conditions on health outcomes remains little known among newly employed workers.

Objective

To estimate the associations between psychosocial work environment and musculoskeletal outcomes (widespread pain syndrome features and regional pain) in a population-based sample of young workers.

Methods

Cross-sectional data from workers aged 21 years were collected during the third wave of the EPITeen cohort study (2011-2013; n=650). The Job Content Questionnaire was used to characterize the psychosocial work environment according to the demand-control-support model. Data on pain and non-pain dimensions of the widespread pain syndrome (Fibromyalgia Survey Questionnaire) as well as on regional musculoskeletal pain (Nordic Musculoskeletal Questionnaire) were also collected. Crude and adjusted odds ratios (OR) with 95% confidence intervals (95% CI) were computed using logistic regression and all estimates were adjusted for sex, education and occupational biomechanical demands.

Results

Job insecurity was significantly associated to the non-pain dimension of the widespread pain syndrome (adjusted OR [95% CI]=1.51 [1.08, 2.12]). Young workers with strain jobs were significantly more likely to report high levels of non-pain symptoms when compared with those with no-strain jobs and this effect was even stronger when social support was added to the main exposure: workers with strain jobs and low social support had twice the odds of reporting high levels of non-pain features than those with high strain but high social support jobs (adjusted OR=1.86, 95% CI: 1.04, 3.31). These significant associations were not observed when widespread pain or multisite regional pain were the outcomes.

Conclusion

In the beginning of professional life, high strain jobs were associated to non-pain complaints, especially when the work environment provided also low social support.