Validity and Diagnosis in Physical and Rehabilitation Medicine: Critical View and Future Perspectives.

ABSTRACT: Obtaining a diagnosis is an essential and integral part of physical and rehabilitation medicine in practice and research. Standardized psychometric properties are required of any classifications, diagnostic criteria, and diagnostic rules used. Physicians and researchers, in physical and rehabilitation medicine, need to understand these properties to determine the accuracy and consistency of their diagnosis. Although chronic musculoskeletal pain disorders are among the highly prevalent disorders seen in physical and rehabilitation medicine, limitations regarding existing diagnostic criteria for chronic musculoskeletal pain disorders still exist. Hence, the quest for developing diagnostic tools for chronic musculoskeletal pain that align with the standard properties remains open. These are discussed with an example for existing diagnostic criteria for fibromyalgia. This article primarily aimed to provide an overview of standard psychometric properties. A secondary aim was to critically appraise the tools currently used to diagnose chronic musculoskeletal pain disorders. The challenges and limitations of existing diagnostic tools are discussed. Potential approaches on how to improve the conceptualization of the construct of musculoskeletal pain disorders are also discussed. Adopting a network perspective, for example, can better constitute the disease instead of a single known underlying etiology for persistent or recurrent pain symptoms.

¿Qué evidencia científica tienen los métodos propuestos para valorar la discapacidad laboral de los pacientes con síndrome de sensibilización central? / What scientific evidence do the current classifications have in order to assess occupational disability in patients with central sensitisation syndrome?

El síndrome de sensibilización central engloba enfermedades como la fibromialgia, el síndrome de fatiga crónica, la sensibilidad química múltiple y el síndrome de sensibilidad electromagnética. Estas afecciones han ido adquiriendo relevancia tanto médica como social por el aumento de la prevalencia, la ausencia de un tratamiento curativo, las limitaciones que provocan y los altos costes sanitarios que suponen. Además, todas ellas comparten una etiología desconocida y la ausencia de parámetros objetivos para establecer su diagnóstico y su gravedad. Se han propuesto múltiples métodos y clasificaciones para graduar la discapacidad de estos pacientes, pero en la actualidad ninguno de ellos ha conseguido una evidencia científica suficiente

Central sensitisation syndrome includes disorders such as fibromyalgia, chronic fatigue syndrome, multiple chemical sensitivity, and electromagnetic sensitivity syndrome. These disorders have been acquiring both medical and social relevance due to the increase in prevalence, the absence of a curative treatment, the limitations they cause, and the high healthcare costs they involve. Furthermore, all of them share an unknown aetiology and the absence of objective parameters to establish their diagnosis and severity. Multiple methods and classifications have been proposed to graduate the disability of these patients, but currently none of them have obtained sufficient evidence

[Non-inflammatory muscle pain]. / Nichtentzündliche Muskelschmerzen.

Muscle pain as a common symptom in daily practice frequently occurs as a non-specific accompanying symptom in multiple internal and neurological diseases. Primarily inflammatory or autoimmune muscular diseases are causing muscle pain. However, a number of non-inflammatory causes of pain can also be considered for differential diagnosis. These are presented in this article. In principle, a distinction must be made between focal and diffuse muscle pain. As an invasive diagnostic procedure, a muscle biopsy should only be performed as the last step in the diagnostic alogorithm. If diffuse muscle pain is only associated with slight muscle weakness or is completely absent, there is usually a primary rheumatic cause. Statins (HMG-CoA reductase inhibitors) can lead to rhabdomyolysis, muscle fiber atrophy and muscle necrosis by damaging the muscle fiber membrane. Myotonias are autosomal dominant or autosomal recessive inherited disorders of muscle function. The genetic defect leads to pronounced muscle stiffness. The cause of metabolic myopathies can be disorders of the carbohydrate, fat or purine metabolism. Fibromyalgia syndrome (FMS) is a non-inflammatory disease and, according to the current knowledge, recognized as the result of an exposure to physical, biological and psychosocial factors (biopsychological disease model). To help diagnosing FMS, pain regions and core symptoms (fatigue, sleep disturbances) can be detected using questionnaires (Widespread Pain Index [WPI] and Symptom Severity Scale [SSS]).

The prevalence of fibromyalgia in axial spondyloarthritis.

Comorbid fibromyalgia, in axial spondyloarthritis (axSpA) has been shown to influence disease activity and function, and quality of life. Although several papers exist, there is no comprehensive and robust systematic review to determine the prevalence of fibromyalgia in this patient group. Thus, the aim of the current study was to provide a definitive estimate of prevalence of fibromyalgia in axSpA, and in axSpA sub-classifications. A systematic literature search was conducted in Ovid MEDLINE, EMBASE, Evidence Based Medicine (EBM), and Cochrane Library, updated to April 2020, combining keywords and relevant MeSH headings, to identify papers reporting the prevalence of fibromyalgia in axSpA, or data from which this could be computed. This was then combined in a meta-analysis with data from the Scotland Registry for Ankylosing Spondylitis (SIRAS), a national axSpA register in Scotland. Data was pooled using random or fixed effects models where heterogeneity was greater or lesser than 75%. From 3401 manuscripts initially identified, 15 papers were included in the final review, plus SIRAS, giving data from 16 separate sources. The prevalence of fibromyalgia, among a total of 5214 patients, was 16.4% (95% CI 12.3-20.5%). Prevalence varied with axSpA sub-classification: ankylosing spondylitis: 13.8% (9.1-18.6%); MRI positive non-radiographic axSpA 20.3% (6.5-34.1%); and 'clinical' disease: 11.1% (6.0-16.2%). Overall, around 1 in 6 patients with axSpA also meet criteria for fibromyalgia. While estimates from individual studies vary, comorbid fibromyalgia represents a considerable burden across all sub-classifications of axSpA. This emphasises that focusing management solely on inflammatory disease in this patient group is unlikely to yield optimal improvements in quality of life.

Fibromyalgia, Sjogren's & depression: linked?

Health care has become increasingly fragmented, partly due to advancing medical technology. Patients are often managed by various specialty teams when presenting with symptoms that could be manifestations of different diseases. Approximately one third of them are referred to specialists, at over half for outpatient appointments. Fatigue, pain, depression, dry mouth, headaches, and arthralgia are common complaints and frequently require referral to specialist physicians. Differential diagnoses include fibromyalgia (FM), Sjogren's syndrome (SS), and depression. Evaluations involve various sub-specialist especially physicians like those practicing pain management, rheumatology, and psychiatry. Thresholds for referring vary. Patients sometime feel lost in a 'medical maze'. Disagreement is frequent between specialties regarding management. Each discipline has its own diagnostic and treatment protocols and there is little consensus about shared decision-making. Communication between doctors could improve continuity. There are many differences and similarities in the pathophysiology, symptomatology, diagnosis, and treatment of fibromyalgia, Sjogren's syndrome, and depression. Understanding the associations between fibromyalgia, Sjogren's syndrome and depression should improve clinical outcome via a common holistic approach.

Diagnosis of fibromyalgia: comparison of the 2011/2016 ACR and AAPT criteria and validation of the modified Fibromyalgia Assessment Status.

OBJECTIVE: To compare the concordance of the three diagnostic criteria, respectively the 2011 ACR criteria (ACR 2011 Cr), the ACR 2016 criteria (ACR 2016 Cr) and the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION)-APS Pain Taxonomy criteria (AAPT Cr), and to explore the performance of an additional set of criteria, the modified Fibromyalgia Assessment Status (FAS 2019 modCr), in the diagnosis of FM syndrome. METHODS: Consecutive patients with chronic widespread pain, referred by the primary care setting, underwent rheumatologic assessment that established the presence or not of FM and were investigated through the four sets of proposed criteria. For the FAS 2019 modCr, discriminant validity to distinguish patients with FM and non-FM was assessed with receiver operating characteristic curve analysis. RESULTS: A total of 732 (405 with FM and 327 with other common chronic pain problems) patients were evaluated. Against the clinical diagnosis of FM, the sensitivity, specificity and correct classification were, respectively: 79.8, 91.7 and 85.1% for ACR 2011 Cr; 78, 90.5 and 83.6% for the ACR 2016 Cr; and 73.8, 91.7 and 81.8% for the AAPT Cr. The alternative set, proposed on the FAS 2019 modCr, provided a maximal diagnostic accuracy with a score ≥20 (Youden's index), with a sensitivity of 84.2%, specificity 89.0% and positive likelihood ratio 7.65. CONCLUSION: There is a considerable agreement between criteria-based diagnoses of FM, although the AAPT Cr perform least well in terms of percentage of correct classification. The FAS 2019 modCr had comparable characteristics.

Subgrouping a Large U.S. Sample of Patients with Fibromyalgia Using the Fibromyalgia Impact Questionnaire-Revised.

Fibromyalgia (FM) is a heterogeneous and complex syndrome; different studies have tried to describe subgroups of FM patients, and a 4-cluster classification based on the Fibromyalgia Impact Questionnaire-Revised (FIQR) has been recently validated. This study aims to cross-validate this classification in a large US sample of FM patients. A pooled sample of 6280 patients was used. First, we computed a hierarchical cluster analysis (HCA) using FIQR scores at item level. Then, a latent profile analysis (LPA) served to confirm the accuracy of the taxonomy. Additionally, a cluster calculator was developed to estimate the predicted subgroup using an ordinal regression analysis. Self-reported clinical measures were used to examine the external validity of the subgroups in part of the sample. The HCA yielded a 4-subgroup distribution, which was confirmed by the LPA. Each cluster represented a different level of severity: "Mild-moderate", "moderate", "moderate-severe", and "severe". Significant differences between clusters were observed in most of the clinical measures (e.g., fatigue, sleep problems, anxiety). Interestingly, lower levels of education were associated with higher FM severity. This study corroborates a 4-cluster distribution based on FIQR scores to classify US adults with FM. The classification may have relevant clinical implications for diagnosis and treatment response.

Revised chronic widespread pain criteria: development from and integration with fibromyalgia criteria.

Background and aims Persons with chronic widespread pain (CWP) have poor medical outcomes and increased mortality. But there are no universally accepted criteria for CWP or of methods to assess it. The most common criteria come from the 1990 American College of Rheumatology (ACR) fibromyalgia (FM) criteria, but that method (WP1990) can identify CWP with as few as three pain sites, and in subjects with wide differences in illness severity. Recently, to correct WP1990 deficiencies, the 2016 fibromyalgia criteria provided a modified CWP definition (WP2016) by dividing the body into five regions of three pain sites each and requiring a minimum of four regions of pain. Although solving the geographic problem of pain distribution, the problem of just how many pain sites (pain diffuseness) are required remained a problem, as WP2016 required as few as four painful sites. To better characterize CWP, we compared four CWP definitions with respect to symmetry, extent of pain sites and association with clinical severity variables. Methods We characterized pain in 40,960 subjects, including pain at 19 individual sites and five pain regions, and calculated the widespread pain index (WPI) and polysymptomatic distress scales (PDS) from epidemiology, primary care and rheumatology databases. We developed and evaluated a new definition for CWP, (WP2019), defined as pain in four or five regions and a pain site score of at least seven of 15 sites. We also tested a definition based on the number of painful sites (WPI ≥ 7). Results In rheumatology patients, WP1990 and WPI ≥ 7 classified patients with <4 regions as WSP. CWP was noted in 51.3% by WP1990, 41.7% by WP2016, 37.6% of WPI ≥ 7 and 33.9% by WP2019. 2016 FM criteria was satisfied in WP1990 (51.1%), WP2016 (63.3%), WPI ≥ 7 (69.0%) and WP2019 (76.6%). WP2019 positive patients had more severe clinical symptoms compared with WP1990, WP2016 and WPI ≥ 7, and similar to but less than FM 2016 positive patients. In stepwise fashion, scores for functional disability, visual analog scale fatigue and pain, WPI, polysymptomatic distress score and Patient Health Questionnaire 15 (PHQ-15) worsened from WP1990 through WP2016, WPI ≥ 7 and WP2019. Conclusions WP2019 combines the high WPI scores of WPI ≥ 7 and the symmetry of WP2016, and is associated with the most abnormal clinical scores. The WP1990 does not appear to be an effective measure. We suggest that CWP can be better defined by combining 4-region pain and a total pain site score ≥7 (WP2019). This definition provides a simple, unambiguous measure that is suitable for clinical and research use as a standalone diagnosis that is integrated with fibromyalgia definitions. Implications Definitions of CWP in research and clinic care are arbitrary and have varied, and different definitions of CWP identify different sets of patients, making a universal interpretation of CWP uncertain. In addition, CWP is a mandatory component of some fibromyalgia criteria. Our study provides quantitative data on the differences between CWP definitions and their criteria, allowing better understanding of research results and a guide to the use of CWP in clinical care.

Relationship of Depression Scores and Ranges in Women Who Suffer From Fibromyalgia by Age Distribution: A Case-Control Study.

BACKGROUND: Fibromyalgia may be defined as a chronic widespread pain condition that generates a functional impairment with various symptoms, such as depression. PURPOSE: The main aim of this research was to compare the Beck Depression Inventory (BDI) scores and depression ranges in women who suffered from fibromyalgia with respect to healthy controls, overall and by age distributions. METHODS: A case-control observational study was performed. Two hundred women with a mean age of 58.61 ± 15.65 years old were recruited. The women were divided into case (women with fibromyalgia) and control (healthy women) groups. The BDI scores and depression ranges were collected. RESULTS: The depression ranges and BDI scores mean ± SD showed statistically significant differences (p < .001) between participants with fibromyalgia (19.30 ± 11.21 points; moderate depression) and healthy controls (6.37 ± 5.35 points; no depression). Regarding the age distributions, statistically significant differences were shown between fibromyalgia and control groups for adults (p < .001; 19.06 ± 6.55 vs. 4.69 ± 4.48 points) and older adults (p = .001; 20.25 ± 13.79 vs. 7.63 ± 5.47 points), respectively. ANOVA of the BDI scores with two factors and interaction (fibromyalgia presence and age distribution) determined no interaction between the two factors (p = .534) and statistically significant differences of BDI scores for fibromyalgia presence (p < .001; R2  = 35.50%), but not for age distribution (p = .144). LINKING EVIDENCE TO ACTION: Measurable differences in higher BDI scores and depression ranges were shown in women who suffered from fibromyalgia with respect to healthy controls, regardless of age distribution. Greater probabilities (odds ratio = 15.88) of suffering from some level of depression (according to BDI scores) were found in women with fibromyalgia in comparison with healthy women. Although these findings did not seem to be influenced by age distribution, interventions targeting depression in practice, research, policy, management, or education must equally include adult and older adult women who suffer from fibromyalgia.

Binary Classification Using Neural and Clinical Features: An Application in Fibromyalgia With Likelihood-Based Decision Level Fusion.

Among several features used for clinical binary classification, behavioral performance, questionnaire scores, test results, and physical exam reports can be counted. Attempts to include neuroimaging findings to support clinical diagnosis are scarce due to difficulties in collecting such data, as well as problems in integration of neuroimaging findings with other features. The binary classification method proposed here aims to merge small samples from multiple sites so that a large cohort, which better describes the features of the disease can be built. We implemented a simple and robust framework for detection of fibromyalgia, using likelihood during decision level fusion. This framework supports sharing of classifier applications across clinical sites and arrives at a decision by fusing results from multiple classifiers. If there are missing opinions from some classifiers due to inability to collect their input features, such degradation in information is tolerated. We implemented this method using functional near infrared spectroscopy (fNIRS) data collected from fibromyalgia patients across three different tasks. Functional connectivity maps are derived from these tasks as features. In addition, self-reported clinical features are also used. Five classifiers are trained using k nearest neighborhood (kNN), linear discriminant analysis (LDA), and support vector machine (SVM). Fusion of classification opinions from multiple classifiers based on likelihood ratios outperformed individual classifier performances. When 2, 3, 4, and 5 different classifiers are fused, sensitivity, and specificity figures of 100% could be obtained based on the choice of the classifier set.

Chronic Widespread Pain in a tertiary pain clinic: classification overlap and use of a patient generated quality of life instrument.

Background and aims This study has two main aims: (1) To explore the overlap between classification criteria in patients with Chronic Widespread Pain (CWP) and (2) To explore the use of the Patient Generated Index (PGI) as a quality of life (QoL) measure in this patient group. Methods Patients with Widespread Pain (ICD-11: pain in four or more out of five bodily regions, i.e. the four quadrants and axially) in a tertiary pain outpatient clinic were assessed according to classification criteria for Fibromyalgia [FM, American College of Rheumatology (ACR) criteria of 1990, 2010, 2011 and 2016], Chronic Fatigue Syndrome [CFS, Fukuda, Canada and International Consensus Criteria (ICC)] and Bodily Distress Syndrome (BDS). Furthermore, patients completed the PGI to assess QoL, and electronic questionnaires including demographic variables and standardised patient-reported outcome measures (PROMs). Results All patients (n=33) fulfilled the criteria for musculoskeletal type single-organ BDS, 81.8% met the 2016 modified criteria for FM, 30.3% met the Canada criteria for CFS and 24.2% met the criteria for multi-organ type BDS. There was substantial agreement between the 2016 and the 2011 and 2010 criteria sets for FM compared to the 1990 criteria (κ=0.766 and 0.673 compared to 0.279). Patients generally scored low on the PGI, indicating poor QoL (mean PGI 28.9, SD 19.8, range 0-100). Conclusions Our findings support the use of the term musculoskeletal type single-organ BDS to describe patients with CWP and the 2016 revision of the FM criteria. The PGI provides useful clinical information which is not captured by standardised PROMs. Implications The terminology of CWP has become less ambiguous as the new ICD-11 is closely related to the generalised pain criterion of the modified 2016 FM definition. Studies based on the 1990 classification criteria for FM should not be directly compared to studies based on later criteria set. The PGI may be a supplement to other measurements to portray patients' individual concerns in patients with complex symptom disorders.

Categorisation of disease severity states in fibromyalgia: a first step to support decision-making in health care policy.

OBJECTIVES: To establish the cut-off points for disease severity states of two self-administered questionnaires (the revised version of the Fibromyalgia-Impact Questionnaire [FIQR] and the Fibromyalgia Assessment Status [FAS]) designed for the evaluation of multidimensional aspects of fibromyalgia (FM). METHODS: In this cross-sectional study, consecutive FM patients completed both FIQR and FAS. The external criterion for grading disease severity was the item one of the Short Form-36 Health Survey (SF-36). The reconciliation approach of the 75th-25th percentiles of adjacent ranks was applied to establish cut-off points distinguishing between disease activity states. RESULTS: 521 FM patients (80.0% women, mean age 49 years) completed the assessment. The overall mean (standard deviation [SD]) FIQR and FAS were 47.87 (SD 20.69) and 5.57 (SD 2.09), respectively. The highest FIQR scored items were those related to sleep quality, fatigue/energy, pain, stiffness, tenderness, and environmental sensitivity. With the reconciliation of 75th-25th percentiles of adjacent ranks, the FIQR cut-off points obtained were: remission ≤30, mild severity >30 and ≤45, moderate severity >46 and ≤65, high severity >65. The same approach for FAS leaded to: remission ≤4, mild severity >4 and ≤5.5, moderate severity >5.6 and ≤7.0, high severity >7.0. The majority of the subjects was classified as suffering from a moderate (FIQR 28.4%; FAS 23.2%) or severe (FIQR 24.4%; FAS 30.7%) FM. CONCLUSIONS: The FIQR and FAS cut-off points for remission, mild, moderate and high disease severity are valid measures which can be easily applied in daily clinical practice.

Longitudinal stability of fibromyalgia symptom clusters.

BACKGROUND: Using self-report questionnaires of key fibromyalgia symptom domains (pain, fatigue, sleep disturbance, function, stiffness, dyscognition, depression, and anxiety), we previously identified four unique symptom clusters. The purpose of this study was to examine the stability of fibromyalgia symptom clusters between baseline and 2-year follow-up. METHODS: Women with a diagnosis of fibromyalgia completed the Brief Pain Inventory, Profile of Mood States, Medical Outcomes Study Sleep measure, Multidimensional Fatigue Inventory, Multiple Ability Self-Report Questionnaire, Revised Fibromyalgia Impact Questionnaire, and the 36-Item Short Form Survey Instrument at baseline. Follow-up measures were completed approximately 2 years later. The hierarchical agglomerative clustering algorithm previously developed was applied; agreement between baseline and follow-up was assessed with the κ statistic. RESULTS: Among 433 participants, the mean age was 56 (range 20-85) years. The median Revised Fibromyalgia Impact Questionnaire total score was 57 (range 8-96). More than half of participants (58%) remained in the same cluster at follow-up as at baseline, which represented moderate agreement between baseline and follow-up (κ = 0.44, 95% confidence interval (CI) 0.37-0.50). Only two patients changed from high symptom intensity to low symptom intensity; similarly, only three moved from low to high. CONCLUSIONS: Fibromyalgia patients classified into four unique symptom clusters based on the key domains of pain, fatigue, sleep disturbance, function, stiffness, dyscognition, depression, and anxiety showed moderate stability in cluster assignment after 2 years. Few patients moved between the two extremes of severity, and it was slightly more common to move to a lower symptom level than to worsen. TRIAL REGISTRATION: Not applicable.

Symptoms of Fibromyalgia According to the 2016 Revised Fibromyalgia Criteria in Chronic Pain Patients Referred to Multidisciplinary Pain Rehabilitation: Influence on Clinical and Experimental Pain Sensitivity.

Fibromyalgia (FM) is a condition with chronic widespread pain and signs of generalized pain hypersensitivity. FM has previously been classified according to the American College of Rheumatology-1990 criteria, where the presence of hypersensitivity is estimated by a tender point examination. Because of the limitations of these classification criteria, new diagnostic criteria have been proposed, abandoning this examination. This cross-sectional study investigated the prevalence of FM according to the revised 2016 FM criteria in a large cohort of chronic pain patients. Pain drawings, the FM Symptom Severity Scale, and questionnaires assessing manifestations of pain, pain-related disability, and psychological distress were collected from 1,343 patients with chronic nonmalignant pain referred to a multidisciplinary pain clinic. In addition, assessments of mechanical and thermal pain sensitivity were performed in 496 of the patients. Patients fulfilling the FM criteria (n = 498, 37%) reported significantly higher levels of pain, pain-related disability, psychological distress, and sensitivity to mechanical and heat stimuli (P < .05). Moreover, the proportion using opioids were significantly higher compared with patients not fulfilling the criteria (P = .015). Significant associations were found between heat and mechanical pain sensitivity (P < .001) indicating that patients who showed higher pain sensitivity to mechanical stimulation also showed higher pain sensitivity to thermal stimulation. PERSPECTIVE: More than one-third of patients were classified as FM, and patients classified showed increased clinical and experimental pain profiles. Because no data were collected on whether the included patients had a clinical FM diagnosis, future studies validating the American College of Rheumatology-2016 criteria in a cohort of patients with chronic nonmalignant pain are warranted.

Pain and Fatigue Variability Patterns Distinguish Subgroups of Fibromyalgia Patients.

The current study examined between- and within-subject variability in pain-related symptoms as predictors of pain and fatigue, and identified patient subgroups on the basis of symptom variability characteristics. Two hundred fifty-six fibromyalgia (FM) patients completed daily diaries up to a period of 154 days and reported on symptoms of pain intensity, pain unpleasantness, fatigue, anxiety, and depressed mood. Measures of health status, quality of life, and somatic symptoms were obtained at baseline, and hierarchical linear modeling and cluster analyses were used. Significant intra- and interindividual variability in daily FM symptoms was observed. Higher levels of pain were associated with greater fluctuations in pain unpleasantness, fatigue, and depressed mood. Similar effects were observed for fatigue and individual variability in anxiety also emerged as a robust predictor. Three FM subgroups were revealed: low variability in symptoms (cluster 1), high symptom variability (cluster 2), and a mixed variability group characterized by low fluctuation in pain unpleasantness; moderate pain, fatigue, and depressed mood variability; and high anxiety variability (cluster 3). Cluster 3 exhibited lower social functioning and higher levels of pain, compared with cluster 1. These findings support the dynamic nature of FM pain and suggest the presence of FM subgroups on the basis of variation in mood and pain symptomatology. PERSPECTIVE: FM patients show significant intra- and interindividual variability in pain, mood, and fatigue. Subgroups in mood and pain-related variability emerged, with phenotypic clusters differing across levels of pain intensity and social functioning. Better understanding of the processes affecting pain variability may facilitate targeted treatments for the control of pain.

Patients with fibromyalgia rarely fulfil classification criteria for axial spondyloarthritis.

Background: The Assessments of Spondyloarthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) have been criticized because of insufficient differentiation towards FM. The aim of this study was to compare the performance of currently used classification criteria in patients diagnosed with axSpA or FM. Methods: Patients were prospectively included if diagnosed with axSpA or FM by the treating rheumatologist and evaluated by an independent examiner for fulfilment of the classification criteria for axSpA (ASAS criteria) and/or FM (1990 ACR classification and 2010 ACR diagnostic criteria). Patients with axSpA were stratified based on classification as non-radiographic axSpA (nr-axSpA) or AS. Symptom severity was assessed by established disease-related questionnaires. Results: Overall, 300 patients were included, 100 with FM and 200 with axSpA of which 100 each had nr-axSpA and AS. Almost all FM patients fulfilled the 2010 (100%) and 1990 ACR criteria (98%) for FM, but only 2% fulfilled the ASAS criteria. When calculations were based on only the FM patients with available HLA-B27 results (n = 40), the proportion fulfilling the ASAS criteria was 5%. All axSpA patients met the ASAS criteria but also the 2010 (24%) and 1990 (13.5%) FM criteria. More patients with AS (29% and 19%) than with nr-axSpA (19% and 8%) fulfilled the 2010 and 1990 FM criteria, respectively. Conclusion: FM patients only rarely fulfil classification criteria for axSpA but some axSpA patients also fulfil FM criteria. Since this was more frequent in patients with AS it may be related to the severity and duration of chronic pain in axSpA patients. Assessment instruments evaluated in axSpA are not disease-specific. The phenomenon of central pain sensitization in rheumatic diseases deserves more study.

[Etiology and pathophysiology of fibromyalgia syndrome : Updated guidelines 2017, overview of systematic review articles and overview of studies on small fiber neuropathy in FMS subgroups]. / Ätiologie und Pathophysiologie des Fibromyalgiesyndroms : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten sowie eine Übersicht über Studien zur Kleinfaserpathologie bei Subgruppen des FMS.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was planned for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A systematic search of the literature from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Prospective population-based studies and systematic reviews with meta-analyses of case control studies were taken into consideration for the statements. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The statements were generated by multiple step formalized procedures. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS: Current data do not enable identification of distinct factors in the etiology and pathophysiology of fibromyalgia syndrome. Fibromyalgia syndrome can be associated with inflammatory rheumatic diseases, gene polymorphisms, life style factors (e.g. smoking, obesity and lack of physical activity), depressive disorders as well as physical and sexual abuse in childhood and adulthood. CONCLUSION: Fibromyalgia syndrome is most probably the end result of various pathogenetic factors and pathophysiological mechanisms.

[General treatment principles, coordination of care and patient education in fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Allgemeine Behandlungsgrundsätze, Versorgungskoordination und Patientenschulung beim Fibromyalgiesyndrom : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A search of the literature for systematic reviews on randomized, controlled trials on patient education and shared decision-making from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. Efficacy, risks, patient preferences, clinical and practical applicability of available therapies were weighed up against each other. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: The diagnosis of fibromyalgia syndrome should be explicitly communicated to the affected individual. Shared decision-making with the patient on the therapeutic options based on individual preferences of the patient, comorbidities and the success of previous treatment is recommended. A step-wise treatment approach depending on the severity of fibromyalgia syndrome and the response to therapeutic measures is recommended.

[Definition, classification, clinical diagnosis and prognosis of fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Definition, Klassifikation, klinische Diagnose und Prognose des Fibromyalgiesyndroms : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A systematic search of the literature from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: The clinical diagnosis of fibromyalgia syndrome can be established by the American College of Rheumatology (ACR) 1990 classification criteria (with examination of tender points) or without the examination of tender points by the modified preliminary diagnostic ACR 2010 or 2011 criteria.