Cost of illness in inclusion body myositis: results from a cross-sectional study in Germany.

BACKGROUND: Inclusion body myositis (IBM) is the most frequent type of myositis in elder patients with a slow chronic progression and refractory to treatment. Previous cost of illness (COI) studies in IBM used claims data to estimate direct costs in the US. No evidence exists globally on both direct and indirect costs in IBM from a societal perspective. We conducted a survey in patients registered in the German IBM patient registry. Self-developed items were used to assess the utilized healthcare resources and estimate the cost. The German Self-Administered Comorbidity Questionnaire (SCQ-D), the sIBM Physical Functioning Assessment (sIFA) and patient-reported measures for satisfaction and improvements in healthcare were applied for an explorative analysis. RESULTS: In total, 82 patients completed the survey. We estimated the mean total annual per capita COI of US$102,682 (95% CI US$82,763-US$123,090) in 2021. 92.7% of the total COI were direct costs. Medical costs were similar to nonmedical costs, with substantial costs for pharmacotherapy and informal care. Depending on the prevalence estimate, the total national COI per year were US$42.7 million-US$213.7 million. Significant differences in total COI were identified for the degree of disability, marital and employment status (p < 0.05). CONCLUSIONS: We identified remarkable and heterogenous cost in IBM. As informal care costs represented the most relevant cost driver, caregiver burden is a major factor in the patient journey. For the first time, comprehensive economic potentials were identified as a basis to improve the actual care situations and prioritizing future activities for research, pharmaceutical and digital product development as well as health politics.

Inclusion body myositis with early onset: a population-based study.

INTRODUCTION: Inclusion body myositis (IBM), an inflammatory myopathy with progressive weakness without efficient treatment, typically presents after 45 years of age and younger patients are sparsely studied. METHODS: In a population-based study during a 33-year period, 142 patients with IBM were identified in western Sweden. Six patients fell outside the European Neuromuscular Centre 2011 criteria for IBM due to young age at symptom onset, verified by a muscle biopsy < 50 years of age. These were defined as early-onset IBM and included in this study. Medical records, muscle strength, comorbidities, muscle biopsies, and nuclear- and mitochondrial DNA were examined and compared with patients with IBM and age matched controls from the same population. RESULTS: The median age at symptom onset was 36 (range 34-45) years and at diagnosis 43 (range 38-58) years. Four patients were deceased at a median age of 59 (range 50-75) years. The median survival from diagnosis was 14 (range 10-18) years. The prevalence December 31 2017 was 1.2 per million inhabitants and the mean incidence 0.12 patients per million inhabitants and year. The mean decline in quadriceps strength ± 1 standard deviation was 1.21 ± 0.2 Newton or 0.91 ± 0.2% per month and correlated to time from diagnosis (p < 0.001). Five patients had swallowing difficulties. All patients displayed mitochondrial changes in muscle including cytochrome c oxidase deficiency and the mitochondrial DNA mutation load was high. CONCLUSIONS: Early-onset IBM is a severe disease, causing progressive muscle weakness, high muscle mitochondrial DNA mutation load and a reduced cumulative survival in young and middle-aged individuals.

Inclusion body myositis: evolving concepts.

PURPOSE OF REVIEW: To discuss recent developments in our understanding of epidemiology, diagnostics, biomarkers, pathology, pathogenesis, outcome measures, and therapeutics in inclusion body myositis (IBM). RECENT FINDINGS: Recent epidemiology data confirms a relatively higher prevalence in the population aged above 50 years and the reduced life expectancy. Association with cancer and other systemic disorders is better defined. The role of magnetic resonance imaging (MRI) and ultrasound in diagnosis as well as in following disease progression has been elucidated. There are new blood and imaging biomarkers that show tremendous promise for diagnosis and as outcome measures in therapeutic trials. Improved understanding of the pathogenesis of the disease will lead to better therapeutic interventions, but also highlights the importance to have sensitive and responsive outcome measures that accurately quantitate change. SUMMARY: There are exciting new developments in our understanding of IBM which should lead to improved management and therapeutic options.

Epidemiology, Survival, and Clinical Characteristics of Inclusion Body Myositis.

OBJECTIVE: We performed a population-based study on inclusion body myositis with the primary aims to define the prevalence, survival rate, and incidence, and to investigate the symptom profiles associated with disease duration and sex over a 33-year period. METHODS: Patients diagnosed between 1985 and 2017 in Region Västra Götaland, Sweden, were identified according to the European Neuromuscular Centre diagnostic criteria from 2011. RESULTS: We identified 128 patients, 89 men and 39 women, with the strict clinicopathological definition of inclusion body myositis. The prevalence was 32 per million inhabitants, 19 per million women and 45 per million men, by December 31, 2017. Mean incidence was 2.5 per million inhabitants and year. Mean age at symptom onset was 64.4 years with quadriceps weakness being the most common presenting symptom followed by finger flexor weakness. Dysphagia was a common presenting symptom being more frequent in women (23%) than men (10%) and was during the disease course reported in 74% of men and 84% of women. Seventy-three patients were deceased, with a mean survival of 14 years from symptom onset. Survival rates from both diagnosis date and symptom onset were decreased compared to the matched population. Twenty-one percent of the patients had an additional autoimmune disease. A cross-sectional analysis of autoantibodies in 50 patients and 28 matched controls showed autoantibodies to cytosolic 5'-nucleotidase 1A in 40% of the patients and 3.6% of controls. INTERPRETATION: Inclusion body myositis is an autoimmune disease with decreased survival rate and with marked sex differences in both prevalence and clinical manifestations. ANN NEUROL 2022;92:201-212.

Survival and associated comorbidities in inclusion body myositis.

OBJECTIVE: To evaluate survival and associated comorbidities in inclusion body myositis (IBM) in a population-based, case-control study. METHODS: We utilized the expanded Rochester Epidemiology Project medical records-linkage system, including 27 counties in Minnesota and Wisconsin, to identify patients with IBM, other inflammatory myopathies (IIM), and age/sex-matched population-controls. We compared the frequency of various comorbidities and survival among groups. RESULTS: We identified 50 IBM patients, 65 IIM controls and 294 population controls. Dysphagia was most common in IBM (64%) patients. The frequency of neurodegenerative disorders (dementia/parkinsonism) and solid cancers was not different between groups. Rheumatoid arthritis was the most common rheumatic disease in all groups. A total of 36% of IBM patients had a peripheral neuropathy, 6% had Sjögren's syndrome and 10% had a haematologic malignancy. T-cell large granular lymphocytic leukaemia was only observed in the IBM group. None of the IBM patients had hepatitis B or C, or HIV. IBM patients were 2.7 times more likely to have peripheral neuropathy, 6.2 times more likely to have Sjögren's syndrome and 3.9 times more likely to have a haematologic malignancy than population controls. IBM was associated with increased mortality, with a 10-year survival of 36% from index, compared with 67% in IIM and 59% in population controls. Respiratory failure or pneumonia (44%) was the most common cause of death. CONCLUSIONS: IBM is associated with lower survival, and higher frequency of peripheral neuropathy, Sjögren's syndrome and haematologic malignancies than the general population. Close monitoring of IBM-related complications is warranted.

Epidemiology and Natural History of Inclusion Body Myositis: A 40-Year Population-Based Study.

OBJECTIVES: To determine the prevalence and natural history of sporadic inclusion body myositis (sIBM) and to test the hypothesis that patients with sIBM have higher cancer or mortality rates than the general population. METHODS: We sought patients with sIBM defined by the 2011 European Neuromuscular Centre (ENMC) diagnostic criteria among Olmsted County, Minnesota, residents in 40-year time period. RESULTS: We identified 20 patients (10 clinicopathologically defined, 9 clinically defined, and 1 probable) according to the ENMC criteria and 1 patient with all features of clinicopathologically defined sIBM except for symptom onset at <45 years of age. The prevalence of sIBM in 2010 was 18.20 per 100,000 people ≥50 years old. Ten patients developed cancers. The incidence of cancers in sIBM did not differ from that observed in the general population (odds ratio 1.89, 95% confidence interval [CI] 0.639-5.613, p = 0.24). Two-thirds of patients developed dysphagia, and half required a feeding tube. Nine patients required a wheelchair. The median time from symptom onset to wheelchair dependence was 10.5 (range 1-29) years. Overall life expectancy was shorter in the sIBM group compared to the general population (84.1 [95% CI 78-88.4] vs 87.5 [95% CI 85.2-89.5] years, p = 0.03). Thirteen patients died; 9 deaths were sIBM related (7 respiratory and 2 unspecified sIBM complications). Female sex (p = 0.03) and dysphagia (p = 0.05) were independent predictors of death. CONCLUSION: Olmsted County has the highest prevalence of sIBM reported to date. Patients with sIBM have similar risk of cancer, but slightly shorter life expectancy compared to matched patients without sIBM. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that patients with sIBM have similar risks of cancers and slightly shorter life expectancy compared to controls.

Inclusion body myositis in the rheumatology clinic.

Inclusion body myositis is a rare sporadic inflammatory-degenerative myopathy of the elderly. Despite being the commonest type of acquired myopathy after the age of 50, misdiagnosis is extremely common. The most frequent hurdle in identifying new cases is the wrong diagnosis of polymyositis or motor neuron disease. Novel insights into pathogenic mechanisms have heralded the quest for newer therapeutics as well as drug repurposing in this otherwise progressive disorder.

Association of Ultraviolet Radiation Exposure With Dermatomyositis in a National Myositis Patient Registry.

OBJECTIVE: Dermatomyositis (DM) has been associated with geospatial differences in ultraviolet (UV) radiation, but the role of individual determinants of UV exposure prior to diagnosis is unknown. The objective was to examine the role of those individual determinants. METHODS: We analyzed questionnaire data from 1,350 adults in a US national myositis registry (638 with DM, 422 with polymyositis [PM], and 290 with inclusion body myositis [IBM] diagnosed at ages 18-65 years), examining the likelihood of DM compared with PM and IBM diagnosis, in relation to self-reported sunburn history and job- and hobby-related sun exposures in the year prior to diagnosis. We estimated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression adjusted for age, skin tone, and sex, to determine the association of individual UV exposures with DM diagnosis. We also evaluated the proportion of DM by maximum daily ambient UV exposure, based on UVB erythemal irradiances for participant residence in the year prior to diagnosis. RESULTS: DM was associated with sunburn in the year before diagnosis (2 or more sunburns OR 1.77 [95% CI 1.28-2.43] versus PM/IBM; 1 sunburn OR 1.44 [95% CI 1.06-1.95]) and with having elevated job- or hobby-related sun exposure (high exposure OR 1.64 [95% CI 1.08-2.49] or moderate exposure OR 1.35 [95% CI 1.02-1.78] versus low or no exposure). Ambient UV intensity was associated with DM in females (ß = 3.97, P = 0.046), but not overall. CONCLUSION: Our findings suggest that high or moderate personal exposure to intense sunlight is associated with developing DM compared with other types of myositis. Prospective research on UV exposure as a modifiable risk factor for DM is warranted.

Health care costs and comorbidities for patients with inclusion body myositis.

OBJECTIVE: This study identifies the health care costs and utilization, as well as comorbidities, in a Medicare population of inclusion body myositis (IBM) patients. METHODS: Medicare patients aged ≥65 years with a diagnosis claim for IBM were identified and matched to a cohort of non-IBM patients based on age, sex, race, calendar year and census region. Generalized linear models were used to estimate health care costs and utilization during the follow-up period. RESULTS: The prevalence of IBM in this population, aged ≥65 years, was 83.7 cases per 1 million patients. Mean 1 year costs for the IBM cohort (N = 361) were $44,838 compared to $10,182 for the matched non-IBM cohort (N = 1805), an excess of $34,656. IBM was significantly associated with multiple unsuspected comorbidities, including hypertension (66% vs. 22%), hyperlipidemia (47% vs. 18%) and myocardial infarction (13% vs. 2%) (all p < .0001). CONCLUSIONS: IBM patients utilize more health care resources and incur higher health care costs than patients without IBM. Furthermore, IBM patients were more likely to have multiple comorbidities, including cardiovascular risk factors and events, muscle and joint pain, and pulmonary complications compared to those without IBM. LIMITATIONS: The presence of a diagnosis code for a condition on a medical claim does not necessarily indicate the presence of the disease condition because the diagnosis code could be incorrectly entered in the database. Clinical and disease-specific parameters were not available in the claims data. Additionally, due to the observational study design, the analysis may be affected by unobserved differences between patients.

Burden of illness and healthcare resource use in United States patients with sporadic inclusion body myositis.

INTRODUCTION: We analyzed the burden of illness of sporadic inclusion body myositis (sIBM) patients and the costs to the healthcare system. METHODS: A retrospective cohort analysis of 333 sIBM patients aged ≥ 50 years was performed using United States (U.S.) claims data. sIBM patients were matched in a 1:5 ratio to randomly selected individuals with ≥1 healthcare encounter within the year of index date. RESULTS: sIBM patients presented with higher rates of disease- and muscle-related conditions, such as myalgia, myositis, muscle weakness, dysphagia, pneumonia, and falls. Use of healthcare resources, including physical therapy, office visits, emergency room (ER) visits, and hospitalizations, was greater in sIBM patients. This was also reflected in significantly higher overall healthcare costs in the sIBM population driven mainly by more all-cause office visits, all-cause ER visits and hospitalizations. CONCLUSIONS: sIBM imposes a substantial burden on U.S. patients in terms of additional healthcare usage and associated costs. Muscle Nerve 56: 861-867, 2017.

A Systematic Review and Meta-Analysis of Prevalence Studies of Sporadic Inclusion Body Myositis.

BACKGROUND: Sporadic Inclusion Body Myositis (sIBM) is a rare and slowly progressive debilitating muscle disease with symptoms generally developing≥50 years of age. OBJECTIVE: To conduct a systematic review and meta-analysis of the prevalence of sIBM literature, including a methodological quality assessment of the selected papers. METHODS: A systematic search of Medline, Embase, Cochrane Database of Systematic Reviews and major Myositis and Neurological conferences was conducted. Articles reporting prevalence and published in English up to March 2017 were assessed for methodology quality using the Loney quality assessment, Downs & Black score, and the Methodological Evaluation of Observational Research checklists. Meta-analyses using random effects were completed on both general population and≥50 years prevalence estimates. RESULTS: 315 articles were retrieved and data were extracted from 10 relevant studies. One study was subsequently excluded due to methodological issues. The meta-prevalence estimate from 9 papers was 24.8/1,000,000 (95% CI: 20.0-29.6). The methodological quality results were consistent across assessment tools with four articles scoring 4 or 5 out of 8 in the Loney assessment. The meta-prevalence of these four articles was 45.6/ 1,000,000 (95% CI: 35.9-55.2). CONCLUSION: There was high variability in reported sIBM prevalence estimates and the quality of the studies conducted. Existing evidence suggests an increase of prevalence estimates over time, which may be explained by growing disease awareness, improvements in diagnostic criteria and study methodologies. Further high quality studies are needed to understand if prevalence varies across geographies or ethnicities.

Multicenter registry on inflammatory myositis from the Rheumatology Society in Madrid, Spain: Descriptive Analysis. / Registro de pacientes con miopatía inflamatoria de la Sociedad Madrileña de Reumatología: análisis descriptivo.

OBJECTIVE: To analyze clinical characteristics, survival and causes of death of patients diagnosed with autoimmune inflammatory myositis in the REMICAM registry from the Society of Rheumatology in the Community of Madrid (SORCOM). METHODS: Multicenter cohort of patients diagnosed with autoimmune inflammatory myopathy with follow-up between January 1980 and December 2014. A total of 313 variables concerning demographic, clinical and morbidity data were collected, and a comparison was performed between clinical subgroups. RESULTS: A total of 479 patients were recruited from 12 centers, with 14% of patients lost to follow-up. Seventy-four percent of cases were women, age at diagnosis of 44±23 years and a mean follow-up period of 10±8 years. The most frequent clinical subgroups were primary myositis (PM 29%, DM 22%), followed by overlap myositis (20.5%), juvenile myositis (18%), myositis associated with cancer (8%), immune-mediated necrotizing myositis (1%) and inclusion body myositis (1%). During the follow-up period, a total of 114 deaths (28%) were registered, the main causes being cancer (24%), infections (23%) and cardiovascular events (21%). CONCLUSIONS: A total of 479 patients were recruited in the REMICAM registry of inflammatory myopathies. Including sociodemographic, clinical and prognostic information, it represents the largest Spanish multicenter registry to date in rheumatology, and constitutes an important source for conducting further substudies.

Multicenter questionnaire survey for sporadic inclusion body myositis in Japan.

BACKGROUND: Sporadic inclusion body myositis (sIBM) is the most prevalent acquired muscle disease in the elderly. sIBM is an intractable and progressive disease of unknown cause and without effective treatment. The etiology of sIBM is still unknown; however, genetic factors, aging, lifestyles, and environmental factors may be involved. The purpose of this study is to elucidate the cross-sectional profile of patients affected by sIBM in Japan. METHODS: We surveyed patient data for 146 cases diagnosed at a number of centers across Japan. We also issued a questionnaire for 67 patients and direct caregivers to further elucidate the natural history of the disease. RESULTS: The mean age at the onset was 63.4 ± 9.2 years. The mean length of time from the onset to diagnosis was 55.52 ± 49.72 months, suggesting that there is a difficulty in diagnosing this disease with long-term consequences because of late treatment. 73 % described the psychological/mental aspect of the disease. The most popular primary caregiver was the patient's spouse and 57 % patients mentioned that they were having problems managing the finances. CONCLUSIONS: Through these surveys, we described the cross-sectional profiles of sIBM in Japan. Many patients described psychological/mental and financial anxiety because of the aged profile of sIBM patients. The profiles of sIBM patients are similar to those in Western countries.

Epidemiology of sporadic inclusion body myositis.

PURPOSE OF REVIEW: In this review, we describe recent progress in the clinical epidemiology of sporadic inclusion body myositis (IBM). RECENT FINDINGS: In a population-based, retrospective study from Norway, performed with a denominator population of 2.6 million; and with cases defined by the 1997 and/or 2011 European Neuro-Muscular Centre Research Diagnostic criteria, the estimated point prevalence of IBM was 3.3/100 000. Mean time from symptom onset to diagnosis was 5.6 years, longer than in earlier studies. The male to female ratio was 3 : 2, and the mean age at diagnosis 67 years, very similar to figures reported this year from a nationwide, Dutch myopathy registry. Coexisting rheumatic diseases were recorded in 25% of Norwegian IBM cases, with Sjøgren's syndrome as the most commonly encountered. Mortality was increased in IBM, with a standardized mortality rate of 1.7, but there was no indication of increased cancer risk. SUMMARY: Population-based data indicate that the prevalence of IBM in Europe is higher than expected from previous studies. Diagnostic delay appears to be a persisting problem in IBM; a major challenge with promising new therapies on the horizon.

Hepatitis C virus infection in inclusion body myositis: A case-control study.

OBJECTIVE: To clarify whether there is any association between inclusion body myositis (IBM) and hepatitis C virus (HCV) infection. METHODS: We assessed the prevalence of HCV infection in 114 patients with IBM whose muscle biopsies were analyzed pathologically for diagnostic purpose from 2002 to 2012 and in 44 age-matched patients with polymyositis diagnosed in the same period as a control by administering a questionnaire survey to the physicians in charge. We also compared clinicopathologic features including the duration from onset to development of representative symptoms of IBM and the extent of representative pathologic changes between patients with IBM with and without HCV infection. RESULTS: A significantly higher number of patients with IBM (28%) had anti-HCV antibodies as compared with patients with polymyositis (4.5%; odds ratio 8.2, 95% confidence interval 1.9-36) and the general Japanese population in their 60s (3.4%). Furthermore, between patients with IBM with and without HCV infection, we did not find any significant difference in the clinicopathologic features, indicating that the 2 groups have essentially the same disease regardless of HCV infection. CONCLUSION: Our results provide the statistical evidence for an association between IBM and HCV infection, suggesting a possible pathomechanistic link between the 2 conditions.

Clinicopathologic features of sporadic inclusion body myositis in China.

This study is to investigate the clinical and pathologic features of sporadic inclusion body myositis (sIBM) in China. We retrospectively evaluated the clinical and pathological features of consecutive patients in our department between January 1986 to May 2012. Total 28 cases of sIBM (20 males, 8 females, mean age was 56.93±8.79) were obtained by review of all 4099 muscle biopsy reports. The proportion of sIBM was 0.68% (28/4099) in China. Muscle weakness of quadriceps appeared 100% in 28 cases, while conspicuous atrophy of quadriceps appeared only in five cases (17.86%). Creatase values of 28 patients with sIBM were normal or mildly elevated. Muscle biopsies showed that atrophic fibers resembled more frequent in small angular and irregular shape (82.14%), less common in small round shape (17.86%). Rimmed vacuoles resembled crack (67.86%) and round (32.14%) shape. Mononuclear cell invasion into necrotic muscle fibers (35.71%) was more frequent than non-necrotic muscle fibers (7.14%). sIBM was still a rare disease in China compared to other countries. There were some certain specific pathological characteristics existed in Chinese sIBM patients.

[Inclusion body myositis]. / Zárványtestes myositis.

The idiopathic inflammatory myopathies are systemic, chronic autoimmune diseases characterized by proximal symmetrical muscle weakness. One of the main diseases in this group is inclusion body myositis (IBM), an underdiagnosed, progressive muscle disease characteristically affecting the middle-aged and older population. It has a slow, relentlessly progressive course. The precise pathogenesis of the disease remains unknown. In most of the cases it is diagnosed a few years after the appearance of the first symptoms. The muscle biopsy typically shows endomysial inflammation, with invasion of mononuclear cells into the non-necrotic fibers, and also rimmed vacuoles. It appers, that both inflammation and degeneration are present at the onset of the disease. Our aim is to raise awareness about this disease which leads to severe disability, with clinicopathological case presentations and literature overview, emphasizing the importance of collaboration between the clinician and the neuropathologist. No effective therapy is currently available but the rapid diagnosis is essential to slow disease progression. Although this is a relatively rare disease, patients are presenting not only in immunology outpatient clinics; our reports aims to raise awareness and facilitate accurate early diagnosis of IBM.