Prevalence Of Rheumatoid Arthritis Research Articles

Incidence and prevalence of rheumatoid arthritis in Denmark from 1998 to 2018: a nationwide register-based study

Objective To investigate the incidence and prevalence of rheumatoid arthritis (RA) in the adult Danish population. Method In this nationwide register-based cohort study, patients with incident RA between 1998 and the end of 2018 were identified using Danish administrative registries. The age- and sex-standardized incidence rate (IR), incidence proportion (IP), lifetime risk (LR), and point prevalence (PP) of RA were calculated. RA was defined as a first-time RA diagnosis registered in the Danish National Patient Registry combined with a redeemed prescription of a conventional synthetic disease-modifying anti-rheumatic drug in the following year. In addition, three different case definitions of RA were explored. Results The overall age- and sex-standardized IR of RA from 1998 to 2018 was 35.5 [95% confidence interval (CI) 35.1–35.9] per 100 000 person-years while the IP was 35.2 (95% CI 34.8–35.5) per 100 000 individuals. The IR was two-fold higher for women than for men. The LR of RA ranged from 2.3% to 3.4% for women and from 1.1% to 1.5% for men, depending on the RA case definition used. The overall PP of RA was 0.6% (95% CI 0.5–0.6%) in 2018: 0.8% (95% CI 0.7–0.8%) for women and 0.3% (95% CI 0.3–0.4%) for men. The prevalence increased about 1.5-fold from 2000 to 2018. Conclusion The IR and PP were approximately two-fold higher for women than for men. The prevalence of RA in Denmark increased significantly from 2000 to 2018. The RA case definition had more impact on the results than the choice of denominator.

Association between previous rheumatoid arthritis and COVID-19 and its severity: a nationwide cohort study in South Korea

ObjectivesThe prevalence of rheumatoid arthritis (RA) among patients with COVID-19 and the association between RA and the outcome of COVID-19 remain unclear. We aimed to compare the prevalence of RA...

Prevalence of rheumatoid arthritis in South America: a systematic review and meta-analysis.

Rheumatoid arthritis (RA) is among the most prevalent chronic autoimmune and inflammatory diseases worldwide. The aim of this study was to establish a pooled estimate of the RA prevalence in South America by means of a meta-analysis of the available epidemiologic studies. Systematic searches in PubMed, Lilacs, SciELO, Scopus, and Web of Science databases (updated May 2019) were done followed by a systematic grey literature search to identify original research articles and reports, published after 2000, providing data of RA prevalence in any South American country. Proportion meta-analysis of weighted pooled was performed, with between-trial heterogeneity assessed by the inconsistency relative index. Sensitivity analyses and sub-group analyses were also done. A total of 25 articles, representing 27 population-based studies were included. Pooled prevalence of RA resulted in 0.48% with 591,981 cases in a population of 114,537,812 individuals (I2=99%). Brazil and Colombia presented the lowest rates of RA prevalence 0.22%, and 0.24%, respectively. RA prevalence in indigenous population was higher 1.45%, and studies using COPCORD method reported also the highest rates 1.07%.

Can Studying Genetically Predisposed Individuals Inform Prevention Strategies for RA?

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder in which complex genetic predisposition interacts with multiple environmental factors to precipitate chronic and progressive immune-mediated joint inflammation. Currently, in most affected individuals, ongoing suppression of the inflammation is required to prevent irreversible damage and functional loss. The delineation of a protracted preclinical period in which autoimmunity is initially established and then evolves to become pathogenic provides unprecedented opportunities for interventions that have the potential to prevent the onset of this lifelong disease. Clinical trials aimed at assessing the impact of specific prevention strategies require the identification of individuals who are at high risk of future RA development. Currently, these risk factors include a strong family history of RA, and the detection of circulating RA-associated autoantibodies, particularly anti-citrullinated protein antibodies (ACPA). Yet, even in such individuals, there remains considerable uncertainty about the likelihood and the timeframe for future disease development. Thus, individuals who are approached to participate in such clinical trials are left weighing the risks and benefits of the prevention measures, while having large gaps in our current understanding. To address this challenge, we have undertaken longitudinal studies of the family members of Indigenous North American RA patients, this population being known to have a high prevalence of RA, early age of onset, and familial clustering of cases. Our studies have indicated that the concepts of “risk” and “prevention” need to be communicated in a culturally relevant manner, and proposed prevention interventions need to have an appropriate balance of effectiveness, safety, convenience, and cultural acceptability. We have focused our proposed prevention studies on immunomodulatory/anti-inflammatory nutritional supplements that appear to strike such a complex balance.

Methotrexate treatment before use of biologics in rheumatoid arthritis : Analysis of guideline compliance

With the introduction of biologics the treatment landscape for patients with rheumatoid arthritis (RA) has rapidly expanded; however, according to German and European treatment guidelines the use of biologic disease-modifying antirheumatic drugs (bDMARD) is only indicated after insufficient response under methotrexate (MTX) doses of at least 20 mg/week (first-line treatment). The aim of the study was to analyze the guideline compliance of MTX prescription in the outpatient sector prior to treatment with biologics. Claims data from the AOK Lower Saxony from 2013 to 2016 were provided for all insured patients with a diagnosis of RA and bDMARD prescription during the study period. Within apatient-specific observational period of 180days prior to the first bDMARD prescription, the maximum prescribed MTX dosage was examined. Data from 90incident and 315 prevalent RA patients were analyzed. Amaximum MTX prescription of < 20 mg/week was observed in 60.0% of incident patients and in 67.0% of prevalent patients. Men had ahigher mean MTX maximum dose (17.1 ± 4.8 mg) than women (14.9 ± 5.0 mg; p < 0.0001). Of the study population 29.6% received oral only prescriptions during the observational period. In 12.4% of patients aswitch to parenteral administration was made. Targeted use of the full spectrum of therapies provided prior to initiation of bDMARD treatment may contribute to cost-effective RA care. This study showed indications for potential deficits in outpatient MTX prescription practice and can raise awareness for efficient treatment.

749The global prevalence of Rheumatoid Arthritis: A meta-analysis

Abstract Background To determine the global prevalence of rheumatoid arthritis (RA) based on published studies and reveal factors which influence the RA prevalence estimates. Methods Four electronic databases- ProQuest Central, MEDLINE, Web of Science, and EMBASE were searched for publications from 1980 and 2019, reporting prevalence estimates of RA. A random-effect meta-analysis model was used to produce the pooled prevalence estimates. The potential sources of between-study heterogeneity were identified using sensitivity analysis, sub-group and meta-regression analyses. Results A total of 67 studies consisting of 212,335,171 patients were included in the meta-analysis. The global prevalence of RA was estimated 0.46% (95% CI: 0.39-0.54; I2=99.9%) with a 95% prediction interval (0.06–1.27). The point-prevalence of RA was 0.45% (95% CI: 0.38- 0.53%), while the pooled period-prevalence was 0.46% (0.36% and 0.57%). The highest RA pooled prevalence was estimated at 0.69% (95% CI: 0.47–0.95) derived from linked data sources studies. Based on subgroup analyses, the pooled prevalence of RA was influenced by geographical location, the risk bias of studies, period-prevalence method and urban population setting over the stratified periods. Conclusion The global prevalence of RA was 460 per 100,000 population from 1980–2018, with a 95% prediction interval (0.06– 1.27%). RA prevalence estimates were influenced by geographical location, the risk bias assessment of studies, period-prevalence method and urban population setting over time. Key messages The global prevalence of RA was 460 per 100,000 population from 1980–2018, with a 95% prediction interval (0.06– 1.27%).

Incidence, prevalence, and predictors of inflammatory arthritis in patients with hidradenitis suppurativa: a systematic review and meta-analysis.

An increasing amount of evidence has emerged suggesting that hidradenitis suppurativa (HS) is associated with inflammatory arthritis. This study reviewed the incidence, prevalence, and predictors of inflammatory arthritis in patients with HS. A comprehensive literature search was conducted in CINAHL, Embase, and Medline from inception to February 14, 2020. Articles were included in the review if they provided data on disease epidemiology or predictors of adult or pediatric HS patients with comorbid inflammatory arthritis. There are no validated diagnostic criteria for HS, thus we considered patients as having HS if they had at least one diagnostic code in a hospital or claims database or a diagnosis of HS/inflammatory arthritis in a medical record. The same criteria were used to confirm presence of inflammatory arthritis. We identified an increased incidence of rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) in HS patients when compared with estimates in the general population. We identified a relatively high prevalence of RA, spondyloarthritis (SpA), and PsA in HS patients when compared with estimates in the general population. There was evidence to suggest that patients who are younger than 30, male, have severe HS, or are taking infliximab or adalimumab (which may also be confounded by HS disease severity) may be at greater risk for specific subtypes of inflammatory arthritis. However, further data are needed to confirm these associations. The increased incidence and prevalence of inflammatory arthritis within HS patients underscore the need for increased awareness and interdisciplinary partnership within rheumatology and dermatology.

Epidemiological Trends of Rheumatoid Arthritis and PADI4, PTPN22, and HLA-DRB9 Genes Distribution in the Kazakhstan Population

BACKGROUND: The prevalence of rheumatoid arthritis (RA) is 1% in the global population. The lack of epidemiological studies in developing countries makes it difficult to obtain a complete global epidemiological picture of RA. RA develops due to the interaction of multiple genetic and environmental factors, though the contribution of these factors to the various disease occurrence seen in different populations is unclear. AIM: The aim of our study was to analyze the dynamics of the general prevalence and incidence of RA among the population of Kazakhstan in 2017–2019 as well as to investigate the three most common single-nucleotide polymorphisms (SNP) of RA in the Kazakhstan population. METHODS: The analysis of statistical data on Form 12 “On the health of the people and the health care system” was carried out. Prevalence and incidence rates were calculated according to generally accepted rules. Demographic data for the Republic of Kazakhstan were obtained from the official website stat.gov.kz. Our study included 70 RA patients and 113 control subjects. Blood samples were collected and genotyped for peptidylarginine deiminase 4 (PADI4), protein tyrosine phosphatase 22, and human leukocyte antigen (HLA)-DRB9 SNPs by reverse transcription polymerase chain reaction. RESULTS: The prevalence of RA in Kazakhstan in 2017–2019 was 0.36–0.38%, with an incidence rate of 0.085–0.087%, which can be comparable to data of other countries in Central Asia. The allele and genotypes frequency analyses were carried out between patients and controls. The HLA-DRB9 showed significant association of the G allele odds ratio (OR) 1.96 (95% confidence interval [CI]: 1.252–3.081), p= 0.0025 and G/G genotype OR = 3.67 (95% CI: 1.58–8.54), p = 0.00162 with RA in our sample. Strong association between anti-citrullinated protein antibody (ACPA) profile and PADI4 (OR 12.19 [95% CI: 2.19–67.94], p = 0.00115) was found. CONCLUSION: There was an increase in RA prevalence with age among females and a higher crude prevalence and incidence of RA in the southern regions of Kazakhstan. HLA-DRB9 prevailed in Kazakhstani patients with RA, PADI4 showed association with ACPA-positive RA. Further studies on larger samples are required to confirm our obtained results.

Hidradenitis suppurativa and rheumatoid arthritis: evaluating the bidirectional association

Despite some common pathogenic themes, the association of hidradenitis suppurativa (HS) and rheumatoid arthritis (RA) has been poorly investigated. We aimed to evaluate the bidirectional association between HS and RA. A population-based study was conducted to compare HS patients (n = 6779) with age-, sex- and ethnicity-matched control subjects (n = 33,260) with regard to the incidence of new-onset and the prevalence of preexisting RA. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were estimated. The prevalence of preexisting RA was greater among patients with HS relative to controls (0.5% vs 0.3%. respectively; p = 0.019). The odds of being diagnosed with HS were 1.6-fold higher in patients with a history of RA (fully-adjusted OR, 1.66; 95% CI, 1.11–2.49; p = 0.014). The incidence rate of new-onset RA was estimated at 4.3 (95% CI, 2.5–6.8) and 2.4 (95% CI, 1.8–3.2) cases per 10,000 person-years among patients with HS and controls, respectively. The risk of RA was comparable between patients with HS and controls (fully-adjusted HR, 1.45; 95% CI, 0.77–2.72; p = 0.249). Compared to other patients with HS, those with HS and comorbid RA were older, had a higher prevalence of diabetes mellitus, hypertension, and hyperlipidemia, and had a comparable risk of all-cause mortality. In conclusions, a preexisting diagnosis of RA predisposes individuals to develop HS. Clinicians managing patients with HS and RA should be aware of this association. Further research is required to delineate the underlying pathomechanism of this observation.

No association between rheumatoid arthritis and cognitive impairment in a cross-sectional national sample of older U.S. adults

BackgroundStudies suggest an increased prevalence of cognitive impairment (CI) among people with rheumatoid arthritis (RA). However, most prior studies have used convenience samples which are subject to selection biases or have failed to adjust for key confounding variables. We thus examined the association between CI and RA in a large national probability sample of older US adults.MethodsData were from interviews with 4462 participants in the 2016 wave of the nationally representative U.S. Health and Retirement Study with linked Medicare claims. RA diagnoses were identified via a minimum of two ICD-9CM or ICD-10 codes in Medicare billing records during the prior 2 years. The Langa-Weir Classification was used to classify cognitive status as normal, cognitively impaired non-dementia (CIND), or dementia based on a brief neuropsychological battery for self-respondents and informant reports for proxy respondents. We compared the odds of CI between older adults with and without RA using logistic regression, adjusted for age, education, gender, and race.ResultsMedicare records identified a 3.36% prevalence of RA (150/4462). While age, gender, education, and race independently predicted CI status, controlling for these covariates we found no difference in CI prevalence according to RA status (prevalent CI in 36.7% of older adults with RA vs. 34.0% without RA; adjusted OR = 1.08, 95% CI 0.74–1.59, p = .69).ConclusionThere was no association between RA and CI in this national sample of older U.S. adults.

Mycobacterium tuberculosis Immune Response in Patients With Immune-Mediated Inflammatory Disease.

Subjects with immune-mediated inflammatory diseases (IMID), such as rheumatoid arthritis (RA), have an intrinsic higher probability to develop active-tuberculosis (TB) compared to the general population. The risk ranges from 2.0 to 8.9 in RA patients not receiving therapies. According to the WHO, the RA prevalence varies between 0.3% and 1% and is more common in women and in developed countries. Therefore, the identification and treatment of TB infection (TBI) in this fragile population is important to propose the TB preventive therapy. We aimed to study the M. tuberculosis (Mtb) specific T-cell response to find immune biomarkers of Mtb burden or Mtb clearance in patients with different TB status and different risk to develop active-TB disease. We enrolled TBI subjects as example of Mtb-containment, the active-TB as example of a replicating Mtb status, and the TBI-IMID as fragile population. To study the Mtb-specific response in a condition of possible Mtb sterilization, we longitudinally enrolled TBI subjects and active-TB patients before and after TB therapy. Peripheral blood mononuclear cells were stimulated overnight with Mtb peptides contained in TB1- and TB2-tubes of the Quantiferon-Plus kit. Then, we characterized by cytometry the Mtb-specific CD4 and CD8 T cells. In TBI-IMID, the TB therapy did not affect the ability of CD4 T cells to produce interferon-γ, tumor necrosis factor-α, and interleukin-2, their functional status, and their phenotype. The TB therapy determined a contraction of the triple functional CD4 T cells of the TBI subjects and active-TB patients. The CD45RA- CD27+ T cells stood out as a main subset of the Mtb-specific response in all groups. Before the TB-preventive therapy, the TBI subjects had higher proportion of Mtb-specific CD45RA-CD27+CD4+ T cells and the active-TB subjects had higher proportion of Mtb-specific CD45RA-CD27-CD4+ T cells compared to other groups. The TBI-IMID patients showed a phenotype similar to TBI, suggesting that the type of IMID and the IMID therapy did not affect the activation status of Mtb-specific CD4 T cells. Future studies on a larger and better-stratified TBI-IMID population will help to understand the change of the Mtb-specific immune response over time and to identify possible immune biomarkers of Mtb-containment or active replication.

Prevalence Trend and Disparities in Rheumatoid Arthritis among US Adults, 2005–2018

Rheumatoid arthritis (RA) trends among US adults and disparities in RA patients in recent years have not been well described. We aimed to examine the trend of RA prevalence and disparities among US adults. Data from the National Health and Nutrition Examination Survey (NHANES) of the years 2005–2018 were analyzed to examine the self-reported RA prevalence trend. Age-adjusted RA prevalence stratified by race/ethnicity and socioeconomic status (SES), as well as associated linear trends, were calculated for both genders. The multivariable adjustment was used to evaluate the association between race, SES, and RA. During 2005–2018, there was no significant linear trend in the age-adjusted self-reported RA prevalence among men and women, but significant differences among people from different races, educational levels, and family poverty income ratio (PIR) groups were observed. The RA rate difference was significant for both genders and between Non-Hispanic Caucasians and Non-Hispanic African Americans (both p-value ≤ 0.001). Both men and women with a higher educational level and a higher PIR had a lower age-adjusted RA rate. Age-adjusted RA prevalence fluctuated for both men and women during 2005–2018. Non-Hispanic African Americans and people with low SES had significantly higher age-adjusted RA prevalence and RA risk.

Is Rheumatoid Arthritis Related to Coffee Consumption in Korea? A Nationwide Cross-Sectional Observational Study.

Coffee consumption is gradually increasing in Korea. As a result, interest in the relationship between coffee consumption and various diseases is growing. Several factors affect the development of rheumatoid arthritis (RA), and coffee consumption may be related. We conducted a nationwide cross-sectional study using data from the Korea National Health and Nutrition Examination Survey (2012–2016). A total of 12,465 eligible participants (4819 men and 7646 women) were included in the study. Participants with RA were defined as those who were diagnosed and currently being treated by physicians. Daily coffee consumption amounts were categorized as none, <1 cup, 1–2 cups, 2–3 cups, and ≥3 cups a day based on a self-report. A multivariable logistic regression model was employed, and we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for the odds of participants having RA with respect to coffee consumption. Compared to the no-coffee group, the ORs for RA in the <1 cup and 1–2 cups groups were 2.99 (95% CI 0.33–27.28) and 2.63 (95% CI 0.31–22.63) in men, respectively, and the ORs for RA for women in the <1 cup, 1–2 cups, 2–3 cups, and ≥3 cups groups were 0.62 (95% CI 0.31–1.26), 0.67 (95% CI 0.33–1.37), 1.08 (95% CI 0.35–3.36), and 1.43 (95% CI 0.25–8.36), respectively. Our study concludes, therefore, that daily coffee consumption is not related to the prevalence of RA in the general Korean population.

Polycystic ovary syndrome: epidemiologic assessment of prevalence of systemic rheumatic and autoimmune diseases.

Polycystic ovary syndrome (PCOS) causes anovulation and hyperandrogenism. Hormonal imbalance is known to contribute to systemic autoimmune diseases. To examine the frequency of certain rheumatic diseases in PCOS. This retrospective study utilized and analyzed electronic medical records from January 2004 through February 2020. A diagnosis of PCOS and specified rheumatic diseases was searched using ICD-9 and ICD-10 codes. A total of 754 adult patients with PCOS and 1,508 age- and body mass index-matched patients without PCOS were included. Frequencies of the rheumatic diseases were compared between PCOS and non-PCOS subjects or literature data. The prevalence of rheumatoid arthritis (RA) was found to be 2.25% (17/737) in the PCOS patients, numerically higher than 1.26% (19/1489) in the non-PCOS subjects. The difference was significant with a confidence level of 90% (1.04-3.15) but not at 95% with an odds ratio of 1.808 (95% CI = 0.934-3.4, p = 0.0747). When compared with the literature data from the US female population, the prevalence of RA in PCOS patients was significantly higher (2.25% vs. 1.40%, p < 0.0001). Among the autoimmune diseases examined, both systemic sclerosis (0.40% vs. 0.0%, p = 0.0369) and undifferentiated connective tissue disease (0.53% vs. 0.0%, p = 0.0123) were significantly more frequent in the PCOS patients than the non-PCOS. Additionally, PCOS patients had a significantly higher frequency of osteoarthritis than non-PCOS patients (5.44% vs. 2.92%, p = 0.0030) with an odds ratio of 1.913 (95% CI = 1.239-2.955). We have shown unprecedentedly that certain rheumatic diseases are more prevalent in PCOS. This study provides important insight into autoimmunity in association with PCOS. Key Points • Polycystic ovary syndrome is postulated to cause systemic autoimmune disease due to its hormonal imbalance. • We conducted the first epidemiologic assessment of the prevalence of systemic autoimmune diseases. • Certain autoimmune and rheumatic diseases are more prevalent in polycystic ovary syndrome.

Association of human T-cell leukemia virus type 1 with prevalent rheumatoid arthritis among atomic bomb survivors: A cross-sectional study.

Previous studies have suggested that human T-cell leukemia virus type 1 (HTLV-1) might act as a pathogen in rheumatoid arthritis (RA), but epidemiological evidence of an association is scarce. We measured anti-HTLV-1 antibodies among Nagasaki atomic bomb survivors to determine whether HTLV-1 is related to RA and whether radiation exposure is associated with HTLV-1 and RA prevalence.This is a cross-sectional study among atomic bomb survivors who participated in biennial health examinations from 2006 to 2010. Serum levels of anti-HTLV-1 antibodies were measured using a chemiluminescent enzyme immunoassay and confirmed by Western blotting. Association between HTLV-1 and RA was analyzed by a logistic regression model.Of 2091 participants (women 61.5%; median age, 73 years), 215 (10.3%) had anti-HTLV-1 antibodies. HTLV-1 prevalence was higher among women (13.1% vs 5.8%; P < .001). Twenty-two participants (1.1%) were diagnosed with RA. HTLV-1 prevalence among RA participants was significantly higher than that among non-RA participants (27.3% vs 10.1%; P = .020). After adjustment for age, sex, and hepatitis C virus infection, HTLV-1 was significantly associated with prevalent RA (odds ratio, 2.89; 95% confidence interval, 1.06, 7.03). There was no association between radiation dose and either the prevalence of HTLV-1 or RA.This study, among a well-defined group of atomic bomb survivors, suggests that HTLV-1 is associated with RA.

Porphyromonas gingivalis induces periodontitis, causes immune imbalance, and promotes rheumatoid arthritis.

Periodontitis induced by bacteria especially Porphyromonas gingivalis (P. gingivalis) is the most prevalent microbial disease worldwide and is a significant risk factor for systemic diseases such as rheumatoid arthritis (RA). RA and periodontitis share similar clinical and pathologic features. Moreover, the prevalence of RA is much higher in patients with periodontitis than in those without periodontitis. To explore the immunologic mechanism of periodontitis involved in RA, we established a mouse model of periodontitis and then induced RA. According to the results of paw thickness, arthritis clinical score, arthritis incidence, microscopic lesion using H&E staining, and micro-CT analysis, periodontitis induced by P. gingivalis promoted the occurrence and development of collagen-induced arthritis (CIA) in mice. Furthermore, periodontitis enhanced the frequency of CD19+ B cells, Th17, Treg, gMDSCs, and mMDSCs, whereas down-regulated IL-10 producing regulatory B cells (B10) in CIA mice preinduced for periodontitis with P. gingivalis. In vitro stimulation with splenic cells revealed that P. gingivalis directly enhanced differentiation of Th17, Treg, and mMDSCs but inhibited the process of B cell differentiation into B10 cells. Considering that adoptive transfer of B10 cells prevent RA development, our study, although preliminary, suggests that down-regulation of B10 cells may be the key mechanism that periodontitis promotes RA as the other main immune suppressive cells such as Treg and MDSCs are up-regulated other than down-regulated in group of P. gingivalis plus CIA.

Prevalence of chronic obstructive pulmonary disease in patients with rheumatoid arthritis: A cross-sectional study.

Rheumatoid arthritis (RA) and chronic obstructive pulmonary disease (COPD) are both chronic inflammatory diseases; the prevalence of COPD in RA patients is known to be high. However, the prevalence of both RA and COPD differs according to sex; the relationship between RA and COPD may also vary according to sex. Therefore, we investigated the prevalence of COPD and its association in patients with RA in Korea by sex. We conducted a nationwide cross-sectional study using data from the Korea National Health and Nutrition Examination Survey. A total of 12417 men and 15878 women were included. In this study, RA was defined as physician diagnosed or currently under RA treatment. COPD was defined based on spirometry results, chronic symptoms, and smoking history. Multivariable logistic regression models were employed and we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for COPD prevalence in patients with RA. The prevalence of COPD was 15.5% in men with RA, 3.5% in women with RA, 7.8% in men without RA, and 2.2% in women without RA. After adjustment for potential confounding variables, including smoking status, RA was significantly associated with COPD in men (OR 2.16, 95% CI 1.06-4.40), but not in women (OR 1.58, 95% CI 0.81-3.10). In Korea, the prevalence of COPD was high in patients with RA of both sexes; RA and COPD was significantly likely to be associated in men, but not in women.

POS0029 INCIDENCE AND TREATMENT PENETRATION OF RHEUMATOID ARTHRITIS IN NORWAY – A NATIONWIDE REGISTER LINKAGE STUDY

Background:Incidence of rheumatoid arthritis (RA) in Norway has not been evaluated in a nationwide setting.Objectives:To estimate the incidence of RA and real-life penetration of disease-modifying antirheumatic drug (DMARD) use in Norway.Methods:The Norwegian Cardio-Rheuma register comprises pseudonymized data from nationwide registries including the total Norwegian population ≥18 years during 2008-2017. Demographic and socioeconomic data were retrieved from the National Population Register and Statistics Norway. Data on public or private somatic specialized care episodes were collected from the Norwegian Patient register (NPR) (ICD-10 codes for diagnoses and medical procedure codes for biologic DMARD infusions). Dispensed DMARD prescriptions were captured from the Norwegian Prescription Database. RA cases were defined as persons with NPR records of all of the following: 1) 1st episode with ICD-10 code M05/M06 as main or contributory diagnosis (index date), 2) 2nd episode with code M05/M06 within 2-year period following index date, 3) M05/M06 recorded in an internal medicine or rheumatology department during the 2-year period. Years 2008-2010 served as a look-back period to identify prevalent RA cases. To estimate person-years (pyrs) at risk, we calculated number of persons aged ≥ 18 living in Norway on the 1st of January of each year 2011-2015 and multiplied it by one year (prevalent RA cases excluded). Standardized estimates were calculated with 5-year age groups using Norwegian adult population 1st of January 2015 as the standard.Results:Between 2011 and 2015, 9,493 persons fulfilled the RA definition (62.4% seropositive based on ICD-10 codes). Incidence rate was 49/100,000 pyrs (32 in men and 65 in women). A sensitivity analysis excluding cases who had dispensed DMARDs &gt;12 months before index date yielded 8,125 RA cases (incidence 42/100,000 pyrs). Whereas absolute number of incident cases was highest among those aged 60-69 in both sexes, incidence was highest among those aged 70-79 (Figure 1). Both crude and age- and sex-standardized incidences were lower among persons with higher education level (crude/standardized incidence per 100,000 pyrs for those below upper secondary education 60/57; upper secondary or post-secondary non-tertiary education 53/52; higher education 36/39). Of incident cases, 94% received any DMARD treatment or glucocorticoids, 78% methotrexate, and 17% biologic DMARDs within 2 years after index date (Table 1).Conclusion:Contemporary register-based estimate of RA incidence in Norway is comparable to other Nordic countries.1,2 In line with treatment recommendations, methotrexate is the most commonly used DMARD in the initial treatment strategy in Norway. One in six patients used a biologic DMARD within 2 years from 1st recorded RA diagnosis.

A Population-Based Approach to Reporting System-Level Performance Measures for Rheumatoid Arthritis Care.

To operationalize and report on nationally endorsed rheumatoid arthritis (RA) performance measures (PMs) using health administrative data for British Columbia (BC), Canada. All patients with RA in BC ages ≥18 years were identified between January 1, 1997 and December 31, 2009 using health administrative data and followed until December 2014. PMs tested include: the percentage of incident patients with ≥1 rheumatologist visit within 365 days; the percentage of prevalent patients with ≥1 rheumatologist visit per year; the percentage of prevalent patients dispensed disease-modifying antirheumatic drug (DMARD) therapy; and time from RA diagnosis to DMARD therapy. Measures were reported on patients seen by rheumatologists, and in the total population. The cohort included 38,673 incident and 57,922 prevalent RA cases. The percentage of patients seen by a rheumatologist within 365 days increased over time (35% in 2000 to 65% in 2009), while the percentage of RA patients under the care of a rheumatologist seen yearly declined (79% in 2001 to 39% in 2014). The decline was due to decreasing visit rates with increasing follow-up time rather than calendar effect. The percentage of RA patients dispensed a DMARD was suboptimal over follow-up (37% in 2014) in the total population but higher (87%) in those under current rheumatologist care. The median time to DMARD in those seen by a rheumatologist improved from 49 days in 2000 to 23 days in 2009, with 34% receiving treatment within the 14-day benchmark. This study describes the operationalization and reporting of national PMs using administrative data and identifies gaps in care to further examine and address.

The validity of the claims-based definition of rheumatoid arthritis evaluated in 64 hospitals in Japan

BackgroundAn administrative database covering a whole population such as the national database in Japan may be used to estimate the nationwide prevalence of diseases including rheumatoid arthritis (RA) when a well-validated definition of the disease is available. In Japan, the record linkage between the administrative database and medical charts in hospitals is strictly prohibited. A “hospital-based” validation study is one of few possible validation studies where claims kept inside the study hospital are rearranged into the database structure.MethodsWe selected random samples of 19,734 patients from approximately 1.6 million patients who received medical care between February 2018 and January 2019 in one of the 64 hospitals of the Tokushukai Medical Group. We excluded patients whose observation period was less than 365 days and identified 334 patients who met the definition of “possible cases of RA” whose medical charts were then independently evaluated by two rheumatologists. In a sensitivity analysis, we assessed bias due to misclassifying some patients with RA who did not meet the definition of “possible cases of RA” as a patient with no RA.ResultsThe kappa coefficient between the two rheumatologists was 0.80. The prevalence of RA in the study population was estimated to be 0.56%. We found that [condition code of RA] and ([any disease-modifying antirheumatic drug] or [oral corticosteroid with no systemic autoimmune diseases (other than RA) and no polymyalgia rheumatica]) had a relatively high sensitivity (approximately 73%) and a high positive predictive value (approximately 80%). In a sensitivity analysis, we found that when some patients with RA who did not meet the definition of “possible cases of RA” were misclassified as a patient with no RA, then this would lead to underestimation of the prevalence of the definition-positive patients and the adjusted prevalence.ConclusionsWe recommend using the claims-based definition of RA (found in the current validation study) to estimate the prevalence of RA in Japan. We also suggest estimating the adjusted prevalence using the quantitative bias analysis method, since the prevalence of the disease in the “hospital-based” validation study is different from that in the administrative database.Trial registrationThe current study is not a clinical trial and hence not subject to trial registration.