Prevalence of patients with rheumatoid arthritis and age-stratified trends in clinical characteristics and treatment, based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan

Methotrexate, Tofacitinib, and Biologic Disease-Modifying Antirheumatic Drug Safety and Effectiveness Among Patients with Rheumatoid Arthritis in Japan: CorEvitas Registry Observational Study

INTRODUCTION

The evolution of disease-modifying antirheumatic drugs (DMARDs) for the treatment of rheumatoid arthritis (RA) has improved patient prognosis. However, more real-world safety/effectiveness data comparing methotrexate (MTX), tofacitinib, tumor necrosis factor inhibitors (TNFi), and non-TNFi biologic DMARDs (bDMARDs) are warranted.

METHODS

The CorEvitas RA Japan registry was used to identify patients with rheumatologist-diagnosed RA who initiated MTX/tofacitinib/TNFi/non-TNFi bDMARDs. Safety outcomes included incidence of major adverse cardiovascular events (MACE), total cardiovascular disease, total serious infections, total herpes zoster, and total malignancies (excluding non-melanoma skin cancer). Effectiveness outcomes included change from baseline (Δ) in Clinical Disease Activity Index (CDAI) and proportion of patients achieving a minimum clinically important difference (MCID) in CDAI at month 6. Adjusted regression models were fit; marginal means were estimated.

RESULTS

Overall, 1972 patients were included in the safety cohort: MTX (N = 298); tofacitinib (N = 253); TNFi (N = 663); non-TNFi (N = 758). Mean follow-up time was 3.8, 2.9, 3.0, and 2.9 years for MTX, tofacitinib, TNFi, and non-TNFi, respectively. Adjusted incidence rates (IRs, patients with events/100 patient-years [95% confidence intervals]) for MACE and total cardiovascular disease, respectively, were numerically lower for MTX (0.34 [0, 0.83]; 0.42 [0, 0.92]) and TNFi (0.09 [0, 0.27]; 0.61 [0.15, 1.07]) versus tofacitinib (0.48 [0, 1.20]; 2.30 [0.38, 4.22]) and non-TNFi (0.77 [0.35, 1.19]; 1.28 [0.73, 1.82]). Serious infections were numerically higher for non-TNFi (4.47 [3.38, 5.56]); herpes zoster was higher for tofacitinib (7.41 [4.52, 10.29]), versus other groups. IRs for malignancies were comparable between groups. Mean ΔCDAI and rates of achieving MCID in CDAI at month 6 were generally greater with tofacitinib versus other groups.

CONCLUSION

Some variations in incidence of safety outcomes were observed between treatments, while certain effectiveness outcomes favored tofacitinib. Sample size variation between groups and low number of safety events limited the analysis. Further studies are warranted to investigate observed differences.

CLINICALTRIALS

GOV: NCT05572567.

The Association Between Deep Vein Thrombosis, Pulmonary Embolism, and Janus Kinase Inhibitors: Reporting Status and Signal Detection in the Japanese Adverse Drug Event Report Database

BACKGROUND

Although Janus kinase (JAK) inhibitors have expanding indications, deep vein thrombosis (DVT) and pulmonary embolism (PE) are serious adverse events associated with their use. Moreover, their analysis using the Japanese database of spontaneous adverse drug reaction reports has not yet been conducted.

OBJECTIVE

The objective of this study was to analyze the Japanese Adverse Drug Event Report database (JADER) to evaluate the association between JAK inhibitors and DVT and PE.

METHODS

JADER reports from April 2004 to October 2023 were analyzed. A classification of reports for the period covered was performed by drug, and an imbalance analysis was performed with oral JAK inhibitors as the target drug and DVT, PE, and "embolic and thrombotic events, venous" (Standardised MedDRA Query; SMQ) as the target adverse events. Reported odds ratios (ROR) and information components (IC) were calculated for signal detection.

RESULTS

Overall, 6631 JAK inhibitor-related adverse events were reported, including 60 and 41 cases of DVT and PE, respectively. The ROR and IC of the JAK inhibitors for DVT were 2.52 (1.95-3.25) and 1.27 (0.41-2.13), while those of baricitinib for DVT were 4.37 (2.83-6.73) and 1.90 (0.47-3.33), respectively. ROR signals were detected for JAK inhibitors for PE and "embolic and thrombotic events, venous (SMQ)," overall and for several JAK inhibitors but none for IC.

CONCLUSIONS

Several JAK inhibitors are under postmarketing phase vigilance, and the number of reported adverse events is low. However, when administering these drugs, care should be taken to avoid the development of thromboembolism, considering the patient's background.

Inflammatory diseases causing joint and bone destruction: rheumatoid arthritis and hemophilic arthropathy

Various diseases and conditions cause joint disorders. Osteoarthritis (OA) is characterized by the degeneration of articular cartilage, synovitis, and anabolic changes in surrounding bone tissues. In contrast, rheumatoid arthritis (RA) and hemophilic arthropathy (HA) display marked destruction of bone tissues caused by synovitis. RA is a representative autoimmune disease. The primary tissue of RA pathogenesis is the synovial membrane and involves various immune cells that produce catabolic cytokines and enzymes. Hemophilia is a genetic disorder caused by a deficiency in blood clotting factors. Recurrent intra-articular bleeding leads to chronic synovitis through excessive iron deposition and results in the destruction of affected joints. Although the triggers for these two joint diseases are completely different, many cytokines and enzymes are common in the pathogenesis of both RA and HA. This review focuses on the similarities between joint and bone destruction in RA and HA. The insights may be useful in developing better treatments for hemophilia patients with arthropathy and osteoporosis by leveraging advanced therapeutics for RA.

Treatment Patterns of Biologic Disease-Modifying Antirheumatic Drugs and Janus Kinase Inhibitors in Patients with Rheumatoid Arthritis in Japan: A Claims-Based Cohort Study

BACKGROUND

Reports on treatment patterns of biologic disease-modifying antirheumatic drugs (bDMARDs)/Janus kinase inhibitors (JAKi) for rheumatoid arthritis (RA) in clinical practice are still sparse in Japan, especially in combination with conventional synthetic DMARDs (csDMARDs).

OBJECTIVES

The aim of this study was to investigate treatment patterns of bDMARD/JAKi in the treatment of RA in real-world clinical practice in Japan.

METHOD

A retrospective cohort study was conducted using the Japanese Medical Data Vision health claims database. The inclusion criteria required a recorded diagnosis of RA, defined by ICD-10 codes, in patients aged 18 years and older on the index date. We analyzed 39,903 RA patients treated with DMARDs from 2008 to 2020.

RESULTS

Among analyzed subjects, 10,196 patients (25.6%) were prescribed bDMARDs/JAKi in combination with csDMARDs, and 3067 patients (7.7%) were prescribed these drugs without csDMARDs. Among the bDMARDs/JAKi, tumor necrosis factor inhibitors (TNFi) were the most commonly prescribed DMARD overall, and also the most common first-line therapy, accounting for 60.0% or 45.5% of patients prescribed these drugs in combination with or without csDMARDs, respectively. Switching, temporary discontinuation (restarting with the same agents), and discontinuation of bDMARDs/JAKi were observed in 3150 (30.9%), 1379 (13.5%), and 2025 (19.9%) patients with csDMARDs, and in 849 (27.7%), 513 (16.7%), and 833 (27.2%) patients without csDMARDs, respectively.

CONCLUSIONS

Real-world treatment trajectories of bDMARDs/JAKi with and without csDMARDs was analyzed in RA patients in Japan between 2008 and 2020. TNFi were the predominant first-line therapy, and likely to be switched to different classes. Understanding the current treatment patterns, including discontinuation, is important to find an optimal treatment strategy for RA patients.

Individual and population-level variability in HLA-DR associated immunogenicity risk of biologics used for the treatment of rheumatoid arthritis

Hypothesis

While conventional in silico immunogenicity risk assessments focus on measuring immunogenicity based on the potential of therapeutic proteins to be processed and presented by a global population-wide set of human leukocyte antigen (HLA) alleles to T cells, future refinements might adjust for HLA allele frequencies in different geographic regions or populations, as well for as individuals in those populations. Adjustment by HLA allele distribution may reveal risk patterns that are specific to population groups or individuals, which current methods that rely on global-population HLA prevalence may obscure.

Key findings

This analysis uses HLA frequency-weighted binding predictions to define immunogenicity risk for global and sub-global populations. A comparison of assessments tuned for North American/European versus Japanese/Asian populations suggests that the potential for anti-therapeutic responses (anti-therapeutic antibodies or ATA) for several commonly prescribed Rheumatoid Arthritis (RA) therapeutic biologics may differ, significantly, between the Caucasian and Japanese populations. This appears to align with reports of differing product-related immunogenicity that is observed in different populations.

Relevance to clinical practice

Further definition of population-level (regional) and individual patient-specific immunogenic risk profiles may enable prescription of the RA therapeutic with the highest probability of success to each patient, depending on their population of origin and/or their individual HLA background. Furthermore, HLA-specific immunogenicity outcomes data are limited, thus there is a need to expand HLA-association studies that examine the relationship between HLA haplotype and ATA in the clinic.

Impact of interstitial lung disease on clinical remission and unfavourable events of rheumatoid arthritis: results from the IORRA cohort

OBJECTIVES

We aimed to examine the impact of concomitant interstitial lung disease (ILD) on achieving clinical remission and the occurrence of unfavourable clinical events in patients with RA.

METHODS

Among the participants in the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort from 2011 to 2012, patients not achieving remission of 28-joint disease activity score (DAS28) at baseline and those with chest CT images were enrolled. Based on the chest CT images, the patients were divided into two groups: the ILD group and non-ILD group. The associations among the presence of ILD with time to achieving DAS28 remission and development of death, hospitalized infection, major adverse cardiac events (MACE), or malignancy within 5 years were evaluated using time-dependent Cox regression models.

RESULTS

We enrolled 287 patients in the ILD group and 1235 in the non-ILD group. DAS28 remission was achieved at least once in 55.7% and 75.0% of the ILD and non-ILD groups within 5 years, respectively. Presence of ILD was significantly associated with failure to achieve DAS28 remission (adjusted hazard ratio [aHR]: 0.71; 95% CI: 0.58, 0.89). ILD was also a significant factor associated with death (aHR: 3.24; 95% CI: 2.08, 5.03), hospitalized infection (aHR 2.60; 95% CI: 1.77, 3.83), MACE (aHR: 3.40; 95% CI: 1.76, 6.58), and lung cancer (aHR: 16.0; 95% CI: 3.22, 79.2), but not with malignant lymphoma (aHR: 2.27; 95% CI: 0.59, 8.81).

CONCLUSION

Concomitant ILD was a significant factor associated with failure to achieve clinical remission and the occurrence of the unfavourable clinical events in patients with RA.

Annual numbers of diagnoses and medical expenses for obstetric diseases in Japan: A report from the National Database of Health Insurance Claims

AIM

The present study aimed to estimate the total numbers of obstetric diseases diagnosed, total amounts of medical expenses claimed for obstetric diseases, their averages per livebirth, and yearly trends in Japan.

METHODS

This is a secondary analysis of the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) (data from 2015 to 2019). The target population was women of reproductive age (15-49 years old) with diseases in pregnancy, childbirth, and the puerperium, defined by having O codes according to the International Classification of Diseases 10th Revision. We calculated the numbers of obstetric diseases diagnosed, amounts of medical expenses claimed for obstetric diseases marked with the "main injury/disease decision flag," and the totals divided by the annual numbers of livebirths, by year and women's age group.

RESULTS

From 2015 to 2019, both the numbers of obstetric diseases diagnosed and amounts of medical expenses claimed for obstetric diseases per livebirth were on an upward trend, whereas the total numbers of obstetric diseases diagnosed were decreased. Women in advanced age groups had a higher number of diagnoses and a higher amount of medical expenses for obstetric diseases per livebirth. "Preterm labour without delivery" had the highest amounts of medical expenses claimed for and the second highest numbers of diagnoses throughout the study period.

CONCLUSIONS

This study suggests that pregnant women in Japan would have an increasing number of obstetric complications and necessary medical expenses year by year. Further study is warranted to elucidate these trends and identify possible mitigation measures.

Development of a nursing practice scale for rheumatoid arthritis treatment with biological disease-modifying anti-rheumatic drugs

OBJECTIVE

The objective of the study was to develop a nursing practice scale for rheumatoid arthritis treatment with biological disease-modifying anti-rheumatic drugs.

METHODS

An anonymous self-administered questionnaire survey was administered to 1826 nurses, 960 of whom were Certified Nurses by Japan Rheumatism Foundation (CNJRFs) and 866 were registered nurses (RNs). Using exploratory factor analysis, criterion validity, and known-groups technique, we assessed the reliability and validity of the self-created 19-item nursing practice scale to evaluate the care provided to patients with rheumatoid arthritis receiving biological disease-modifying anti-rheumatic drugs based on the nurse's role as clarified from a literature review of relevant studies.

RESULTS

A total of 698 (38.4%) responses were collected from 407 CNJRFs and 291 RNs. Exploratory factor analysis was conducted on 18 items to examine three factors: 'nursing to enhance patients' capacity for self-care', 'nursing in which patients participate in decision-making', and 'nursing in which team medical care is promoted'. Cronbach's α was .95. The Spearman's coefficient was ρ = .738 for criterion validity. Using the known-groups technique, CNJRFs had higher total scale scores than RNs (P < .05).

CONCLUSIONS

The results confirmed the reliability, criterion validity, and construct validity of the scale.

Comparison of effectiveness of methotrexate in patients with late-onset versus younger-onset rheumatoid arthritis: Real-world data from an inception cohort in Japan (NICER-J)

OBJECTIVE

To compare the effectiveness of methotrexate (MTX) as initial therapy in patients with late-onset and younger-onset rheumatoid arthritis (LORA and YORA).

METHODS

Of 114 patients with YORA and 96 patients with LORA, defined as RA occurring at ≥65 years of age, enrolled in a multicentre RA inception cohort study, 71 and 66 patients who had been followed up to 6 months after starting MTX treatment were included in this study.

RESULTS

Proportions of patients on MTX treatment at 6 months were 96% and 92% in the YORA and LORA groups, respectively. Despite lower doses of MTX in the LORA group compared with the YORA group, no significant difference was observed in clinical disease activity index scores between the two groups throughout the follow-up period. The proportion of patients in clinical disease activity index remission at 6 months was 35% in both groups. Logistic regression analysis revealed that knee joint involvement and high Health Assessment Questionnaire-Disability Index were significant negative predictors of achieving clinical disease activity index remission at 6 months in the LORA group.

CONCLUSION

Observations up to 6 months revealed that the effectiveness of MTX administered based on rheumatologist discretion in patients with LORA is comparable to that in patients with YORA in clinical settings.

Consensus statement on the management of late-onset rheumatoid arthritis

OBJECTIVES

Late-onset rheumatoid arthritis (LORA), which has been increasing in recent years, lacks evidence for initial treatment. Japanese rheumatology experts recognized this gap and addressed it by developing consensus statements on the first clinical application of LORA.

METHODS

These statements were created following an introductory discussion about treatment fundamentals, which included a review of existing literature and cohort data. The steering committee created a draft, which was refined using a modified Delphi method that involved panel members reaching a consensus. The panel made decisions based on input from geriatric experts, clinical epidemiologists, guideline developers, patient groups, and the LORA Research Subcommittee of the Japan College of Rheumatology.

RESULTS

The consensus identified four established facts, three basic approaches, and six expert opinions for managing LORA. Methotrexate was recommended as the primary treatment, with molecular-targeted agents being considered if treatment goals cannot be achieved. An emphasis was placed on assessing the lives of older patients due to challenges in risk management and methotrexate accessibility caused by comorbidities or cognitive decline.

CONCLUSIONS

The experts substantiated and refined 13 statements for the initial treatment of LORA. To validate these claims, the next is to conduct a registry study focusing on new LORA cases.

Risk of hospitalized infections in older elderly patients with rheumatoid arthritis treated with tocilizumab or other biological/targeted synthetic disease-modifying antirheumatic drugs: Evaluation of data from a Japanese claims database

OBJECTIVE

We compared the incidence rates of hospitalized infections (HIs) between tocilizumab (TCZ) and other biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in adults aged ≥75 years with rheumatoid arthritis (RA).

METHODS

We used a Japanese claims database from Medical Data Vision Co., Ltd (Tokyo, Japan) to perform a retrospective longitudinal population-based study in patients with RA who were prescribed b/tsDMARDs between 2014 and 2019. We calculated adjusted risk ratios (aRRs) for HIs in three age groups (<65, ≥65 and <75, and ≥75 years).

RESULTS

Of 5506 patients, 2265 (41.1%) were <65 years, 1709 (31.0%) were 65-74 years, and 1532 (27.8%) were ≥75 years. Crude incidence rates (/100 person-years) of HIs were 3.99, 7.27, and 10.77, respectively. In the oldest group, aRRs (95% confidence interval) for HIs (b/tsDMARDs versus TCZ) were as follows: etanercept, 2.40 (1.24-4.61); adalimumab, 1.90 (0.75-4.83); golimumab, 1.21 (0.66-2.23); and abatacept, 0.89 (0.49-1.62). In the other age groups, the noticeable difference was a lower aRR of etanercept versus TCZ in the youngest group (0.30, 0.11-0.85).

CONCLUSION

In patients with RA aged ≥75 years, b/tsDMARDs have a similar risk of HIs to tocilizumab except for etanercept.

Effectiveness and safety of treat-to-target strategy for methotrexate-naïve rheumatoid arthritis patients >75 years of age

Objectives

To identify differences in effectiveness and safety of a treat-to-target (T2T) strategy comparing late-onset MTX-naïve RA patients (LORA) ≥75 or <75 years of age.

Methods

Treatment was adjusted to target low disease activity with conventional synthetic DMARDs followed by biologic DMARDs (bDMARDs) in LORA ≥75 years (n = 98, mean age 80.0 years) and LORA <75 years (n = 99) with moderate-high disease activity. Achievement of Simplified Disease Activity Index (SDAI) remission at week 156 by non-responder imputation analysis was evaluated as a primary outcome.

Results

LORA ≥75 years had more comorbidities than LORA <75 years, but SDAI and ACPA positivity were similar at baseline. Of the LORA ≥75 years, 70.4% started MTX and 34.1% and 37.1% received a bDMARD at week 52 and 156, respectively (very similar to the LORA <75 years). Glucocorticoid use was more frequent in the LORA ≥75 years than in the LORA <75 years. Comorbidities/adverse events more frequently contributed to the reasons for non-adherence to T2T in the LORA ≥75 than in the LORA <75. At week 156, 32.7% of the LORA ≥75 and 66.7% of the LORA <75 achieved SDAI remission (P < 0.001). The cumulative incidence of serious adverse events (SAEs) over 156 weeks was 42.8% in the LORA ≥75 and 22.1% in the LORA <75. Multivariable analysis indicated an increased risk of SDAI non-remission at week 156 in the LORA ≥75 [odds ratio 2.82 (95% CI 1.29. 6.14)] after adjusting for comorbidities at baseline, non-adherence to T2T and SAEs.

Conclusions

It was more difficult to achieve remission in the LORA ≥75 patients than in the LORA <75 patients due to both poor treatment response and safety issues.

Validation of claims-based algorithms for rheumatoid arthritis in Japan: Results from the VALIDATE-J study

AIM

Validity of Algorithms in Large Databases: Infectious Diseases, Rheumatoid Arthritis, and Tumor Evaluation in Japan (VALIDATE-J) study examined algorithms for identifying rheumatoid arthritis (RA) in Japanese claims data.

METHODS

VALIDATE-J was a multicenter, cross-sectional retrospective study. Disease-identifying algorithms were used to detect RA diagnosed between January 2012 and December 2016 using claims data from two Japanese hospitals. An RA diagnosis was confirmed using one of four gold standard definitions. Positive predictive values (PPVs) were calculated for prevalent (regardless of baseline RA-free period) and incident (preceded by a 12-month RA-free period) cases.

RESULTS

Of patients identified using claims-based algorithms, a random sample of 389 prevalent and 134 incident cases of RA were included. Cases identified by an RA diagnosis, no diagnosis of psoriasis, and treatment with any disease-modifying antirheumatic drugs (DMARDs) resulted in the highest PPVs versus other claims-based treatment categories (29.0%-88.3% [prevalent] and 41.0%-78.2% [incident]); cases identified by an RA diagnosis, no diagnosis of psoriasis, and glucocorticoid-only treatment had the lowest PPVs. Across claims-based algorithms, PPVs were highest when a physician diagnosis or decision by adjudicators (confirmed and probable cases) was used as the gold standard and were lowest when American College of Rheumatology/European Alliance of Associations for Rheumatology 2010 criteria were applied. PPVs of claims-based algorithms for RA in patients aged ≥66 years were slightly higher versus a USA Medicare population (maximum PPVs of 95.0% and 88.9%, respectively).

CONCLUSION

VALIDATE-J demonstrated high PPVs for most claims-based algorithms for diagnosis of prevalent and incident RA using Japanese claims data. These findings will help inform appropriate RA definitions for future claims database research in Japan.

Factors associated with impaired physical function in elderly rheumatoid arthritis patients who had achieved low disease activity

OBJECTIVES

We aimed to investigate factors associated with impaired physical function [defined as Health Assessment Questionnaire Disability Index (HAQ-DI) >0.5] of old-old (aged 75-84 years) patients with rheumatoid arthritis.

METHODS

Data from 15,185 rheumatoid arthritis patients in the National Database of Rheumatic Disease in Japan were extracted from 2017 to 2018. We enrolled 3708 patients aged 55-84 years in Simplified Disease Activity Index (SDAI) ≤11 and Steinbrocker Stage I/II. Factors associated with HAQ-DI >0.5 were analysed by multivariable logistic regression.

RESULTS

About half of the old-old patients received methotrexate, which was lower than middle-aged (55-64 years) and young-old patients (65-74 years). The proportion of glucocorticoids in the old-old patients was highest among the three groups, and biological disease-modifying antirheumatic drugs were similarly used. The prevalence of HAQ-DI >0.5 was significantly higher in old-old patients with low disease activity than in those with remission. The same was true in the middle-aged and young-old patients. Multivariable analysis showed age, higher SDAI, glucocorticoid use, and methotrexate nonuse were significantly associated with HAQ-DI >0.5 in the old-old patients.

CONCLUSIONS

Achieving SDAI remission was an ideal goal for old-old patients in terms of physical function. Glucocorticoids and a low proportion of methotrexate use may influence the physical function of old-old patients.

Risk factors of acromial and scapular spine stress fractures differ by indication: a study by the ASES Complications of Reverse Shoulder Arthroplasty Multicenter Research Group

BACKGROUND

Both patient and implant related variables have been implicated in the incidence of acromial (ASF) and scapular spine fractures (SSF) following reverse shoulder arthroplasty (RSA); however, previous studies have not characterized nor differentiated risk profiles for varying indications including primary glenohumeral arthritis with intact rotator cuff (GHOA), rotator cuff arthropathy (CTA), and massive irreparable rotator cuff tear (MCT). The purpose of this study was to determine patient factors predictive of cumulative ASF/SSF risk for varying preoperative diagnosis and rotator cuff status.

METHODS

Patients consecutively receiving RSA between January 2013 and June 2019 from 15 institutions comprising 24 members of the American Shoulder and Elbow Surgeons (ASES) with primary, preoperative diagnoses of GHOA, CTA and MCT were included for study. Inclusion criteria, definitions, and inclusion of patient factors in a multivariate model to predict cumulative risk of ASF/SSF were determined through an iterative Delphi process. The CTA and MCT groups were combined for analysis. Consensus was defined as greater than 75% agreement amongst contributors. Only ASF/SSF confirmed by clinical and radiographic correlation were included for analysis.

RESULTS

Our study cohort included 4764 patients with preoperative diagnoses of GHOA, CTA, or MCT with minimum follow-up of 3 months (range: 3-84). The incidence of cumulative stress fracture was 4.1% (n = 196). The incidence of stress fracture in the GHOA cohort was 2.1% (n = 34/1637) compared to 5.2% (n = 162/3127) (P < .001) in the CTA/MCT cohort. Presence of inflammatory arthritis (odds ratio [OR] 2.90, 95% confidence interval [CI] 1.08-7.78; P = .035) was the sole predictive factor of stress fractures in GHOA, compared with inflammatory arthritis (OR 1.86, 95% CI 1.19-2.89; P = .016), female sex (OR 1.81, 95% CI 1.20-2.72; P = .007), and osteoporosis (OR 1.56, 95% CI 1.02-2.37; P = .003) in the CTA/MCT cohort.

CONCLUSION

Preoperative diagnosis of GHOA has a different risk profile for developing stress fractures after RSA than patients with CTA/MCT. Though rotator cuff integrity is likely protective against ASF/SSF, approximately 1/46 patients receiving RSA with primary GHOA will have this complication, primarily influenced by a history of inflammatory arthritis. Understanding risk profiles of patients undergoing RSA by varying diagnosis is important in counseling, expectation management, and treatment by surgeons.

Risk Factors for Thromboembolic and Bleeding Events in Patients After the Fontan Operation (Insights from the National Database of Health Insurance Claims of Japan)

Risk stratification of thromboembolic events (TEs) and bleeding events is important for the appropriate selection of thromboprophylaxis in patients after the Fontan operation. Therefore, we clarified the risk factors for TEs and bleeding events in patients after the Fontan operation using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. We conducted a retrospective cohort study including 2,515 patients who underwent the Fontan operation between June 2011 and September 2019. The end points were TEs and bleeding events within 1 year of the Fontan operation analysis. We analyzed the risk factors for these end points using a multivariate analysis. In total, 1,903 patients were included in the analysis. The median age at the time of the Fontan operation was 3 (1 to 22) years, and 1,067 patients (56%) were male. The incidence rates of TEs and bleeding events were 12% and 11%, respectively. Age (odds ratio [OR] 1.1 per 1 year older, p <0.05) was an independent risk factor for TEs. Thromboprophylaxis with aspirin after the Fontan operation significantly reduced TEs (OR 0.3, p <0.05). A history of postoperative hemorrhage (OR 1.5, p <0.05) and the use of a potassium channel blocker (OR 2.1, p <0.05) were independent risk factors for bleeding events. In conclusion, aspirin was found to reduce the risk of TEs within 1 year of the Fontan operation. The results of this study will be useful in selecting effective and safe thromboprophylaxis in patients after the Fontan operation.

Incidence of opportunistic infections in patients with rheumatoid arthritis treated with different molecular-targeted drugs: A population-based retrospective cohort study

OBJECTIVES

We compared the incidences of four opportunistic infections (OIs) in patients with rheumatoid arthritis (RA) treated with molecular-targeted drugs from big claims data.

MATERIALS AND METHODS

We identified 205,906 patients with RA who were prescribed molecular-targeted drugs in 2010-17 from the National Database of Japan and calculated the incidence of four OIs (Pneumocystis pneumonia, tuberculosis, nontuberculous mycobacterial infection, and herpes zoster).

RESULTS

The total number of Pneumocystis pneumonia, tuberculosis, nontuberculous mycobacterial infection, and herpes zoster patients with biological disease-modifying antirheumatic drugs or tofacitinib treatment history in RA was 765, 1158, 834, and 18,336, respectively. The incidence rates of each OI for all biological disease-modifying antirheumatic drugs were 0.14, 0.14, 0.09, and 2.40 per 100 person-years, respectively, while for tofacitinib they were 0.22, 0.22, 0.07, and 7.00 per 100 person-years. No big difference was observed among biological disease-modifying antirheumatic drugs. All OIs showed higher incidence in those >65 years, but Pneumocystis pneumonia, nontuberculous mycobacterial infection, and herpes zoster showed no difference between those 65-74 years old and those >75 years old. The median of occurrence was the third, seventh, ninth, and thirteenth month after treatment, respectively.

CONCLUSIONS

We counted real incidence rates of OIs for the whole nation from big claims data.

Economic burden of cancer attributable to modifiable risk factors in Japan

Controlling avoidable causes of cancer may save cancer-related healthcare costs and indirect costs of premature deaths and productivity loss. This study aimed to estimate the economic burden of cancer attributable to major lifestyle and environmental risk factors in Japan in 2015. We evaluated the economic cost of cancer attributable to modifiable risk factors from a societal perspective. We obtained the direct medical costs for 2015 from the National Database of Health Insurance Claims and Specific Health Checkups of Japan, and estimated the indirect costs of premature mortality and of morbidity due to cancer using the relevant national surveys in Japan. Finally, we estimated the economic cost of cancer associated with lifestyle and environmental risk factors. The estimated cost of cancer attributable to lifestyle and environmental factors was 1,024,006 million Japanese yen (¥) (8,460 million US dollars [$]) for both sexes, and ¥673,780 million ($5,566 million) in men and ¥350,226 million ($2,893 million) in women, using the average exchange rate in 2015 ($1 = ¥121.044). A total of ¥285,150 million ($2,356 million) was lost due to premature death in Japan in 2015. Indirect morbidity costs that could have been prevented were estimated to be ¥200,602 million ($1,657 million). Productivity loss was highest for stomach cancer in men (¥28,735 million/$237 million) and cervical cancer in women (¥24,448 million/$202 million). Preventing and controlling cancers caused by infections including Helicobacter pylori, human papillomavirus and tobacco smoking will not only be life-saving but may also be cost-saving in the long run.

Association between patient-reported outcomes and impairments in work and activity in patients with rheumatoid arthritis in clinical remission: A retrospective analysis using the IORRA database

OBJECTIVES

To explore the patient-reported outcomes (PROs) associated with work productivity and activity impairment (WPAI) in patients with rheumatoid arthritis (RA) in clinical remission.

METHODS

We enrolled patients with RA ≥18 years and with a simplified disease activity index ≤3.3 from the Institute of Rheumatology, Rheumatoid Arthritis data set collected in October 2017. The pain-visual analogue scale, patients' global assessment visual analogue scale (VAS), Japanese version of the Healthcare Assessment Questionnaire (J-HAQ) Disability Index, and duration of morning joint stiffness were selected as the PROs. To evaluate work productivity and activity, the WPAI for RA instrument (WPAI-RA) was used. To assess the contribution of each PRO to the WPAI-RA score, an analysis of variance model was constructed.

RESULTS

The mean age of the 2614 patients was 62.4 years; 85.1% were female. Median values of the WPAI-RA score were 1.1% for absenteeism, 6.5% for presenteeism, 7.4% for work impairment, and 10.2% for activity impairment. Morning joint stiffness contributed the most to absenteeism (18.0%), while pain-VAS contributed the most to presenteeism (57.4%), work productivity loss (51.1%), and daily activity impairment (53.7%). J-HAQ was the second most contributing factor to presenteeism (17.4%), work productivity loss (16.3%), and daily activity impairment (26.0%).

CONCLUSIONS

The pain-VAS and J-HAQ highly contributed to WPAI in patients with RA in clinical remission.

Patient-Physician Communication and Perception of Treatment Goals in Rheumatoid Arthritis: An Online Survey of Patients and Physicians

INTRODUCTION

To evaluate patient-physician communication and patients' understanding of treatment goals in rheumatoid arthritis (RA).

METHODS

A cross-sectional online survey of patients with RA and physicians treating RA was conducted between 16 and 30 June 2021. Participants were asked to rate the importance of 17 goals on a 6-point Likert scale, and mean scores were compared between patients and physicians by the Wilcoxon rank sum test. Patients' satisfaction with physician communication and their understanding of treatment goals were also assessed.

RESULTS

The responses of 502 patients and 216 physicians were analyzed. The most common patient age group was 50-59 years (28.5%), and the mean disease duration was 10.3 years. Physicians had a mean of 19.2 years of treatment experience and were treating a mean of 44.3 patients. Among the 17 goals assessed, patients placed significantly more importance on drug tapering or discontinuation as short-term goals (3-6 months) and on performing basic activities of daily living, being able to engage in daily tasks, achieving and maintaining remission, maintaining better laboratory values, and drug tapering or discontinuation as long-term goals (5-10 years; all adjusted p < 0.05). Patient treatment satisfaction was significantly associated with disease activity, a feeling of treatment effectiveness, satisfaction with physician communication, and agreement with physician goals.

CONCLUSION

Differences exist among patients with RA and physicians treating RA regarding the importance of short- and long-term treatment goals. Good patient-physician communication appears to be important for improving patient satisfaction.

TRIAL REGISTRATION

University Hospital Medical Information Network identifier: UMIN000044463.

Circulating DNA methylation level of CXCR5 correlates with inflammation in patients with rheumatoid arthritis

OBJECTIVES

To assess the differences in circulating DNA methylation levels of CXCR5 between rheumatoid arthritis (RA) and osteoarthritis (OA) and healthy controls (HC), and the correlation of methylation changes with clinical characteristics of RA patients.

METHODS

Peripheral blood samples were collected from 239 RA patients, 30 patients with OA, and 29 HC. Target region methylation sequencing to the promoter region of CXCR5 was achieved using MethylTarget. The methylation level of cg04537602 and methylation haplotype were compared among the three groups, and the correlation between methylation levels and clinical characteristics of RA patients was performed by Spearman's rank correlation analysis.

RESULTS

The methylation level of cg04537602 was significantly higher in the peripheral blood of RA patients compared with OA patients (p = 1.3 × 10^-3 ) and in the HC group (p = 5.5 × 10^{- 4} ). The sensitivity was enhanced when CXCR5 methylation level combined with rheumatoid factor and anti-cyclic citrullinated peptide with area under curve (AUC) of 0.982 (95% confidence interval 0.970-0.995). The methylation level of cg04537602 in RA was positively correlated with C-reactive protein (CRP) (r = .16, p = .01), and in RA patients aged 60 years and above, cg04537602 methylation levels were positively correlated with CRP (r = .31, p = 4.7 × 10^{- 4} ), tender joint count (r = .21, p = .02), visual analog scales score (r = .21, p = .02), Disease Activity Score in 28 joints (DAS28) using the CRP level DAS28-CRP (r = .27, p = 2.1 × 10^{- 3} ), and DAS28-ESR (r = .22, p = .01). We also observed significant differences of DNA methylation haplotypes in RA patients compared with OA patients and HC, which was consistent with single-loci-based CpG methylation measurement.

CONCLUSION

The methylation level of CXCR5 was significantly higher in RA patients than in OA and HC, and correlated with the level of inflammation in RA patients, our study establishes a link between CXCR5 DNA methylation and clinical features that may help in the diagnosis and disease management of RA patients.

Cost-effectiveness analyses of biologic and targeted synthetic disease-modifying anti-rheumatic diseases in patients with rheumatoid arthritis: Three approaches with a cohort simulation and real-world data

OBJECTIVE

To assess the cost-effectiveness of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) in rheumatoid arthritis.

METHODS

We conducted three analyses: a lifetime analysis with a cohort model (Study A) and two short-term analyses (Studies B and C). Study A evaluated the incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) gained from costs of standard treatments. Study B evaluated yearly costs per person achieving American College of Rheumatology (ACR) response (ACR20, ACR50, and ACR70), and Study C evaluated costs per person achieving previously defined claims-based effectiveness (equivalent to 28-joint Disease Activity Score ≤ 3.2). The proportion of ACR responders to the drugs of interest were determined by mixed treatment comparisons. Studies B and C estimated costs using a claims database.

RESULTS

In Study A, ICERs of all b/tsDMARDs were lower than 5.0 million Japanese yen (JPY) per QALY. In Study B, yearly costs per person with ACR50 response were lower for subcutaneous tocilizumab (TCZ-SC; 1.9 million JPY) and SC abatacept (2.3 million JPY). In Study C, costs per person were lower for TCZ-SC (1.3 million JPY) and intravenous TCZ (1.6 million JPY) and effectiveness rates were higher for intravenous TCZ (45.3%) and infliximab (43.0%).

CONCLUSION

The b/tsDMARDs with lower prices showed higher cost-effectiveness.

Influence of concomitant methotrexate use on the clinical effectiveness, retention, and safety of abatacept in biologic-naïve patients with rheumatoid arthritis: Post-hoc subgroup analysis of the ORIGAMI study

OBJECTIVES

We performed post-hoc analyses of the ORIGAMI study to investigate whether concomitant methotrexate (MTX) influences the clinical outcomes of abatacept in biologic-naïve patients with rheumatoid arthritis.

METHODS

Enrolled patients (n = 325) were divided into two groups according to whether abatacept was prescribed without (MTX-) or with (MTX+) concomitant MTX. We compared the changes in Simplified Disease Activity Index (SDAI), Disease Activity Score-28 with C-reactive protein (DAS28-CRP), and Japanese Health Assessment Questionnaire (J-HAQ) through to 52 weeks of treatment, the abatacept retention rate, and safety.

RESULTS

At Week 52, the mean SDAI (8.9 vs. 8.8), DAS28-CRP (2.6 vs. 2.6), and J-HAQ (0.92 vs. 0.91) scores were comparable in the MTX- (n = 129) and MTX+ (n = 150) groups. Multivariable logistic regression revealed no significant association between MTX use and SDAI (low disease activity) or J-HAQ (minimum clinically important difference). The abatacept retention rates, estimated using the Kaplan-Meier method, were 73.2% and 66.7% in the MTX- and MTX+ groups, respectively. Adverse events occurred in 47.5% (of 139) and 52.2% (of 159) of patients in the MTX- and MTX+ groups, respectively.

CONCLUSION

The effectiveness and safety of abatacept appeared comparable with or without concomitant MTX in this real-world clinical setting.

A Real-World Claims Database Study Assessing Long-Term Persistence with Golimumab Treatment in Patients with Rheumatoid Arthritis in Japan

INTRODUCTION

The persistence of golimumab (GLM) treatment in Japanese patients with rheumatoid arthritis (RA) has been evaluated previously, but evidence of long-term real-world use is lacking. This study assessed the long-term persistence of GLM use, its influencing factors, and impact of prior medications in patients with RA in actual clinical practice in Japan.

METHODS

This is a retrospective cohort study of patients with RA using data from a hospital insurance claims database in Japan. The identified patients were stratified as only GLM treatment (naïve), had one biological disease-modifying anti-rheumatic drug (bDMARD)/Janus kinase (JAK) inhibitor treatment prior to GLM [switch (1)] and had at least two bDMARDs/JAK prior to GLM treatment [switch (≥ 2)]. Patient characteristics were evaluated using descriptive statistics. Kaplan-Meier survival and Cox regression methods were used to analyze GLM persistence at 1, 3, 5, and 7 years and the associated factors. Treatment differences were compared using a log-rank test.

RESULTS

GLM persistence rate in the naïve group was 58.8%, 32.1%, 21.4%, and 11.4% at 1, 3, 5, and 7 years, respectively. Overall persistence rates in the naïve group were higher than in switch groups. Higher GLM persistence was observed among patients aged 61-75 years and those concomitantly using methotrexate (MTX). Also, women were less likely to discontinue treatment compared to men. Higher Charlson Comorbidity Index score, initial GLM dose of 100 mg, and switch from bDMARDs/JAK inhibitor were related to a lower persistence rate. As a prior medication, infliximab showed the longest persistence for subsequent GLM, and using this as a reference, tocilizumab, sarilumab, and tofacitinib subgroups had significantly shorter persistence, respectively (p = 0.001, 0.025, 0.041).

CONCLUSION

This study presents the long-term real-world results for persistence of GLM and its potential determinants. These most recent and long-term observations demonstrated that GLM and other bDMARDs continue to benefit patients with RA in Japan.

Treatment in Patients with Psoriatic Disease and Rheumatoid Arthritis: Seven Case Reports

The incidence of psoriasis, an intractable long-lasting inflammatory skin disease, is increasing and has many complications and comorbidities. Approximately 14% of patients have psoriatic arthritis (PsA). Rheumatoid arthritis (RA) is not a rare disease worldwide, and some patients may have both PsA and RA. In the present study, we encountered seven patients with concurrent diagnoses of RA and psoriatic disease and reported the details of clinical data, treatment efficacy, and X-ray findings. The diagnosis may require not only classification criteria but also a comprehensive judgment in collaboration with rheumatology over time. In addition to methotrexate as an anchor drug, anti-tumor necrosis factor-α agents are the first choice of biological agents for treatment, and interleukin (IL)-17 inhibitors may be effective, as IL-17 is also involved in the pathogenesis of RA. When treating patients with both PsA and RA, it may be essential to consider the treatment strategy, depending on which disease is more active.

Seasonal exacerbation of rheumatoid arthritis detected by big claims data analysis: A retrospective population study

OBJECTIVES

The objective of the study was to determine the seasonal changes in the initiation of biological disease-modifying antirheumatic drugs (bDMARDs) and methotrexate (MTX) using big claims data.

METHODS

We counted the monthly number of initial administrations of each bDMARD and MTX in patients with rheumatoid arthritis (RA) between April 2010 and March 2017. Data were collected from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. This database covers more than 95% of Japanese citizens. Seasonal changes in the number of initiations were determined. Patient claims were also classified according to drugs, districts, gender, and ages.

RESULTS

The initiation of bDMARDs and MTX administration varied according to the season in a sine curve shape, with the highest numbers in May to July and the lowest numbers in November to January. The same changing pattern was observed among each bDMARD, district, gender, and age groups particularly when the number was on the higher side.

CONCLUSION

We noted an apparent seasonal change in the number of bDMARDs initiated, with a peak during spring, suggesting an exacerbation of RA in the spring in Japan. These changes are overlooked in daily practice and are only visible using big data.

Late-onset rheumatoid arthritis registry study, LORIS study: study protocol and design

BACKGROUND

Although drug treatment strategies for rheumatoid arthritis (RA) are relatively well established, there is a paucity of evidence on the treatment in older patients. The purpose of this study is to build a registry for late-onset RA (LORA), which is expected to increase rapidly worldwide. In addition, we aim to propose optimal treatment strategies according to the patient background including frailty, thereby contributing to improving the quality of treatment and daily living in patients with RA.

METHODS/DESIGN

The LORIS (Late-onset Rheumatoid Arthritis Registry) Study is a prospective nation-wide multicenter observational study of patients with LORA. The inclusion criteria were patients aged ≥ 65 years at onset, meeting 2010 ACR/EULAR classification criteria for RA, and starting either any disease-modifying antirheumatic drugs (DMARDs) in a DMARD-naïve patient or the first biologic/targeted synthetic DMARDs during the study period. Enrollment was started on 11 January, 2022 and will be closed on 31 December, 2023. Patients will undergo a comprehensive baseline assessment including clinical data, medication, cognitive and physical function, psychosocial factors, and frailty. Data will be collected at baseline, Month 3, 6, 12, 18, 24, 36, and summarized descriptively. The factors associated with adverse events and achieving remission will be determined.

DISCUSSION

A multi-disciplinary panel including patients, rheumatologists, and geriatric specialists will discuss the results and build a consensus regarding the treatment goals of LORA. We expect to provide a broad range of information for evidence-based shared decision making in the treatment of LORA.

STUDY REGISTRATION

Registered at the UMIN registry (UMIN000046086) on 1 January 2022.

Understanding the Actual Use of Anti-HIV Drugs in Japan from 2016 to 2019: Demonstrating Epidemiological Relevance of NDB Open Data Japan for Understanding Japanese Medical Care

The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data Japan is helpful for attaining simple and comprehensive understanding of medical care in Japan. Herein, we investigated the transition of anti-HIV-drug use in Japan over a 4-year period from fiscal year (FY) 2016 to FY 2019 using data on anti-HIV drugs that were extracted from the 3rd, 4th, 5th, and 6th NDB Open Data Japan. Then, the data were stratified by mechanism of action, single-tablet regimen (STR) or non-STR, age groups, and sex and analyzed. Throughout the study period, the prescription volume for tenofovir alafenamide fumarate as the backbone drug and integrase strand transfer inhibitors as the anchor drug increased. In FY 2019, STRs constituted approximately 44% of the total combination antiretroviral therapy regimens, 1.6 times higher than that in FY 2016 (27%). With the advent of newer drugs and regimens, the differences in anti-HIV drugs prescribed to patients of different ages and sex gradually diminished; however, differences were unremarkable in the first period, especially between sexes. The NDB Open Data Japan made it relatively easy to evaluate recent trends in anti-HIV prescription in Japan, indicating its usefulness for continuous surveys in this field.

Safety and Effectiveness of Baricitinib for Rheumatoid Arthritis in Japanese Clinical Practice: 24-Week Results of All-Case Post-Marketing Surveillance

OBJECTIVES

To assess safety and effectiveness of baricitinib treatment for rheumatoid arthritis (RA) in real-world clinical practice.

METHODS

This ongoing all-case post-marketing surveillance study (starting September 2017) includes all patients with RA treated with baricitinib in Japan. Safety and effectiveness (disease activity) were assessed for 24 weeks.

RESULTS

Safety analyses to February 2021 included 4731 patients (initial baricitinib dose: 4 mg/day, n=3058; 2 mg/day, n=1661; other, n=12); 1059 (22.38%) were ≥75 years, and 3362 (71.06%) previously received biologic therapy. Overall observational period was 1863.14 patient-years; 1174 (24.82%) patients discontinued baricitinib before Week 24, mostly for lack of effectiveness (n=478; 10.10%). Adverse events occurred in 1271 (26.87%) patients (serious: 203 [4.29%]; death: 18 [0.38%]). The incidence of herpes zoster, hepatic function disorder, and serious infection was 3.09%, 2.77%, and 1.90%, respectively. Malignancy occurred in 17 patients (0.36%) and major adverse cardiovascular events in seven patients (0.15%). Among patients with effectiveness data, at least 26.57% (Boolean) achieved remission at Week 24.

CONCLUSIONS

This large nationwide surveillance study evaluated the safety and effectiveness of 24 weeks of baricitinib for RA in real-world clinical practice. Continued surveillance of long-term safety is ongoing.

Safety and Efficacy of Filgotinib for Japanese Patients with RA and Inadequate Response to MTX: FINCH 1 52-Week Results and FINCH 4 48-Week Results

OBJECTIVE

To present safety and efficacy of the JAK1 preferential inhibitor filgotinib in Japanese patients with prior inadequate response (IR) to methotrexate (MTX) from a 52-week randomised controlled parent study (PS) and long-term extension (LTE) through June 2020.

METHODS

The PS (NCT02889796) randomised MTX-IR patients to filgotinib 200 (FIL200) or 100 mg (FIL100), adalimumab (ADA) 40 mg, or placebo; all took stable background MTX. At week (W) 24, placebo patients were rerandomised to FIL200 or FIL100. The primary endpoint was W12 American College of Rheumatology 20% improvement (ACR20); safety was assessed by adverse event (AE) reporting. For the LTE (NCT03025308), eligible filgotinib patients continued FIL200/FIL100; ADA patients were rerandomised (blinded) to FIL200 or FIL100; all continued MTX.

RESULTS

114/147 Japanese patients completed the PS; 115 enrolled in LTE; 103 remained on study in June 2020. In the PS, AEs were consistent with the overall population, and W24 efficacy was maintained or improved through W52, comparable with the overall population. LTE AE incidences were similar between doses; filgotinib efficacy was consistent from baseline to W48 and similar between PS ADA and filgotinib patients.

CONCLUSION

Among MTX-IR Japanese patients, filgotinib maintained efficacy over 1 year; LTE safety was consistent with the PS.

Safety and Effectiveness of Certolizumab Pegol in Japanese Patients with Rheumatoid Arthritis: Results from a 24-Week Post-Marketing Surveillance Study

OBJECTIVES

To report 24-week safety and effectiveness data of certolizumab pegol (CZP) in Japanese patients with rheumatoid arthritis (RA) from a post-marketing surveillance study.

METHODS

Enrolled patients were newly receiving CZP. All adverse events (AEs) and adverse drug reactions (ADRs) were recorded for patients who received ≥1 CZP dose. Effectiveness outcomes included: 28-joint Disease Activity Score with erythrocyte sedimentation rate (DAS28-ESR) and EULAR response. Missing data were imputed using last observation carried forward.

RESULTS

3,727 patients were enrolled; safety and effectiveness were evaluated in 3,586 and 1,794 patients, respectively. 24.9% of patients reported AEs (n=893/3,586) and 14.7% reported ADRs (528/3,586). Serious AEs and serious ADRs were reported in 8.3% (298/3,586) and 5.3% (190/3,586), respectively. Selected serious ADRs of interest included infections (n=110; 3.1%), tuberculosis (6; 0.2%), interstitial pneumonia (15; 0.4%), malignancy (8; 0.2%) and hepatic function disorder (7; 0.2%). No allergic reactions, autoimmune disease, cardiac failure, demyelinating diseases or pancytopenia were reported. Mean DAS28-ESR reduced from 4.8 (baseline) to 3.4 (final evaluation). At final evaluation, 34.7% of patients achieved EULAR good response.

CONCLUSIONS

These real-world safety and effectiveness results were consistent with previously reported data, with no new safety signals identified. Long-term, real-world CZP safety and effectiveness data are needed.

Indigenous Nigeria medicinal herbal remedies: A potential source for therapeutic against rheumatoid arthritis

Rheumatoid arthritis (RA) is a debilitating disease associated with locomotion impairment, and conventional therapeutic drugs are not optimal for managing RA. There is an avalanche of medications used for the management of RA. Still, studies have shown that they are associated with severe side effects, including hepatotoxicity, retinopathy, and cardiotoxicity disorders of the central nervous system (CNS), skin, blood, and infections. Complementary and alternative medicine (CAM) is currently gaining attention as a novel panacea for managing debilitating diseases, such as RA. Nigerian folk herbal remedies are replete with a plethora of curative medicine, albeit unvalidated scientifically but with seemingly miraculous provenance. Studies of the identification of bioactive compounds present in these botanicals using advanced spectral analytical techniques have enhanced our understanding of the role of Nigerian herbal remedies in the treatment and management of RA. Interestingly, experimental studies abound that the bioactive compounds present in the extracts of plant botanicals protected animals from the development of RA in different experimental models and reduced the toxicity associated with conventional therapeutics. Validated mechanisms of RA amelioration in human and animal models include suppression of the expression of NF-κB, IL-1β, TNF-α, IL-6, IL-8, IL-17, IL-23, chemokines, TGF-β, RANKL, RANK, iNOS, arginase, COX-2, VEGFA, VEGFR, NFATC1, and TRAP in the synoviocytes. Decreased ROS, NO, MDA, carbonyl groups, and PGE₂ in the synovial fluid increased the expression of PPARα/γ; antioxidant and anti-inflammatory molecules also improve RA etiology. In this mini-review, we discuss the global burden of RA, the novel role of plant-based botanicals as potential therapeutics against signaling pathways in RA. Also addressed is the possible repurposing/reprofiling of plant botanicals to increase their therapeutic index among RA patients that patronize traditional healers in Nigeria with a global projection.

Unincreased risk of hospitalized infection under targeted therapies versus methotrexate in elderly patients with rheumatoid arthritis: a retrospective cohort study

Background

Infection is one of the primary concerns during treatment for rheumatoid arthritis (RA) in elderly patients. However, infection risk of patients with RA receiving targeted therapy (TT) including biological disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitors (JAKIs) in elderly patients are scarce. The aim of this study was to compare the risk of hospitalized infection (HI) with TT versus methotrexate (MTX) therapy among young, elderly, and older elderly patients with RA.

Methods

Using Japanese claims data, patients satisfying the following criteria were enrolled: (1) ≥ one ICD10 code for RA; (2) ≥ one prescription of MTX or TT (bDMARDs and JAKIs) between April 2008 and September 2018; and (3) ≥16 years old. We calculated the incidence rate (IR) of HI per 100 patient-years in the young, elderly, and older elderly groups (those aged 16–64, 65–74, and ≥75 years, respectively) and the IR ratio (TT vs. MTX) of HI. A logistic regression model was used to estimate the associations between HI and TT versus MTX in each group.

Results

The overall IR of HI per 100 patient-years (95% confidence interval) was 3.2 [2.9–3.5], 5.0 [4.6–5.4], and 10.1 [9.5–10.9] in the young, elderly, and older elderly groups, respectively. Concomitant use of MTX or immunosuppressive DMARDs with TT was less frequent in the elderly and older elderly groups. The adjusted odds ratio of TT vs. MTX for HI was 1.3 (1.0–1.7; p = 0.021), 0.79 (0.61–1.0; p = 0.084), and 0.73 (0.56–0.94; p = 0.015) in the young, elderly, and older elderly groups, respectively.

Conclusion

The overall IR of HI was increased with age. The risk of HI under TT compared to MTX was not elevated in elderly and older elderly patients after adjusting for patients’ characteristics and concomitant treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02807-9.

A Retrospective, Longitudinal Study of Rheumatoid Arthritis Treatment Patterns with Janus Kinase Inhibitors and Other Disease-Modifying Antirheumatic Drugs in Japan

OBJECTIVES

There is limited information on the clinical use of Janus kinase inhibitors (JAKis) for rheumatoid arthritis (RA) treatment in Japan. The aim of this study was to identify disease-modifying antirheumatic drug (DMARD) treatment patterns in Japan.

METHODS

This retrospective, longitudinal study extracted data from the Japan Medical Data Center database. Patients with RA diagnosis were enrolled 2016-2019, during which patients had a first prescription of a major DMARD, split into six mutually exclusive classes: methotrexate (MTX); other conventional synthetic (cs)DMARDs; tumor necrosis factor alpha (TNFα) inhibitors; cytotoxic T-lymphocyte-associated antigen-4-immunoglobulin; anti-interleukin-6 receptor therapies; and JAKis. The primary objective was to describe DMARD treatment patterns, especially for JAKis.

RESULTS

Overall, 10,399 patients were included in the analysis. The most common treatments were MTX, other csDMARDs, and TNFα inhibitors. The total number of JAKi prescriptions increased approximately eight-fold during 2016-2019. Most (61.1%) patients who received JAKis had prior MTX or TNFα inhibitor treatment. JAKi treatment duration was longer than for biologics and other csDMARDs, and comparable to that of MTX.

CONCLUSIONS

The sequence of drug class prescriptions for RA in Japan during 2016-2019 followed clinical guidelines. Over this period, JAKis were increasingly used as second-line treatment following MTX.

Influence of frailty on patient global assessment in rheumatoid arthritis

AIM

Patient Global Assessment (PtGA; range 0-10 cm) is an important indicator of clinical outcomes, including physical function, in self-assessment of patients with rheumatoid arthritis (RA). Frailty is a concept that encompasses not only physical, but also mental, psychological and social vulnerability. This study aimed to investigate the influence of frailty on PtGA in patients with RA.

METHODS

Among 581 patients with RA who completed a questionnaire survey on frailty between June and August 2020, 559 who completed the Kihon Checklist (KCL; a 25-item questionnaire with seven domains) were included. The proportion of patients with PtGA ≤1 was compared between the frailty (KCL score ≥8), pre-frailty (KCL score 4-7) and robust (KCL score 0-3) groups. Factors associated with PtGA ≤1 were examined using multivariate logistic regression models.

RESULTS

Of the 559 patients, 221 (39.5%) had frailty. The proportion of patients with PtGA ≤1 was significantly lower in the frailty group (33.9%) than in the robust (65.4%, P < 0.001) and pre-frailty (55.7%, P < 0.001) groups. Multivariate analysis revealed that frailty (vs robust, OR 0.37, 95% CI 0.22-0.69), as well as disease duration and tender joint count, were factors independently associated with PtGA ≤1. When each domain of the KCL was examined, activities of daily living, physical strength, isolation and depressive mood were factors associated with PtGA ≤1.

CONCLUSION

Frailty affects PtGA in patients with RA. As frailty impacts the physical, mental and social vulnerability aspects of PtGA, a multifaceted approach, including inflammation suppression, is required to improve PtGA in patients with RA. Geriatr Gerontol Int 2022; 22: 399-404.

Inflammation and Bone Metabolism in Rheumatoid Arthritis: Molecular Mechanisms of Joint Destruction and Pharmacological Treatments

Rheumatoid arthritis (RA) is an inflammatory disease characterized by a variety of symptoms and pathologies often presenting with polyarthritis. The primary symptom in the initial stage is joint swelling due to synovitis. With disease progression, cartilage and bone are affected to cause joint deformities. Advanced osteoarticular destruction and deformation can cause irreversible physical disabilities. Physical disabilities not only deteriorate patients’ quality of life but also have substantial medical economic effects on society. Therefore, prevention of the progression of osteoarticular destruction and deformation is an important task. Recent studies have progressively improved our understanding of the molecular mechanism by which synovitis caused by immune disorders results in activation of osteoclasts; activated osteoclasts in turn cause bone destruction and para-articular osteoporosis. In this paper, we review the mechanisms of bone metabolism under physiological and RA conditions, and we describe the effects of therapeutic intervention against RA on bone.

Systematic review for the treatment of older rheumatoid arthritis patients informing the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis

OBJECTIVES

To provide an evidence base for clinical practice guidelines (CPG) for the management of rheumatoid arthritis (RA) in older adults.

METHODS

PubMed, Cochrane library, and Japan Centra Revuo Medicina databases were searched for articles published between 1990 and 2019. Quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system, with some modifications.

RESULTS

Among 702 identified articles, there were 5 post-hoc analyses of randomized controlled trials and 10 observational studies. Meta-analysis of the former yielded a mean difference of the van der Heijde-modified total Sharp score of -2.79 (95% confidence interval [CI] - 3.74 to -1.84) for treatment with tumor necrosis factor inhibitors. The risk ratio (RR) for the American College of Rheumatology 50% response rate, and for serious adverse events was 2.83 (95%CI 1.90-4.21) and 1.32 (95%CI 0.53-3.31), respectively, for Janus kinase inhibitors. Meta-analysis of the observational studies yielded an RR for disease activity score-28 remission and serious infections of 0.76 (95%CI 0.64-0.91) and 1.92 (95%CI 1.31-2.81) for older-versus-younger patients receiving biological disease-modifying antirheumatic drugs, respectively.

CONCLUSION

This systematic review provides the necessary evidence for developing CPG for the management of RA in older adults.

Geographic variations in rheumatoid arthritis treatment in Japan: A nationwide retrospective study using the national database of health insurance claims and specific health checkups of Japan

OBJECTIVES

To characterize the treatments for rheumatoid arthritis (RA) among institution types and prefectures in Japan.

METHODS

Using the National Database of Health Insurance Claims and Specific Health Checkups of Japan in the 2017 fiscal year, we investigated disease-modifying antirheumatic drug (DMARD) and oral corticosteroid prescription trends across 825 thousand RA patients. These data were compared between specialized and non-specialized institutions and by prefecture. RA specialized institutions (SIs) were defined as either institutions registered in the rheumatology training program at the Japan College of Rheumatology or institutions where board-certified rheumatologists were employed.

RESULTS

The overall percentage of patients who never visited an SI was 31.8% and increased with age (16-29 years old = 15.6%; ≥80 years = 42.8%). In twelve prefectures (25.5%), the proportions of patients who never visited an SI were at least 10% higher than the overall average. The proportions of patients who only visited SIs and were prescribed methotrexate and biological DMARDs were ranged from 51.9-72.9% and 19.5-33.2%, respectively. However, those of patients who had never visited an SI and were prescribed those medications were 44.0-71.6% and 7.2-28.0%, respectively.

CONCLUSIONS

This is the first study evaluating the trends in RA treatments by prefecture and institution specialty by using the NDB Japan. Opportunities of patients with RA for visiting SI was unevenly distributed in Japan, affecting some aspects of treatment provided.

Effect of Foot Orthosis Treatment on Quality of Life in Secondary Sarcopenia Patients with Rheumatoid Arthritis-Related Foot Impairment

Objectives:

Patients with rheumatoid arthritis (RA)-related foot impairment have a high rate of sarcopenia. Treatment using a foot orthosis (FO) enables not only a reduction in pain while walking but also an increase in physical activity, helping to prevent further loss of muscle mass. However, the primary goal of treating RA is to maximize patients’ long-term quality of life (QOL). We investigated whether FO treatment both increases physical activity and improves QOL.

Methods:

Among 31 patients with RA-related foot impairment, 15 with sarcopenia were treated with an FO for 6 months. Foot-specific QOL (measuring using the Self-Administered Foot Evaluation Questionnaire), foot pain, activities of daily living, and physical activity (walking-intensity activity and moderate- to vigorous-intensity activity) were compared before treatment and after 6 months of treatment.

Results:

Ten patients who completed 6 months of follow-up were analyzed. Significant QOL improvements were found in the Pain and Pain-Related category and the Physical Functioning and Daily Living category (P = 0.02–0.04); however, no significant changes were found in the Social Functioning, General Health and Well-Being, or Shoe-Related categories (P = 0.09–0.21). Foot pain and activities of daily living significantly improved (P = 0.01–0.04). Physical activity significantly increased for walking-intensity activity (P = 0.04) but did not change for moderate- to vigorous-intensity activity (P = 1.00).

Conclusions:

FO treatment in patients with RA-related foot impairment and sarcopenia increased light-intensity physical activity such as walking and improved physical QOL.

Trend in Prescription and Treatment Retention of Molecular-Targeted Drugs in 121,131 Japanese Patients With Rheumatoid Arthritis: A Population-Based Real-World Study

OBJECTIVES

To describe the real-world prescription and treatment retention of molecular-targeted drugs for rheumatoid arthritis (RA) in Japan.

MATERIALS AND METHODS

204,416 patients with RA prescribed at least one of the eight molecular-targeted drugs in 7 years from the National Database of Health Insurance Claims and Specific Health Checkups of Japan covering 98.3% of the Japanese population. The retention rate of each drug as well as head-to head comparisons were estimated by Kaplan-Meier method.

RESULTS

121,131 RA patients were prescribed any molecular-targeted drug for the first time, while 36,633 uses of molecular-targeted drug switched from another (switch use). The overall retention rates of molecular-targeted drugs at 12, 36, and 60 months were 0.64, 0.42, and 0.32 for the naïve use and 0.59, 0.40, and 0.31 for the switch use, respectively. Non-tumor necrosis factor (TNF)-inhibitor molecular-targeted drugs, particularly tocilizumab and tofacitinib, had higher retention rates than TNF inhibitors for both naïve and switch uses regardless of the previous drug, and showed higher retention rates in head-to-head comparisons between eight molecular-targeted drugs.

CONCLUSIONS

Our data reveal that the real-world drug retention is overall lower than previously reported and higher with non-TNF inhibitors than with TNF inhibitors.

Treatment strategies for elderly-onset rheumatoid arthritis in the new era

Elderly-onset rheumatoid arthritis (EORA) is characterized by acute onset and clinical features of high disease activity. Anti-cyclic citrullinated peptide antibody (ACPA) positivity or the presence of bone erosions predicts a radiological joint destruction of EORA, but ACPA-negative EORA with a polymyalgia rheumatica (PMR) phenotype may also present. Biological disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase inhibitors were beneficial both in older and in younger patients in terms of risk-benefit balance. Implementation of a treat-to-target strategy could improve EORA outcomes, but older patients have more age-related comorbidities and interstitial lung disease than younger patients. Baseline comorbidities, more frequent methotrexate dose-dependent adverse events, serious infections, cardiovascular disease events, and malignancy all influence the choice of treatment and the treatment goals for older patients. Based on articles reviewed here, it is suggested that current treatment strategies for younger patients are also useful for ACPA-positive EORA and for ACPA-negative EORA with bone erosion. Differential diagnosis of ACPA-negative EORA without erosive arthritis and PMR with peripheral manifestations is challenging, and the treatment strategy of patients presenting with this overlap phenotype remained unclear. An appropriate treatment strategy for all patients with EORA still needs to be developed.

Effectiveness and safety of subcutaneous abatacept in biologic-naïve RA patients at Week 52: A Japanese multicentre investigational study (ORIGAMI study)

OBJECTIVES

To evaluate the effectiveness and safety of abatacept over 52 weeks in biologic-naïve rheumatoid arthritis (RA) patients with moderate disease activity in the prospective, 5-year, observational study (ORIGAMI study) in Japan.

METHODS

Abatacept (125 mg) was administered subcutaneously once a week. Clinical outcomes included Simplified Disease Activity Index (SDAI) remission at Week 52 (primary endpoint), Japanese Health Assessment Questionnaire (J-HAQ), EuroQol 5-Dimension Questionnaire (EQ-5D), treatment retention, and safety. The results were compared with those of conventional synthetic disease-modifying antirheumatic drug (csDMARD) controls from the ongoing Institute of Rheumatology, Rheumatoid Arthritis (IORRA) registry.

RESULTS

Overall, 325 patients were enrolled, with a mean age of 66.9 ± 12.7 years. The proportion of patients achieving SDAI remission (≤3.3) at Week 52 was 18.9% (95% CI: 14.3-23.6) and low disease activity (≤11) was 53.3% (95% CI: 47.4-59.1). A significant improvement was observed in J-HAQ and EQ-5D over 52 weeks in both the abatacept and csDMARD groups. The probability of abatacept treatment retention at Week 52 was 69.9% (95% CI: 64.7-75.5). Adverse events and serious adverse events were reported in 50.0% and 12.1% of patients, respectively.

CONCLUSIONS

Abatacept significantly improved disease activity, physical disability, and quality of life for up to 52 weeks in RA patients in a real-world setting.

Long-term safety and effectiveness of abatacept in Japanese patients with rheumatoid arthritis: 3-year follow-up of a postmarketing surveillance

OBJECTIVES

To analyse the long-term safety and effectiveness of abatacept for rheumatoid arthritis using real-world, Japanese, postmarketing surveillance data, focusing on serious infections and malignancies as priority events.

METHODS

This 3-year, multicentre surveillance registered patients undergoing abatacept treatment by intravenous infusion between July 2011 and October 2012.

RESULTS

The safety and effectiveness analysis sets included 647 and 596 patients, respectively. The total observation period for the safety analysis was 1280 patient-years. Over the 3-year follow-up, the incidence rates of adverse drug reactions (ADRs) and serious ADRs were 19.92 per 100 patient-years (22.87% of patients) and 4.06 per 100 patient-years (6.65% of patients), respectively. Infections and infestations were the most common ADRs (14.68%), followed by respiratory, thoracic, and mediastinal disorders (3.09%). Incidence rates of serious infections as ADRs and malignancy as adverse events were 1.95 and 1.02 per 100 patient-years, respectively. Retention rates at 1 and 3 years were 67.4% and 43.9%, respectively. Significant decreases from baseline were observed in Disease Activity Score (DAS) 28-erythrocyte sedimentation rate and DAS28-C-reactive protein, as well as Health Assessment Questionnaire-Disability Index (HAQ-DI) and modified HAQ scores.

CONCLUSIONS

No new safety signals were detected during the 3-year observation period and effectiveness was maintained over time.

Impact of age on the efficacy and safety of peficitinib (ASP015K) for the treatment of rheumatoid arthritis

OBJECTIVES

To evaluate peficitinib efficacy and safety in Asian patients with rheumatoid arthritis (RA), stratified by age (≥20-<50, ≥50-<65, and ≥65 years).

METHODS

Efficacy data from two Phase 3 studies were analysed. Safety data from one Phase 2, two Phase 3, and one open-label extension study were pooled. Incidence rates per 100 patient-years of adverse events of special interest were calculated, and Cox proportional hazard analysis was conducted.

RESULTS

1052 patients received peficitinib for 2 years (median). Peficitinib demonstrated efficacy improvements versus placebo across all age categories. Incidence rates (95% confidence interval) per 100 patient-years for ≥20-<50, ≥50-<65, and ≥65 years were 0.8 (0.4, 1.9), 2.6 (1.8, 3.7), and 4.7 (3.1, 7.0) for serious infections and 3.7 (2.5, 5.4), 6.4 (5.0, 8.2), and 11.2 (8.5, 14.7) for herpes zoster-related disease, respectively. Twenty patients reported malignancies in pooled Phase 2/3 studies. Incidences of serious infections and herpes zoster-related disease increased significantly with age, but there was no association with baseline estimated glomerular filtration rate.

CONCLUSIONS

Peficitinib was efficacious in adult Asian RA patients of all ages. Age, but not estimated glomerular filtration rate, was associated with serious infections and herpes zoster-related disease, demonstrating the importance of an appropriate RA treatment strategy in older patients.

Impact of the HLA-DRB1 shared epitope on responses to treatment with tofacitinib or abatacept in patients with rheumatoid arthritis

Objectives

The aim of this study was to compare the clinical effectiveness of tofacitinib and abatacept and clarify the impact of the HLA-DRB1 shared epitope (SE) on responses to these treatments in patients with rheumatoid arthritis (RA).

Methods

After adjustments by propensity score matching, 70 out of 161 patients receiving tofacitinib and 70 out of 131 receiving abatacept were extracted. The clinical effectiveness of both drugs over 24 weeks and the impact of the copy numbers of SE on effectiveness outcomes were investigated.

Results

The percentage of patients in remission in the 28-joint count disease activity score using the erythrocyte sedimentation rate (DAS28-ESR) did not significantly differ between patients receiving tofacitinib and abatacept at week 24 (32% vs 37%, p = 0.359). The mean change at week 4 in DAS28-ESR from baseline was significantly greater in patients receiving tofacitinib than in those receiving abatacept (− 1.516 vs − 0.827, p = 0.0003). The percentage of patients in remission at week 4 was 30% with tofacitinib and 15% with abatacept (p = 0.016). When patients were stratified by the copy numbers of SE alleles, differences in these numbers did not affect DAS28-ESR scores of patients receiving tofacitinib. However, among patients receiving abatacept, DAS28-ESR scores were significantly lower in patients carrying 2 copies of SE alleles than in those carrying 0 copies at each time point throughout the 24-week period. Furthermore, the percentage of patients in remission with DAS28-ESR at week 24 was not affected by the copy numbers of SE alleles in patients receiving tofacitinib (p = 0.947), whereas it significantly increased as the copy numbers became higher in patients receiving abatacept (p = 0.00309). Multivariable logistic regression analyses showed a correlation between the presence of SE and DAS28-ESR remission in patients receiving abatacept (OR = 25.881, 95% CI = 3.140–213.351, p = 0.0025), but not in those receiving tofacitinib (OR = 1.473, 95% CI = 0.291–7.446, p = 0.639).

Conclusions

Although the clinical effectiveness of tofacitinib and abatacept was similar at week 24, tofacitinib was superior to abatacept for changes from baseline in DAS28-ESR and the achievement of remission at week 4. SE positivity was associated with the achievement of DAS28-ESR remission by week 24 in patients receiving abatacept, but not in those receiving tofacitinib.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02612-w.

Patient Preference for Treatment Mode of Biologics in Rheumatoid Arthritis: A 2020 Web-based Survey in Japan

Introduction

Although the proportion of patients with rheumatoid arthritis (RA) using biologic disease-modifying antirheumatic drugs (bDMARDs) has increased steadily, the relationship between patient background and preference for bDMARDs has not been fully investigated.

Methods

We conducted a web-based questionnaire survey among patients aged ≥ 20 years with RA receiving bDMARDs. Participants were recruited through an internet research company in Japan. Study endpoints included factors affecting the preferred bDMARD treatment mode, namely, in-hospital intravenous infusion (infusion), in-hospital subcutaneous injection (in-hospital injection), or self-administered subcutaneous injection (self-injection), and discrepancies between the current and preferred treatment mode.

Results

Of the 400 patients surveyed for preferred treatment mode, 15.3% preferred infusion, 18.0% preferred in-hospital injection, and 66.8% preferred self-injection. A preference for infusion (odds ratio [OR] 2.218 and 6.165) and in-hospital injection (OR 4.735 and 6.026) versus self-injection was significantly associated with higher current frequency of hospital visits and anxiety or other hurdles related to self-injection. A flexible administration setting was significantly associated with a preference for self-injection versus infusion (OR 0.401) and versus in-hospital injection (OR 0.445). Further, age (< 40 vs. ≥ 60 years) was significantly associated with a preference for self-injection versus in-hospital injection (OR 0.120). Many patients reported no discrepancy between their current and preferred treatment mode (patients receiving infusion, 68.0%; in-hospital injection, 71.2%; and self-injection, 94.0%). However, > 90% of patients responded that they would change their current mode in the future following a recommendation by a medical professional, aging, or a change in RA symptoms.

Conclusions

This web-based survey showed that patient preference for bDMARD treatment mode was significantly associated with age, frequency of hospital visits, flexible administration setting, and anxiety or other hurdles to self-injection. Changes in patient background which affect the preferred treatment mode should be considered in decision-making for RA therapy with bDMARDs.

Trial registration

R000048089 (UMIN-CTR)

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00325-9.

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

BACKGROUND

An 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.

METHODS

We 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.

RESULTS

The 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.

CONCLUSIONS

We 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 REGISTRATION

The current study is not a clinical trial and hence not subject to trial registration.