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

A novel method to monitor rheumatoid arthritis prevalence using hospital and medication databases

BACKGROUND

Most estimates of rheumatoid arthritis (RA) prevalence, including all official figures in Australia and many other countries, are based on self-report. Self-report has been shown to overestimate RA, but the 'gold standard' of reviewing individual medical records is costly, time-consuming and impractical for large-scale research and population monitoring. This study provides an algorithm to estimate RA cases using administrative data that can be adjusted for use in multiple contexts to provide the first approximate RA cohort in Australia that does not rely on self-report.

METHODS

Survey data on self-reported RA and medications from 25 467 respondents of the Australian Longitudinal Study on Women's Health (ALSWH) were linked with data from the national medication reimbursement database, hospital and emergency department (ED) episodes, and Medicare Benefits codes. RA prevalence was calculated for self-reported RA, self-reported RA medications, dispensed RA medications, and hospital/ED RA presentations. Linked data were used to exclude individuals with confounding autoimmune conditions.

RESULTS

Of 25 467 survey respondents, 1367 (5·4%) women self-reported disease. Of the 26 840 women with hospital or ED presentations, 292 (1·1%) received ICD-10 codes for RA. There were 1038 (2·8%) cases by the medication database definition, and 294 cases (1·5%) by the self-reported medication definition. After excluding individuals with other rheumatic conditions, prevalence was 3·9% for self-reported RA, 1·9% based on the medication database definition and 0·5% by self-reported medication definition. This confirms the overestimation of RA based on self-reporting.

CONCLUSIONS

We provide an algorithm for identifying individuals with RA, which could be used for population studies and monitoring RA in Australia and, with adjustments, internationally. Its balance of accuracy and practicality will be useful for health service planning using relatively easily accessible input data.

Evaluation of quantitative bias analysis in epidemiological research: A systematic review from 2010 to mid-2023

OBJECTIVE

We aimed to demonstrate the use of quantitative bias analysis (QBA), which reveals the effects of systematic error, including confounding, misclassification and selection bias, on study results in epidemiological studies published in the period from 2010 to mid-23.

METHOD

The articles identified through a keyword search using Pubmed and Scopus were included in the study. The articles obtained from this search were eliminated according to the exclusion criteria, and the articles in which QBA analysis was applied were included in the detailed evaluation.

RESULTS

It can be said that the application of QBA analysis has gradually increased over the 13-year period. Accordingly, the number of articles in which simple is used as a method in QBA analysis is 9 (9.89%), the number of articles in which the multidimensional approach is used is 10 (10.99%), the number of articles in which the probabilistic approach is used is 60 (65.93%) and the number of articles in which the method is not specified is 12 (13.19%). The number of articles with misclassification bias model is 44 (48.35%), the number of articles with uncontrolled confounder(s) bias model is 32 (35.16%), the number of articles with selection bias model is 7 (7.69%) and the number of articles using more than one bias model is 8 (8.79%). Of the 49 (53.85%) articles in which the bias parameter source was specified, 19 (38.78%) used internal validation, 26 (53.06%) used external validation and 4 (8.16%) used educated guess, data constraints and hypothetical data. Probabilistic approach was used as a bias method in 60 (65.93%) of the articles, and mostly beta (8 [13.33%)], normal (9 [15.00%]) and uniform (8 [13.33%]) distributions were selected.

CONCLUSION

The application of QBA is rare in the literature but is increasing over time. Future researchers should include detailed analyzes such as QBA analysis to obtain inferences with higher evidence value, taking into account systematic errors.

Increased risk of cardiovascular events under the treatments with Janus kinase inhibitors versus biological disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: a retrospective longitudinal population-based study using the Japanese health insurance database

OBJECTIVES

To compare the risk of cardiovascular events among Janus kinase inhibitors (JAKIs), biological disease-modifying antirheumatic drugs (bDMARDs) (tumour necrosis factor inhibitors (TNFIs) and non-TNFIs) and methotrexate (MTX) in Japanese patients with rheumatoid arthritis (RA).

METHODS

Using Japanese claims data, patients with RA were enrolled in this study if they had at least one ICD-10 code (M05 or M06), were new users of JAKIs, bDMARDs or MTX between July 2013 and July 2020 and being 18 years old or older. The incidence rate (IR), IR ratio and adjusted hazard ratio (aHR (95% CI)) of cardiovascular events including venous thromboembolism, arterial thrombosis, acute myocardial infarction and stroke were calculated. A time-dependent Cox regression model adjusted for patient characteristics at baseline was used to calculate aHR.

RESULTS

In 53 448 cases, IRs/1000 patient-years of the overall cardiovascular events were 10.1, 6.8, 5.4, 9.1 and 11.3 under the treatments with JAKIs, bDMARDs, TNFIs, non-TNFIs and MTX, respectively. The adjusted HRs of JAKIs for overall cardiovascular events were 1.7 (1.1 to 2.5) versus TNFIs without MTX and 1.7 (1.1 to 2.7) versus TNFIs with MTX.

CONCLUSIONS

Among patients with RA, individuals using JAKIs had a significantly higher risk of overall cardiovascular events than TNFIs users, which was attributed to the difference in the risk between JAKIs and TNFIs versus MTX. These data should be interpreted with caution because of the limitations associated with the claims database.

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.

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.

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.

Validation studies of Japanese administrative health care data: A scoping review

PURPOSE

Large-scale administrative health care databases are increasingly being utilized for research. However, there has not been much literature that validated administrative data in Japan; a previous review identified six validation studies published between 2011 and 2017. We conducted a literature review of studies that assessed the validity of Japanese administrative health care data.

METHODS

We searched for studies published by March 2022 that compared individual-level administrative data with a reference standard from another data source, as well as studies that validated administrative data using other data within the same database. The eligible studies were also summarized based on characteristics which included data types, settings, reference standard used, numbers of patients, and conditions validated.

RESULTS

There were 36 eligible studies, including 29 that used external reference standard and seven that validated administrative data using other data within the same database. Chart review was the reference standard in 21 studies (range of the numbers of patients, 72-1674; 11 studies conducted in single institutions and nine studies in 2-5 institutions). Five studies used a disease registry as the reference standard. Diagnoses of cardiovascular diseases, cancer, and diabetes were frequently evaluated.

CONCLUSIONS

Validation studies are being conducted at an increasing rate in Japan, although most of them are small scale. Further large-scale comprehensive validation studies are necessary to effectively utilize the databases for research.

Association of Hyperkalemia and Hypokalemia with Patient Characteristics and Clinical Outcomes in Japanese Hemodialysis (HD) Patients

This study aimed to examine the characteristics and clinical outcomes of Japanese hemodialysis patients with dyskalemia. A retrospective study was conducted using a large Japanese hospital group database. Outpatients undergoing thrice-a-week maintenance hemodialysis were stratified into hyperkalemia, hypokalemia, and normokalemia groups based on their pre-dialysis serum potassium (sK) levels during the three-month baseline period. Baseline characteristics of the three groups were described and compared for the following outcomes during follow-up: all-cause mortality, all-cause hospitalization, major adverse cardiovascular events (MACE), cardiac arrest, fatal arrythmia, and death related to arrhythmia. The study included 2846 eligible patients, of which 67% were men with a mean age of 65.65 (SD: 12.63) years. When compared with the normokalemia group (n = 1624, 57.06%), patients in the hypokalemia group (n = 313, 11.00%) were older and suffered from malnutrition, whereas patients in the hyperkalemia group (n = 909, 31.94%) had longer dialysis vintage. The hazard ratios for all-cause mortality and MACE in the hypokalemia group were 1.47 (95% confidence interval [CI], 1.13–1.92) and 1.48 (95% CI, 1.17–1.86), respectively, whereas that of death related to arrhythmia in the hyperkalemia group was 3.11 (95% CI, 1.03–9.33). Thus, dyskalemia in maintenance hemodialysis patients was associated with adverse outcomes, suggesting the importance of optimized sK levels.

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.