Validation Study of Algorithms to Identify Malignant Tumors and Serious Infections in a Japanese Administrative Healthcare Database

Association Between Febuxostat Use and the Incidence of Cardiovascular Events, Mortality, and Kidney Events in Patients With Chronic Kidney Disease Compared to Allopurinol: A Study Using a Japanese Nationwide Database

Background Patients with chronic kidney disease (CKD) were excluded in most trials that investigated the effects of urate-lowering agents, such as febuxostat and allopurinol, in hyperuricemic patients. This exclusion leads to uncertainty regarding the efficacy of febuxostat in patients with CKD. Due to the high prevalence of hyperuricemia in patients with CKD, we aimed to assess the effect of febuxostat on improving patient outcomes concerning cardiovascular events and survival compared with those treated with allopurinol among patients with CKD. Methods We conducted a retrospective cohort study using Japanese nationwide administrative data from Jan 1, 2013, to Sep 30, 2020. Patients aged over 60 years diagnosed with CKD were included in this study if they were prescribed either febuxostat or allopurinol. The primary outcome was the occurrence of cardiovascular events including myocardial infarction, stroke, unstable angina requiring urgent revascularization, and all-cause deaths. We estimated hazard ratios (HR) and 95% CI using a Cox proportional hazard regression model adjusted for comorbidities, medications, and laboratory data. We also assessed defined starting kidney replacement therapy as a secondary endpoint treating death as a competing risk using the Fine & Gray regression model. Results A total of 21,015 patients included those with febuxostat (n=17,796) and those with allopurinol (n=3,219). The association between the type of drug and the occurrence of cardiovascular events did not show a significant difference (0.107 vs. 0.116 events per patient-year; adjusted HR 0.953, 95% CI: 0.854 to 1.062, P=0.381). Similar results were seen for all-cause deaths (0.060 vs. 0.068 events per patient-year; adjusted HR 0.877, 95% CI: 0.760 to 1.012, P=0.073). Regarding the secondary endpoint, the association between the type of drug and the timing of starting kidney replacement therapy did not show a significant difference (0.118 vs. 0.097 events per patient-year; adjusted HR 0.953, 95% CI: 0.854 to 1.062, P=0.425). Conclusion The use of febuxostat was neither associated with a decreased risk of cardiovascular events or deaths nor with the timing of starting kidney replacement therapy compared to the use of allopurinol in patients with CKD.

Incidence of serious infections in the working-age Japanese adult population with rheumatoid arthritis treated with tumor necrosis factor-α inhibitors and interleukin-6 inhibitors: A nationwide retrospective cohort study

AIM

This retrospective cohort study aimed to compare the risk of serious infections in patients with rheumatoid arthritis (RA) treated with tumor necrosis factor-α inhibitors (TNFαi) and interleukin-6 inhibitors (IL-6i), with no prior use of biological disease-modifying antirheumatic drugs (bDMARDs).

METHODS

We employed the nationwide insurance claims database encompassing the years 2005 to 2018 in Japan. The inclusion criteria specified patients who were prescribed any type of bDMARDs, including TNFαi and IL-6i. The following exclusion criteria were applied: missing prescription dates, RA not diagnosed, below 16 years of age, bDMARDs prescribed within 6 months of registration, RA diagnosed post-bDMARDs prescription, and incidence of serious infections within 2 weeks before bDMARDs therapy. We applied stabilized inverse probability weights and utilized a Cox regression model to estimate the risk of serious infections associated with TNFαi and IL-6i.

RESULTS

The cohort of 2493 patients with RA was categorized into a TNFαi group and an IL-6i group of 2018 and 475 participants, respectively. The median follow-up duration (interquartile range) was 347 (147-820) days in the TNFαi group and 369 (149-838) days in the IL-6i group. In the inverse probability-weighted cohort, the incidence rates (95% confidence interval) of serious infections were 2.13 (1.65-2.71) and 3.25 (2.15-4.69) per 100 person-years for the TNFαi and IL-6i groups, respectively. The hazard ratio (95% confidence interval) comparing the TNFαi group to the IL-6i group was 0.66 (0.36-1.20, p = 0.168).

DISCUSSION

The results underscore the lack of evidence to preferentially favor either TNFαi or IL-6i as later-line therapy in the management of bDMARDs-naive RA to mitigate the risk of serious infections.

Fibrates and the risk of cardiovascular outcomes in chronic kidney disease patients

BACKGROUND

The high risk of major adverse cardiovascular events (MACE) in patients with chronic kidney disease (CKD) has been well described. However, the efficacy of fibrates on the risk of MACE in patients with CKD remains unclear.

METHODS

We conducted a nested case-control study using data from a large administrative database that included more than 1.5 million Japanese patients. We defined cases as CKD patients with incidences of MACE and matched them with controls based on age, sex, calendar year of cohort entry and CKD stage. Fibrate exposure timing was categorized as current, recent or past. A conditional logistic regression analysis was used to investigate the association between fibrate use and the risk of MACE.

RESULTS

Our study included 47 490 patients with CKD, with 15 830 MACE identified during a median follow-up of 9.4 months. The numbers of fibrates used during the study period were 556 (3.5%) in the case group and 1109 (3.5%) in the control group. Fibrate use was significantly associated with a decreased risk of MACE [odds ratio (OR) 0.84; 95% confidence interval (CI) 0.75-0.94], particularly for current (OR 0.81; 95% CI 0.68-0.97) and recent use (OR 0.65; 95% CI 0.48-0.90). Regarding the class effect of fibrates, pemafibrate use, but not bezafibrate or fenofibrate use, was significantly associated with a decreased risk of MACE (OR 0.73; 95% CI 0.528-0.997).

CONCLUSION

Recent and current fibrate use, especially pemafibrate use, was associated with a reduced risk of MACE in patients with CKD. This suggests the potential benefits of continuous fibrate therapy and the possible superiority of pemafibrate over other fibrates. However, further investigations in different populations are required to confirm the generalizability of these findings.

Association of Antipsychotic Drugs with the Risk of Recurrent Venous Thromboembolism: A Retrospective Study of Data from a Japanese Inpatient Database

BACKGROUND

Approximately a decade has passed since the addition of venous thromboembolism to the list of significant adverse reactions of antipsychotic drugs. However, only a few studies have investigated the relationship between antipsychotic use and venous thromboembolism in the Japanese population.

PURPOSE

We aimed to evaluate the risk of recurrent venous thromboembolism in users of antipsychotic drugs and update the evidence on venous thromboembolism in the Japanese population.

METHODS

A cross-sectional retrospective analysis of data from a large Japanese claims database, managed by Medical Data Vision Co. Ltd., was conducted. Adult patients who experienced venous thromboembolism between October 2014 and September 2018 in acute care hospitals were identified. The risk of recurrent venous thromboembolism was evaluated with logistic regression using demographic variables. The data of patients using antipsychotic drugs within specific therapeutic classes were also evaluated.

RESULTS

We included 8960 patients (mean age, 69 years; 59.2% female). Recurrent venous thromboembolism was observed in 686 patients (7.7%). The risk of recurrent venous thromboembolism was significantly higher in younger patients [< 65 years: reference; 65-74 years: odds ratio (OR) 0.81, 95% confidence interval (CI) 0.66-0.99, p = 0.04; ≥ 75 years: OR 0.77, 95% CI 0.64-0.94, p = 0.01], those with history of surgery (OR 1.39, 95% CI 1.18-1.65, p = 0.01), and anticoagulant users (OR 2.25, 95% CI 1.46-3.48, p = 0.01) and was significantly lower in the presence of comorbidities (OR 0.68, 95% CI 0.58-0.81, p< 0.01) and fractures (OR 0.49, 95% CI 0.26-0.94, p = 0.03). Long-term antipsychotic drug prescriptions (> 14 days) were associated with a higher risk of venous thromboembolism than short-term prescriptions (≤ 14 days) (OR 1.56, 95% CI 1.04-2.34, p = 0.03).

CONCLUSIONS

In patients with a history of venous thromboembolism, particular attention should be paid to recurrence in younger patients. If antipsychotic drugs are prescribed for > 14 days to patients with a history of venous thromboembolism, they should be administered carefully, guided by reported findings. Further evaluations using different databases or populations are required to generalize the findings of this study.

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 study of case-identifying algorithms for severe hypoglycemia using hospital administrative data in Japan

OBJECTIVE

The purpose of this study was to evaluate the performance of algorithms for identifying cases of severe hypoglycemia in Japanese hospital administrative data.

METHODS

This was a multicenter, retrospective, observational study conducted at 3 acute-care hospitals in Japan. The study population included patients aged ≥18 years with diabetes who had an outpatient visit or hospital admission for possible hypoglycemia. Possible cases of severe hypoglycemia were identified using health insurance claims data and Diagnosis Procedure Combination data. Sixty-one algorithms using combinations of diagnostic codes and prescription of high concentration (≥20% mass/volume) injectable glucose were used to define severe hypoglycemia. Independent manual chart reviews by 2 physicians at each hospital were used as the reference standard. Algorithm validity was evaluated using standard performance metrics.

RESULTS

In total, 336 possible cases of severe hypoglycemia were identified, and 260 were consecutively sampled for validation. The best performing algorithms included 6 algorithms that had sensitivity ≥0.75, and 6 algorithms that had positive predictive values ≥0.75 with sensitivity ≥0.30. The best-performing algorithm with sensitivity ≥0.75 included any diagnoses for possible hypoglycemia or prescription of high-concentration glucose but excluded suspected diagnoses (sensitivity: 0.986 [95% confidence interval 0.959-1.013]; positive predictive value: 0.345 [0.280-0.410]). Restricting the algorithm definition to those with both a diagnosis of possible hypoglycemia and a prescription of high-concentration glucose improved the performance of the algorithm to correctly classify cases as severe hypoglycemia but lowered sensitivity (sensitivity: 0.375 [0.263-0.487]; positive predictive value: 0.771 [0.632-0.911]).

CONCLUSION

The case-identifying algorithms in this study showed moderate positive predictive value and sensitivity for identification of severe hypoglycemia in Japanese healthcare data and can be employed by future pharmacoepidemiological studies using Japanese hospital administrative databases.

Risk of a second cancer and infection in patients with indolent B-cell lymphoma exposed to first-line bendamustine plus rituximab: A retrospective analysis of an administrative claims database

Bendamustine has a potent immunosuppressive effect because it causes T-cell lymphopenia, which might lead to a second primary malignancy (SPM) and would increase the risk of infection. Using the Medical Data Vision administrative claims database, we compared the cumulative incidence of SPM, infections within 6 months, and overall survival (OS) among untreated patients with indolent B-cell lymphomas (iBCL) who received rituximab-based chemotherapy between 2009 and 2020. Patients with grade 3b follicular lymphoma or a previous history of malignancy were excluded. Eligible 5234 patients were assigned to three cohorts: rituximab monotherapy (N = 780), RCHOP/RCVP/RTHPCOP (doxorubicin replaced with pirarubicin) (N = 2298), or bendamustine/rituximab (BR) (N = 2156). There were 589 recorded SPMs, of which myelodysplastic syndromes were the most common (1.7%). The cumulative incidence of SPM was significantly higher in patients treated with BR than in those treated with rituximab monotherapy (p < 0.01) or RCHOP/RCVP/RTHPCOP (p < 0.0001): the 5-year cumulative incidence function was 18.1%, 12.5%, and 12.9%, respectively. In the Fine-Gray subdistribution hazards model, BR showed a significantly higher cumulative incidence of SPM than RCHOP/RCVP/RTHPCOP (subhazard ratio, 1.33; 95% confidence interval [CI], 1.10-1.61). Furthermore, in sensitivity analysis, a nested case-control study using an entire cohort showed consistent results: the SPM odds ratios (95% CI) of first-line bendamustine, bendamustine after first-line, and any-line bendamustine were 1.43 (1.14-1.78), 1.26 (0.96-1.64), and 1.33 (1.09-1.62), respectively. Regarding infections, adjusted odds ratios (95% CI) of BR compared to RCHOP/RCVP/RTHPCOP were as follows: cytomegalovirus infection, 13.7 (4.88-38.4); bacterial pneumonia, 0.63 (0.50-0.78); and pneumocystis pneumonia, 0.24 (0.11-0.53). There was no significant difference in OS between RCHOP/RCVP/RTHPCOP and BR in patients with follicular, mantle cell, marginal zone, or lymphoplasmacytic lymphomas. In conclusion, treatment strategies that consider the risk of SPM and infections after chemotherapy are warranted in patients with iBCL.

Risk of infection from glucocorticoid and methotrexate interaction in patients with rheumatoid arthritis using biologics: A retrospective cohort study

AIMS

This retrospective cohort study aimed to evaluate the effect of the interaction between methotrexate and glucocorticoids on the risk of developing bacterial infections in patients with rheumatoid arthritis (RA) using biological disease-modifying antirheumatic drugs (bDMARDs).

METHODS

We used the 2005-2018 JMDC claims database, a nationwide claims database in Japan. From the database of 7 175 048 patients, study patients were obtained by applying the following exclusion criteria: no use of bDMARDs; without information on the date of prescription; without RA as a disease; other than the new users of bDMARDs; and age <18 years. The exposures were glucocorticoids and methotrexate, and the outcome was bacterial infection. The interaction effects were examined using multivariate Cox regression analysis. Bacterial infections were identified according to antibiotic prescription and International Statistical Classification of Diseases and Related Health Problems, 10th revision codes.

RESULTS

A total of 2837 RA patients were identified, with a median age of 50 years. The incidence of infection was 16.8% (95% confidence interval: 15.5-18.3). The interaction term for the doses of glucocorticoids and methotrexate was significant. Additionally, a higher dose of glucocorticoid was a significant risk factor for developing bacterial infections on the side of high doses of methotrexate. The incidence of bacterial infections tended to increase significantly with increasing methotrexate doses coprescribed with glucocorticoids ≥5 mg or glucocorticoid doses coprescribed with methotrexate ≥8 mg.

CONCLUSION

Our results indicate a potential association between methotrexate dose and bacterial infections during bDMARDs administration with glucocorticoids in patients with RA.

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.

Validation of algorithms to identify colorectal cancer patients from administrative claims data of a Japanese hospital

BACKGROUND

Administrative claims data are a valuable source for clinical studies; however, the use of validated algorithms to identify patients is essential to minimize bias. We evaluated the validity of diagnostic coding algorithms for identifying patients with colorectal cancer from a hospital's administrative claims data.

METHODS

This validation study used administrative claims data from a Japanese university hospital between April 2017 and March 2019. We developed diagnostic coding algorithms, basically based on the International Classification of Disease (ICD) 10th codes of C18-20 and Japanese disease codes, to identify patients with colorectal cancer. For random samples of patients identified using our algorithms, case ascertainment was performed using chart review as the gold standard. The positive predictive value (PPV) was calculated to evaluate the accuracy of the algorithms.

RESULTS

Of 249 random samples of patients identified as having colorectal cancer by our coding algorithms, 215 were confirmed cases, yielding a PPV of 86.3% (95% confidence interval [CI], 81.5-90.1%). When the diagnostic codes were restricted to site-specific (right colon, left colon, transverse colon, or rectum) cancer codes, 94 of the 100 random samples were true cases of colorectal cancer. Consequently, the PPV increased to 94.0% (95% CI, 87.2-97.4%).

CONCLUSION

Our diagnostic coding algorithms based on ICD-10 codes and Japanese disease codes were highly accurate in detecting patients with colorectal cancer from this hospital's claims data. The exclusive use of site-specific cancer codes further improved the PPV from 86.3 to 94.0%, suggesting their desirability in identifying these patients more precisely.

Prevalence and changes of low-value care at acute care hospitals: a multicentre observational study in Japan

OBJECTIVES

We aimed to examine the use and factors associated with the provision of low-value care in Japan.

DESIGN

A multicentre observational study.

SETTING

Routinely collected claims data that include all inpatient and outpatient visits in 242 large acute care hospitals (accounting for approximately 11% of all acute hospitalisations in Japan).

PARTICIPANTS

345 564 patients (median age (IQR): 62 (40-75) years; 182 938 (52.9%) women) seeking care at least once in the hospitals in the fiscal year 2019.

PRIMARY AND SECONDARY OUTCOME MEASURES

We identified 33 low-value services, as defined by clinical evidence, and developed two versions of claims-based measures of low-value services with different sensitivity and specificity (broader and narrower definitions). We examined the number of low-value services, the proportion of patients receiving these services and the proportion of total healthcare spending incurred by these services in 2019. We also evaluated the 2015-2019 trends in the number of low-value services.

RESULTS

Services identified by broader low-value care definition occurred in 7.5% of patients and accounted for 0.5% of overall annual healthcare spending. Services identified by narrower low-value care definition occurred in 4.9% of patients and constituted 0.2% of overall annual healthcare spending. Overall, there was no clear trend in the prevalence of low-value services between 2015 and 2019. When focusing on each of the 17 services accounting for more than 99% of all low-value services identified (narrower definition), 6 showed decreasing trends from 2015 to 2019, while 4 showed increasing trends. Hospital size and patients' age, sex and comorbidities were associated with the probability of receiving low-value service.

CONCLUSIONS

A substantial number of patients received low-value care in Japan. Several low-value services with high frequency, especially with increasing trends, require further investigation and policy interventions for better resource allocation.

Validity of claims data for identifying cancer incidence in the Japan public health center-based prospective study for the next generation

PURPOSE

This study determined the validity of claims-based definitions for identifying the incidence of total and site-specific cancers in a population-based cohort study.

METHODS

Claims data were obtained for 21 946 participants aged 40-74 years enrolled in the Japan Public Health Center-based Prospective Study for the Next Generation. We defined total and site-specific cancer incidence using combinations of codes from claims data, including diagnosis and procedure codes for cancer therapy. Data from the cancer registry were used as the gold standard to evaluate validity.

RESULTS

Among 21 946 participants, 454 total, 89 stomach, 67 colorectal, 51 lung, 39 breast and 99 prostate invasive cancer cases were newly diagnosed in the cancer registry. For invasive cancer, the sensitivity and specificity of the definition that combined codes for diagnosis and procedures for cancer therapy were 87.0% and 99.4% for total, 88.8% and 99.9% for stomach, 80.6% and 99.9% for colorectal, 86.3% and 99.9% for lung, 100% and 99.9% for breast and 91.9% and 99.9% for prostate cancer, respectively. Furthermore, for invasive and/or in situ cancer, the sensitivity and specificity of the definition were 84.5% and 99.5% for total, 66.7% and 99.9% for colorectal and 100% and 99.9% for breast cancer.

CONCLUSIONS

Our findings suggest that claims-based definitions using diagnosis and procedure codes generally have high validity for total, stomach, lung, breast and prostate cancer incidence, but may underestimate colorectal cancer incidence.