Claims-based definition of death in Japanese claims database: validity and implications

Anesthesia practice for Cesarean delivery in Japan: a retrospective cohort study

PURPOSE

General anesthesia for Cesarean delivery affects maternal and neonatal outcomes. We aimed to evaluate temporal trends in anesthesia management for Cesarean deliveries over 16 years and analyze interinstitutional variations in general anesthesia use in Japan.

METHODS

In this retrospective cohort study, we obtained patient data from the nationwide health insurance claims database containing data for ten million individuals. We included patients who underwent Cesarean delivery between 1 January 2005 and 31 August 2021. The primary outcome was the use of general anesthesia. We evaluated institutional variations in general anesthesia use in medical facilities using two-level hierarchical logistic regression analyses with median odds ratios and intraclass correlation coefficients.

RESULTS

The cohort included 86,793 patients who underwent 102,617 Cesarean deliveries at 2,496 institutions. General anesthesia was used in 3.7% (95% confidence interval [CI], 3.6 to 3.9) of all Cesarean deliveries. The temporal trend in the use of general anesthesia decreased gradually from 10.8% in 2005 to 2.9% in 2021 (P for trend < 0.001). The adjusted median odds ratio for medical facilities was 6.1 (95% CI, 5.9 to 6.7), and the intraclass correlation coefficient was 0.52 (95% CI, 0.51 to 0.55).

CONCLUSION

Although the rate of general anesthesia use for Cesarean delivery in Japan decreased gradually from 2005 to 2021, general anesthesia was used in 3.7% of all Cesarean deliveries. The use of general anesthesia varied significantly across institutions, and 52% of the overall variations in general anesthesia practice can be explained by differences between facilities.

Association between number of medications and hip fractures in Japanese elderly using conditional logistic LASSO regression

To examine the association between hip fracture and associated factors, including polypharmacy, and develop an optimal predictive model, we conducted a population-based matched case-control study using the health insurance claims data on hip fracture among Japanese patients. We included 34,717 hospitalized Japanese patients aged ≥ 65 years with hip fracture and 34,717 age- and sex- matched controls who were matched 1:1. This study included 69,434 participants. Overall, 16 variable comorbidities and 60 variable concomitant medications were used as explanatory variables. The participants were added to early elderly and late elderly categories for further analysis. The odds ratio of hip fracture increased with the number of medications only in the early elderly. AUC was highest for early elderly (AUC, 0.74, 95% CI 0.72-0.76). Use of anti-Parkinson's drugs had the largest coefficient and was the most influential variable in many categories. This study confirmed the association between risk factors, including polypharmacy and hip fracture. The risk of hip fracture increased with an increase in medication number taken by the early elderly and showed good predictive accuracy, whereas there was no such association in the late elderly. Therefore, the early elderly in Japan should be an active target population for hip fracture prevention.

Statin persistence and adherence among older initiators: A nationwide cohort study using the national health insurance claims database in Japan

PURPOSE

This study clarifies the reality of persistence and adherence to statins in older Japanese people who initiated statin use and compares it between primary and secondary prevention cohorts.

METHODS

The nationwide study using the national claims database targeted statin initiators aged ≥55 years from FY2014 to FY2017 in Japan. Persistence and adherence to statins were analyzed overall and according to subgroups based on sex, age stratum, and prevention cohorts. Permissible gap of median days that statins were supplied per prescription to an individual was employed. Persistence rates were estimated as Kaplan-Meier estimates. Poor adherence during persistence was evaluated and defined as <0.8 of the proportion of days covered.

RESULTS

Of 3 675 949 initiators, approximately 80% initiated statin use with strong variants. The persistence rate at 1 year was 0.61. Poor adherence to statins during persistence was 8.0% in all patients and this value gradually improved with increasing age. Persistence rate and adherence were lower for the primary prevention cohort than for the secondary prevention cohort, and a notable sex difference was observed for the secondary prevention cohort, which was lower in females but was almost never and slightly observed in the primary prevention cohorts without and with high-risk factors, respectively.

CONCLUSIONS

Many statin initiators discontinued statins shortly following statin initiation but adherence while on statin therapy was good. Attentively watching older patients not to discontinue statins and listening to their reasons for discontinuation are required, especially for initiators in primary prevention and females in secondary prevention.

Studies of Health Insurance Claims Data in Japan: A Scoping Review

BACKGROUND

Health insurance claims data are used in various research fields; however, an overview on how they are used in healthcare research is scarce in Japan. Therefore, we conducted a scoping review to systematically map the relevant studies using Japanese claims data.

METHODS

MEDLINE, EMBASE, and Ichushi-Web were searched up to April 2021 for studies using Japanese healthcare claims data. We abstracted the data on study characteristics and summarized target diseases and research themes by the types of claims database. Moreover, we described the results of studies that aimed to compare health insurance claims data with other data sources narratively.

RESULTS

A total of 1,493 studies were included. Overall, the most common disease classifications were "Diseases of the circulatory system" (18.8%, n = 281), "Endocrine, nutritional, and metabolic diseases" (11.5%, n = 171; mostly diabetes), and "Neoplasms" (10.9%, n = 162), and the most common research themes were "medical treatment status" (30.0%, n = 448), "intervention effect" (29.9%, n = 447), and "clinical epidemiology, course of diseases" (27.9%, n = 417). Frequent diseases and themes varied by type of claims databases. A total of 19 studies aimed to assess the validity of the claims-based definition, and 21 aimed to compare the results of claims data with other data sources. Most studies that assessed the validity of claims data compared to medical records were hospital-based, with a small number of institutions.

CONCLUSIONS

Claims data are used in various research areas and will increasingly provide important evidence for healthcare policy in Japan. It is important to use previous claims database studies and share information on methodology among researchers, including validation studies, while informing policymakers about the applicability of claims data for healthcare planning and management.

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.

Prevalence of multimorbidity and its associations with hospitalisation or death in Japan 2014-2019: a retrospective cohort study using nationwide medical claims data in the middle-aged generation

OBJECTIVE

To describe the prevalence of multimorbidity and its associations with clinical outcomes across age groups.

DESIGN

Retrospective cohort study using nationwide medical claims data.

SETTING

Carried out in Japan between April 2014 and March 2019.

PARTICIPANTS

N=246 671 Japanese individuals aged 20-74 enrolled in the health insurance were included into the baseline data set for fiscal year (FY) 2014. Of those, N=181 959 individuals were included into the cohort data set spanning FY2014-FY2018.

EXPOSURES

Multimorbidity was defined as having ≥2 of 15 chronic conditions according to the International Classification of Diseases 10th Revision codes of the Charlson Comorbidity Index.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome: the standardised prevalence of multimorbidity across age groups was evaluated using data from FY2014 and extrapolated to the Japanese total population.

SECONDARY OUTCOME

hospitalisation or death events were traced by month using medical claims data and insurer enrolment data. Associations between multimorbidity and 5-year hospitalisation and/or death events across age groups were analysed using a Cox regression model.

RESULTS

The standardised prevalence rate of multimorbidity in the nationwide Japanese total population was estimated to 26.1%. The prevalence rate with age was increased, approximately 5% (ages 20-29), 10% (30-39), 20% (40-49), 30% (50-59), 50% (60-69) and 60% (70-74). Compared with individuals aged 20-39 without multimorbidity, those with multimorbidity had a higher incidence of clinical events in any age group (HR=2.43 (95% CI 2.30 to 2.56) in ages 20-39, HR=2.55 (95% CI 2.47 to 2.63) in ages 40-59 and HR=3.41 (95% CI 3.23 to 3.53) in ages ≥60). The difference in the incidence of clinical events between multimorbidity and no multimorbidity was larger than that between age groups.

CONCLUSIONS

Multimorbidity is already prevalent in the middle-aged generation and is associated with poor clinical outcomes. These findings underscore the significance of multimorbidity and highlight the urgent need for preventive intervention at the public healthcare level.

The prevalence of end-of-life chemotherapy and targeted therapy in Japan, assessed using a health claims database

PURPOSE

This study aimed to investigate the current status of end-of-life chemotherapy and targeted therapy and explore the aggressiveness of end-of-life care in Japan using the DeSC database, a large administrative claims database.

METHODS

We identified fatal cases of at least one cancer-related diagnosis between April 2015 and November 2020. Patients prescribed at least one anticancer drug were analyzed, and chemotherapy regimens were categorized based on the combination of concomitant anticancer drugs prescribed.

RESULTS

Among 1,095,713 individuals enrolled in the National Health Insurance database, 7,300 deaths with cancer-related diagnosis were identified. Of these, 4,010 cases were identified in which at least one anticancer drug was prescribed, and 11.6% of 7,300 death had been prescribed anticancer drugs in their last 30 days of life. The most commonly used regimen was S-1 (tegafur, gimeracil, and oteracil potassium combination) monotherapy, followed by nivolumab monotherapy and nab-paclitaxel plus gemcitabine. Immune checkpoint inhibitor monotherapy was more likely prescribed to patients whose last chemotherapy dose was in the last 30 days of life (p = 0.0066, chi-squared test).

CONCLUSIONS

This study provides insights into the current status of end-of-life chemotherapy and targeted therapy in Japan, using a large administrative claims database. The results of this study will inform future research on end-of-life chemotherapy and targeted therapy, and help develop strategies to improve the quality of life of patients with advanced cancer.

A Review of Studies Using Japanese Nationwide Administrative Claims Databases

BACKGROUND

Administrative claims databases are increasingly being used worldwide for research purposes. We reviewed original published articles that used one of the four nationwide administrative claims databases in Japan: the National Database of Health Insurance Claims and Specific Health Checkups (NDB), NDB Open Data, the JMDC Claims Database, and the Diagnosis Procedure Combination (DPC) database.

METHODS

Studies published from January 2010 to July 2022 using the JMDC and DPC databases, and from January 2013 to July 2022 using the NDB and NDB Open Data were identified using PubMed. The number of original articles was divided into 19 fields. The annual growth rate of the number of studies was calculated using the four databases.

RESULTS

Overall, 1047 studies were included (95 for the NDB, 31 for the NDB Open Data, 222 for the JMDC database, and 699 for the DPC databases). Studies using one of these four databases increased from around 2010, and the average annual growth rate was approximately 41% from 2010 to 2021. DPC database studies had a higher proportion of articles on surgery (19.2%), urology (3.0%), neurosurgery (6.2%), anesthesiology (1.9%), and emergency medicine (14.0%), whereas the NDB and JMDC data had higher proportions of those regarding internal medicine.

CONCLUSIONS

Since 2010, these four databases have increasingly attracted attention, and the number of studies using them has grown rapidly. Our review suggests that each has unique features, and researchers should understand the database characteristics to operate their studies.

Validation study on definition of cause of death in Japanese claims data

Identifying the cause of death is important for the study of end-of-life patients using claims data in Japan. However, the validity of how cause of death is identified using claims data remains unknown. Therefore, this study aimed to verify the validity of the method used to identify the cause of death based on Japanese claims data. Our study population included patients who died at two institutions between January 1, 2018 and December 31, 2019. Claims data consisted of medical data and Diagnosis Procedure Combination (DPC) data, and five definitions developed from disease classification in each dataset were compared with death certificates. Nine causes of death, including cancer, were included in the study. The definition with the highest positive predictive values (PPVs) and sensitivities in this study was the combination of "main disease" in both medical and DPC data. For cancer, these definitions had PPVs and sensitivities of > 90%. For heart disease, these definitions had PPVs of > 50% and sensitivities of > 70%. For cerebrovascular disease, these definitions had PPVs of > 80% and sensitivities of> 70%. For other causes of death, PPVs and sensitivities were < 50% for most definitions. Based on these results, we recommend definitions with a combination of "main disease" in both medical and DPC data for cancer and cerebrovascular disease. However, a clear argument cannot be made for other causes of death because of the small sample size. Therefore, the results of this study can be used with confidence for cancer and cerebrovascular disease but should be used with caution for other causes of death.

Cardiovascular risk of urate-lowering drugs: A study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan

In the present study, we aimed to investigate the association between urate-lowering drugs and cardiovascular events, primarily focusing on the risk of febuxostat and topiroxostat when compared with allopurinol in Japan. We conducted an observational study with a cohort design using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, including new urate-lowering drugs users between August 1, 2010, and March 31, 2018. Exposure and control groups were defined based on the first prescription of urate-lowering drugs as follows: febuxostat or topiroxostat for exposure groups, allopurinol for the control group, and benzbromarone for the secondary control group. The primary outcome was cardiovascular events, defined as a composite of acute coronary syndrome, cerebral infarction, and cerebral hemorrhage. Hazard ratios were estimated using a Cox proportional hazards model. The number of patients in each exposure and control group was 1,357,671 in the febuxostat group, 83,683 in the topiroxostat group, 1,273,211 in the allopurinol group, and 258,786 in the benzbromarone group. The adjusted hazard ratios for the cardiovascular risk were 0.97 (95% confidence interval [CI]: 0.95-0.98) for febuxostat and 0.84 (95% CI: 0.78-0.90) for topiroxostat groups. The benzbromarone group exhibited similar results. No increased cardiovascular risk was observed with febuxostat or topiroxostat when compared with allopurinol in patients with hyperuricemia in Japan. These results provide real-world evidence regarding the cardiovascular risk associated with urate-lowering drugs, indicating that no additional safety-related regulatory actions are warranted in Japan.

Accuracy of algorithms to identify patients with a diagnosis of major cancers and cancer-related adverse events in an administrative database: a validation study in an acute care hospital in Japan

OBJECTIVES

Validation studies in oncology are limited in Japan. This study was conducted to evaluate the accuracy of diagnosis and adverse event (AE) definitions for specific cancers in a Japanese health administrative real-world database (RWD).

DESIGN AND SETTING

Retrospective observational validation study to assess the diagnostic accuracy of electronic medical records (EMRs) and claim coding regarding oncology diagnosis and AEs based on medical record review in the RWD. The sensitivity and positive predictive value (PPV) with 95% CIs were calculated.

PARTICIPANTS

The validation cohort included patients with lung (n=2257), breast (n=1121), colorectal (n=1773), ovarian (n=216) and bladder (n=575) cancer who visited the hospital between January 2014 and December 2018, and those with prostate cancer (n=3491) visiting between January 2009 and December 2018, who were identified using EMRs.

OUTCOMES

Key outcomes included primary diagnosis, deaths and AEs.

RESULTS

For primary diagnosis, sensitivity and PPV for the respective cancers were as follows: lung, 100.0% (96.6 to 100.0) and 81.0% (74.9 to 86.2); breast, 100.0% (96.3 to 100.0) and 74.0% (67.3 to 79.9); colorectal, 100.0% (96.6 to 100.0) and 80.5% (74.3 to 85.8); ovarian, 89.8% (77.8 to 96.6) and 75.9% (62.8 to 86.1); bladder, 78.6% (63.2 to 89.7) and 67.3% (52.5 to 0.1); prostate, 100.0% (93.2 to 100.0) and 79.0% (69.7 to 86.5). Sensitivity and PPV for death were as follows: lung, 97.0% (84.2 to 99.9) and 100.0% (84.2 to 100.0); breast, 100.0% (1.3 to 100.0) and 100.0% (1.3 to 100.0); colorectal, 100.0% (28.4 to 100.0) and 100.0% (28.4 to 100.0); ovarian, 100.0% (35.9 to 100.0) and 100.0% (35.9 to 100.0); bladder, 100.0% (9.4-100.0) and 100.0% (9.4 to 100.0); prostate, 75.0% (19.4 to 99.4) and 100.0% (19.4 to 100.0). Overall, PPV tended to be low, with the definition based on International Classification of Diseases, 10th revision alone for AEs.

CONCLUSION

Diagnostic accuracy was not so high, and therefore needs to be further investigated.

TRIAL REGISTRATION NUMBER

University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000039345).

Large-scale evidence generation and evaluation across a network of databases for type 2 diabetes mellitus (LEGEND-T2DM): a protocol for a series of multinational, real-world comparative cardiovascular effectiveness and safety studies

INTRODUCTION

Therapeutic options for type 2 diabetes mellitus (T2DM) have expanded over the last decade with the emergence of cardioprotective novel agents, but without such data for older drugs, leaving a critical gap in our understanding of the relative effects of T2DM agents on cardiovascular risk.

METHODS AND ANALYSIS

The large-scale evidence generations across a network of databases for T2DM (LEGEND-T2DM) initiative is a series of systematic, large-scale, multinational, real-world comparative cardiovascular effectiveness and safety studies of all four major second-line anti-hyperglycaemic agents, including sodium-glucose co-transporter-2 inhibitor, glucagon-like peptide-1 receptor agonist, dipeptidyl peptidase-4 inhibitor and sulfonylureas. LEGEND-T2DM will leverage the Observational Health Data Sciences and Informatics (OHDSI) community that provides access to a global network of administrative claims and electronic health record data sources, representing 190 million patients in the USA and about 50 million internationally. LEGEND-T2DM will identify all adult, patients with T2DM who newly initiate a traditionally second-line T2DM agent. Using an active comparator, new-user cohort design, LEGEND-T2DM will execute all pairwise class-versus-class and drug-versus-drug comparisons in each data source, producing extensive study diagnostics that assess reliability and generalisability through cohort balance and equipoise to examine the relative risk of cardiovascular and safety outcomes. The primary cardiovascular outcomes include a composite of major adverse cardiovascular events and a series of safety outcomes. The study will pursue data-driven, large-scale propensity adjustment for measured confounding, a large set of negative control outcome experiments to address unmeasured and systematic bias.

ETHICS AND DISSEMINATION

The study ensures data safety through a federated analytic approach and follows research best practices, including prespecification and full disclosure of results. LEGEND-T2DM is dedicated to open science and transparency and will publicly share all analytic code from reproducible cohort definitions through turn-key software, enabling other research groups to leverage our methods, data and results to verify and extend our findings.

Hematopoietic Stem-Cell Transplant Utilization in Relapsed/Refractory Hodgkin Lymphoma: A Population-Level Analysis of Statewide Claims Data

PURPOSE

Although hematologic malignancies affect adults of all ages, few data exist on the real-world patterns of care for patients younger than 65 years in the United States. Understanding patterns of care from diagnosis through relapsed disease may provide insight about care across community and academic centers. We used a large statewide claims database to describe the path of Hodgkin lymphoma (HL) treatment among adults age < 65 years at diagnosis.

METHODS

We defined a cohort of commercially insured patients with HL who underwent hematopoietic stem-cell transplantation (HSCT) from 2009 to 2013 in the Massachusetts All-Payer Claims Database (APCD). The primary goals of our study were to accurately identify patients and their treatment patterns who had relapsed/refractory HL and underwent HSCT. We also characterized time to treatment failure and overall survival.

RESULTS

A total of 7,613 patients had International Classification of Diseases, Ninth Revision, diagnostic codes for HL. From our algorithm, we identified 117 patients as part of the final cohort who underwent autologous and/or allogeneic HSCT. Median age was 39.0 years and 50.4% were female. Initial therapy was identified for 68 of the 117 patients (58.1%). Most (> 74.4%) of the identified transplants were autologous, and 19 patients (16.2%) underwent allogeneic transplant, with or without prior autologous transplant. Of the 68 patients with initial therapy data, the median time to HSCT after completion of initial treatment was 223.5 days (Q1 = 151.5, Q3 = 414.5).

CONCLUSION

We used the Massachusetts APCD to create a cohort of patients age < 65 years with relapsed/refractory HL. Our findings support the use of APCD for the large-scale analysis of patient characteristics, treatment patterns, and outcomes for young adult patients with hematologic malignancies.

Effectiveness and Safety of Reduced and Standard Daily Doses of Direct Oral Anticoagulants in Patients with Nonvalvular Atrial Fibrillation: A Cohort Study Using National Database Representing the Japanese Population

Purpose

To compare the effectiveness and safety of reduced or standard daily doses of direct oral anticoagulants (DOACs) with warfarin in Japanese patients with nonvalvular atrial fibrillation (NVAF). We used post-hoc analyses to identify patient groups that could benefit from reduced-dose DOACs.

Patients and Methods

Using the National Database of Health Insurance Claims and Specific Health Checkups of Japan, we identified 944,776 patients with NVAF who had started an oral anticoagulant after at least one year of non-use between April 2011 and March 2016. We matched patients taking any, reduced, or standard doses of DOACs 1:1 with those taking warfarin. We measured treatment effectiveness based on admission due to stroke or systemic embolism (S/SE) and safety based on admission due to any bleeding (defined as major bleeding, MB). We compared both outcomes between DOACs and warfarin using the Cox proportional hazards model. We used post-hoc analysis to match patients receiving reduced-dose DOACs to those receiving standard-dose DOACs and compared treatment effectiveness and safety.

Results

More than half of patients receiving DOACs used a reduced dose. The occurrences of S/SE and MB in patients receiving any, reduced, or standard doses of DOACs were equal to or lower than those receiving warfarin. In the post-hoc analysis, the risk of S/SE and MB was similar between reduced and standard doses of DOACs except for those with a history of cerebral infarction and CHA2DS2-VASc score ≥3, where the risk of S/SE was lower for reduced doses of any and individual DOACs.

Conclusion

Findings from the current study are consistent with recent Asian and global studies but different from most studies conducted in North America and Europe, where patients receiving a reduced dose of DOACs had an increased risk of S/SE. Future studies should test the reproducibility of results from the current study.

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

BACKGROUND

This retrospective observational study validated case-finding algorithms for malignant tumors and serious infections in a Japanese administrative healthcare database.

METHODS

Random samples of possible cases of each disease (January 2015-January 2018) from two hospitals participating in the Medical Data Vision Co., Ltd. (MDV) database were identified using combinations of ICD-10 diagnostic codes and other procedural/billing codes. For each disease, two physicians identified true cases among the random samples of possible cases by medical record review; a third physician made the final decision in cases where the two physicians disagreed. The accuracy of case-finding algorithms was assessed using positive predictive value (PPV) and sensitivity.

RESULTS

There were 2,940 possible cases of malignant tumor; 180 were randomly selected and 108 were identified as true cases after medical record review. One case-finding algorithm gave a high PPV (64.1%) without substantial loss in sensitivity (90.7%) and included ICD-10 codes for malignancy and photographing/imaging. There were 3,559 possible cases of serious infection; 200 were randomly selected and 167 were identified as true cases after medical record review. Two case-finding algorithms gave a high PPV (85.6%) with no loss in sensitivity (100%). Both case-finding algorithms included the relevant diagnostic code and immunological infection test/other related test and, of these, one also included pathological diagnosis within 1 month of hospitalization.

CONCLUSIONS

The case-finding algorithms in this study showed good PPV and sensitivity for identification of cases of malignant tumors and serious infections from an administrative healthcare database in Japan.

Key Characteristics of Database Studies on Drug Effectiveness in the Postmarketing Stage: A Systematic Review

BACKGROUND

In recent years, real-world data (RWD) have been actively used in the field of pharmaceutical research. Database (DB) study, one of the observational studies using RWD, is a comprehensive, continuous, and rapid research method that plays an important role in the postmarketing stage of drugs, although the interpretation of the results may be limited. DB studies are often focused on drug safety, and previous research reviewing DB studies on drug effectiveness across different disease areas have been limited.

OBJECTIVE

The objective of this review was to reveal the current status of DB studies on drug effectiveness in various therapeutic areas and to provide information that allows researchers to consider conducting appropriate DB studies on drug effectiveness in the postmarketing stage.

METHODS

For this systematic review, we searched Embase and MEDLINE for DB studies on drug effectiveness published between 1 January 2018 and 31 December 2019. We reviewed the title, abstract, and methods to identify studies on drug effectiveness using medical information DBs, and excluded non-medical studies, studies on non-drug, and studies on drug safety, actual use, or cost outcomes that did not include any effectiveness outcomes. The name and type of the DB (administrative claims DB, clinical DB, pharmacy DB, and DB linkage), study design, comparison group, type of outcome, and presence or absence of reference to the outcome definition were extracted and summarized according to disease areas.

RESULTS

We obtained 225 articles on DB studies on drug effectiveness using DBs that integrate large-scale medical data for secondary use across different disease areas. Among the DB classifications, administrative claims DBs (70%, 158/225) were most commonly used, while pharmacy DBs were used in only three studies. The largest number of reported studies were associated with cardiovascular, respiratory, and infectious diseases. Outcomes were often inpatient diagnosis, and some ideas included defining effectiveness based on drug use. While various outcomes were uniformly used in studies for the treatment of infectious diseases and respiratory organs, death (overall survival [OS]) and drug continuation (progression-free survival [PFS]) in patients with cancer, laboratory values in the endocrine system (mainly diabetes) were used as the main outcomes. Outcome validation within the article was limited. New user design (32%, 73/225), propensity score analysis (58%, 131/225), and sensitivity analysis (40%, 90/225) were used as measures to reduce bias in these studies. Sixty-eight studies (30%, 68/225) were supported by pharmaceutical companies.

CONCLUSIONS

This systematic review summarized the status of cross-disease research articles on DB studies on drug effectiveness. While considering the strengths and limitations of DB studies, we hope that our comprehensive results would help to promote appropriate DB studies on drug effectiveness in the postmarketing stage.

Associations of kidney tests at medical facilities and health checkups with incidence of end-stage kidney disease: a retrospective cohort study

No study has assessed the association between no health checkup and end-stage kidney disease (ESKD). This retrospective cohort study, including 69,147 adults aged ≥ 40 years in Japan who were insured by the National Health Insurance and the Late-Stage Medical Care System for the Elderly, assessed the associations of kidney tests at medical facilities and health checkups with incident ESKD. The main exposure was the histories of kidney tests using dipstick urinalysis and/or serum creatinine measurement at medical facilities and checkups in the past year: “checkups,” “no kidney test (without checkup),” and “kidney tests (without checkup)” groups. During the median observational period of 5.0 years, ESKD was observed in 246 (0.8%) men and 124 (0.3%) women. The “no kidney test” group was associated with ESKD in men (adjusted subhazard ratio of “no kidney test” vs. “checkups”: 1.66 [95% confidence interval, 1.04–2.65], but not in women. Age-specific subgroup analyses identified the “no kidney test” group as a high-risk population of ESKD in elderly men (1.30 [0.70–2.41] and 2.72 [1.39–5.33] in men aged 40–74 and ≥ 75 years, respectively). Elderly men with no kidney test at medical facilities and no health checkup were at higher risk of ESKD.

Validity of diagnoses and procedures in Japanese dental claims data

BACKGROUND

Dental claims data have been used for epidemiological studies without establishing the validity of the recorded diagnoses or procedures. The present study aimed to examine the accuracy of diagnoses, procedures, operation time, and the number of teeth recorded in dental claims data.

METHODS

We reviewed the charts of 200 patients who visited and 100 patients who were hospitalized in the Department of General Dentistry, Orthodontics, and Oral and Maxillofacial Surgery in an academic hospital between August 2012 and December 2017. The sensitivity and specificity of the dental claims data for five diseases and 15 procedures were evaluated. We assessed the difference in the number of teeth and duration of general anesthesia between claims data and chart reviews.

RESULTS

Sensitivity was more than 86% for six out of seven diagnoses except for pericoronitis (67%). Specificity ranged from 72% (periodontal disease) to 100% (oral cancer for inpatient). The sensitivity of procedures ranged from 10% (scaling for inpatient) to 100%, and the specificity ranged from 6% (food intake on the day of the surgery) to 100%. The mean (standard deviation [SD]) number of teeth in the chart review was 22.6 (6.8), and in the dental claims was 21.6 (8.6). The mean (SD) operation time was 171.2 (120.3) minutes, while the duration of general anesthesia was 270.9 (171.3) minutes.

CONCLUSIONS

The present study is the first study to validate dental claims data, and indicates the extent of usefulness of each diagnosis and procedure for future dental research using administrative data.

Development of algorithms for identifying patients with Crohn's disease in the Japanese health insurance claims database

Background

Real-world big data studies using health insurance claims databases require extraction algorithms to accurately identify target population and outcome. However, no algorithm for Crohn’s disease (CD) has yet been validated. In this study we aim to develop an algorithm for identifying CD using the claims data of the insurance system.

Methods

A single-center retrospective study to develop a CD extraction algorithm from insurance claims data was conducted. Patients visiting the Kitasato University Kitasato Institute Hospital between January 2015–February 2019 were enrolled, and data were extracted according to inclusion criteria combining the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) diagnosis codes with or without prescription or surgical codes. Hundred cases that met each inclusion criterion were randomly sampled and positive predictive values (PPVs) were calculated according to the diagnosis in the medical chart. Of all cases, 20% were reviewed in duplicate, and the inter-observer agreement (Kappa) was also calculated.

Results

From the 82,898 enrolled, 255 cases were extracted by diagnosis code alone, 197 by the combination of diagnosis and prescription codes, and 197 by the combination of diagnosis codes and prescription or surgical codes. The PPV for confirmed CD cases was 83% by diagnosis codes alone, but improved to 97% by combining with prescription codes. The inter-observer agreement was 0.9903.

Conclusions

Single ICD-code alone was insufficient to define CD; however, the algorithm that combined diagnosis codes with prescription codes indicated a sufficiently high PPV and will enable outcome-based research on CD using the Japanese claims database.

Machine-learning model to predict the cause of death using a stacking ensemble method for observational data

OBJECTIVE

Cause of death is used as an important outcome of clinical research; however, access to cause-of-death data is limited. This study aimed to develop and validate a machine-learning model that predicts the cause of death from the patient's last medical checkup.

MATERIALS AND METHODS

To classify the mortality status and each individual cause of death, we used a stacking ensemble method. The prediction outcomes were all-cause mortality, 8 leading causes of death in South Korea, and other causes. The clinical data of study populations were extracted from the national claims (n = 174 747) and electronic health records (n = 729 065) and were used for model development and external validation. Moreover, we imputed the cause of death from the data of 3 US claims databases (n = 994 518, 995 372, and 407 604, respectively). All databases were formatted to the Observational Medical Outcomes Partnership Common Data Model.

RESULTS

The generalized area under the receiver operating characteristic curve (AUROC) of the model predicting the cause of death within 60 days was 0.9511. Moreover, the AUROC of the external validation was 0.8887. Among the causes of death imputed in the Medicare Supplemental database, 11.32% of deaths were due to malignant neoplastic disease.

DISCUSSION

This study showed the potential of machine-learning models as a new alternative to address the lack of access to cause-of-death data. All processes were disclosed to maintain transparency, and the model was easily applicable to other institutions.

CONCLUSION

A machine-learning model with competent performance was developed to predict cause of death.

Elucidating variations in outcomes among older end-stage renal disease patients on hemodialysis in Fukuoka Prefecture, Japan

Variations in health care outcomes and services potentially indicate resource allocation inefficiency. Therefore, this study was conducted to examine variations in mortality and hospitalization cases among end-stage renal disease (ESRD) patients receiving hemodialysis (HD) care from medical facilities located in 13 secondary medical care areas (SMAs) of Fukuoka prefecture, Japan. The research was designed as a retrospective, cross-sectional study using insurance claims data. The subjects of the study were older patients (over 65 years old) insured by the Fukuoka prefecture’s Latter-Stage Elderly Healthcare Insurance. Using an electronic claims database, we identified patients with chronic kidney disease (CKD) who had received HD care from April 1, 2017 to March 31, 2018. The CKD status was identified using International Classification of Disease, 10th revision code, and HD maintenance status was ascertained using specific insurance procedure codes. A total of 5,243 patients met our inclusion criteria and their records were subsequently reviewed. About 73% (n = 3,809) of patients had admission records during the period studied. Thus, the data regarding hospital length of stay (LOS) and admission costs were analyzed separately. Significant differences in terms of increased risks in hospitalization were evident in a number of SMAs. An increase in mortality risk due to heart failure and malignancy was observed in two separate SMAs. Also, analyzed LOS, total hospitalization cost, and cost per day according to SMAs showed statistically significant variations. The findings highlight the magnitude of the burden of CKD and ESRD in the community. The high prevalence of ESRD, associated mortality, and hospitalized HD patients signal the need for clinicians to assume broader roles in measures against chronic kidney disease through involvement in community awareness programs. To improve patient outcomes, improvement of regional health care provision, the level of medical care, and the development of existing human resources are needed.

Data resource profile: JMDC claims database sourced from health insurance societies

JMDC, Inc. (JMDC) has created a database, using data collected from health insurance societies in Japan, consisting of ledgers of insureds, claims (for hospitalization, outpatient treatment, drug preparation, and dental treatment), and health checkup results. The earliest data are from the claims in January 2005, except dental claims from December 2009 and health checkup results from April 2008. Currently (the end of June 2020), the number of insureds included is approximately 9.8 million. This database is unique for Japan and has the following characteristics: (a) the basic population can be ascertained; (b) standardization is carried out using a dictionary; and (c) anonymized individual IDs can be followed on the basis of a time-series over various periods, with the earliest starting date being January 2005. However, it has certain limitations, in that the disease status and test results cannot be ascertained, and there is insufficient access to data for elderly people.

Current trends in diabetes mellitus database research in Japan

With the widespread use of electronic medical records and administrative claims databases, analytic results from so-called real-world data have become increasingly important in healthcare decision-making. Diabetes mellitus is a heterogeneous condition that involves a broad spectrum of patients. Real-world database studies have been recognised as a powerful tool to understand the impact of current practices on clinical courses and outcomes, such as long-term glucose control, development of microvascular or macro-vascular diseases, and mortality. Diabetes is also a major global health issue and poses a significant social and economic burden worldwide. Therefore, it is critical to understand the epidemiology, clinical course, treatment reality, and long-term outcomes of diabetes to determine realistic solutions to a variety of disease-related issues that we are facing. In the present review, we summarise the healthcare system and large-scale databases currently available in Japan, introduce the results from recent database studies involving Japanese patients with diabetes, and discuss future opportunities and challenges for the use of databases in the management of diabetes.

Variation in the use of percutaneous coronary interventions among older patients with acute coronary syndromes: a multilevel study in Fukuoka, Japan

BACKGROUND

Variation in health care delivery among regions and hospitals has been observed worldwide and reported to have resulted in health inequalities. Regional variation of percutaneous coronary intervention (PCI) was previously reported in Japan. This study aimed to assess the small-area and hospital-level variations and to examine the influence of patient and hospital characteristics on the use of PCI.

METHODS

Data provided by the Fukuoka Prefecture Latter-stage Elderly Insurance Association was used. There were 11,821 patients aged ≥65 years with acute coronary syndromes who were identified from 2015 to 2017. Three-level multilevel logistic regression analyses were performed to quantify the small-area and hospital variations, as well as, to identify the determinants of PCI use.

RESULTS

The results showed significant variation (δ² = 0.744) and increased PCI use (MOR = 2.425) at the hospital level. After controlling patient- and hospital-level characteristics, a large proportional change in cluster variance was found at the hospital level (PCV 14.7%). Fixed-effect estimation results showed that females, patients aged ≥80 years old, hypertension and dyslipidemia had significant association with the use of PCI. Hospitals with high physician density had a significantly positive relationship with PCI use.

CONCLUSIONS

Patients receiving care in hospitals located in small areas have equitable access to PCI. Hospital-level variation might be originated from the oversupply of physicians. A balanced number of physicians and beds should be taken into consideration during healthcare allocation. A treatment process guideline on PCI targeting older patients is also needed to ensure a more equitable access for healthcare resources.

Validation of Acute Myocardial Infarction and Heart Failure Diagnoses in Hospitalized Patients With the Nationwide Claim-Based JROAD-DPC Database

Background: Big data systems such as diagnosis procedure combination (DPC) datasets have recently been used for research purposes. However, there have been few validation studies to determine the accuracy of diagnoses. The aim of this study was to validate and evaluate 2 diagnoses, namely acute myocardial infarction (AMI) and heart failure (HF), using International Classification of Diseases, 10th revision (ICD-10) codes in the Japanese Registry Of All cardiac and vascular Disease (JROAD)-DPC database.

Methods and Results: ICD-10 codes I21.0–I21.9 and I50.0–I50.9 were used to identify AMI and HF, respectively, in the JROAD-DPC database. Diagnoses of AMI and HF were validated in clinical datasets assessing sensitivity and positive predictive value (PPV). Over 1–2 years, 742 patients hospitalized for AMI and 1,368 patients hospitalized for HF were identified in the DPC dataset. Sensitivity and PPV for AMI were 78.9% and 78.8%, respectively. When emergency hospitalization was included as a criterion, PPV increased to 84.9%. For HF, sensitivity and PPV were 84.7% and 57.0%, respectively. When emergency hospitalization and acute HF were included as criteria, PPV increased to 83.0%.

Conclusions: Using ICD-10 codes for AMI and HF diagnoses among hospitalized patients, the DPC dataset showed acceptable concordance with clinical datasets. PPV increased when any conditions of hospitalization were included, especially in HF.

Real-World Bleeding and Ischemic Events in Asian Patients on P2Y12-Inhibitors After Percutaneous Coronary Intervention: A National Claims Data Analysis

Introduction

The safety and effectiveness of potent P2Y12 inhibitors in East Asians have been questioned because of the higher bleeding tendency and lower thrombotic risk in this population. We comparatively evaluated the safety, effectiveness and treatment persistence of the dual antiplatelet therapies (DAPT) with clopidogrel (CDAPT), ticagrelor (TDAPT) and prasugrel (PDAPT) after percutaneous coronary intervention (PCI) in the Korean population.

Methods

A retrospective cohort study was conducted using Korean National Health Insurance claims data. In 57,197 patients treated with DAPT after PCI, the risk of bleeding events, risk of major adverse cardiac and cerebral events (MACCE: a composite of all-cause death, myocardial infarction [MI], stroke and revascularization), risk of net adverse clinical events (NACE) and persistence and adherence rates were assessed with stabilized inverse probability of treatment weighting.

Results

TDAPT was associated with higher risks of bleeding (1 year: hazard ratio [HR], 1.37; 95% confidence interval [CI] 1.28–1.46; prolonged: HR 1.39, 95% CI 1.31–1.47), MACCE (1 year: HR 1.10, 95% CI 1.03–1.18; prolonged: HR 1.24, 95% CI 1.16–1.31) and NACE (1 year: HR 1.23, 95% CI 1.18–1.29; prolonged: HR 1.31, 95% CI 1.25–1.36) than CDAPT both at 1 year and in the prolonged periods, whereas there were no significant differences between PDAPT and CDAPT. Similar results were also observed in a subgroup analysis of patients with baseline MI. CDAPT was associated with higher persistence and adherence rates than TDAPT and PDAPT.

Conclusions

CDAPT was associated with clinical outcomes that were more favorable than those in TDAPT and comparable to those in PDAPT and drug persistence and adherence that were higher than in TDAPT or PDAPT. Clopidogrel may remain a viable first option for post-PCI DAPT in East Asian patients with a low thrombotic risk and a high bleeding tendency.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01526-4) contains supplementary material, which is available to authorized users.

Impact of class-level labelling change on prescriptions of antidepressants for adolescents: An interrupted time-series study using a health insurance claims database in Japan, 2005-2013

BACKGROUND

In October 2007, the Japanese Health Authority directed that precautions be added to antidepressants (ADs) labelling regarding suicide risk among young people. This study evaluates the impact of the labelling change on AD prescriptions and Japanese adolescent suicide rates.

METHODS

We compared AD prescription rates per 100,000 population as a primary outcome. The intervention group comprised adolescents (10-24 years), while the control group comprised adults (25-64 years). We defined the pre-intervention period as January 2005 to October 2007 and post-intervention as November 2007 to February 2013. Monthly prescription rate data from a commercial claims database were triangulated with annual suicide rates in Japan. We performed segmented regression analysis for the prescription rates, using a quasi-Poisson model, and tested for level and trend changes.

RESULTS

The commercial claims database included 152,686 adolescents and 195,251 adults during the pre-intervention period and 846,367 adolescents and 1,352,453 adults during post-intervention. Post-intervention, the overall AD prescription rates decreased only in adult males (-95.8 prescription per 100,000) but increased in all other groups. The mean annual suicide rate increased in adolescent males (+1.5 suicides per 100,000) but decreased in all other groups. Overall, the upward trend became moderate or inverse in all groups post-intervention but with a large difference between males and females. The suicide rates rose slightly in adolescents but began declining in adults a year post-intervention. In females, changes in level, trend, and suicide rates were very small in both adolescents and adults.

CONCLUSIONS

Contrary to expectations, the mean prescription rates only decreased in adult males, but not in adolescents, regardless of gender. Downward level and trend change were clearly observed in adult males but not in adolescents, the original target of the updated warning. There were no clear temporal associations between suicide rates and the labelling change in either group.

A comparison of the safety and effectiveness of prasugrel and clopidogrel in younger population undergoing percutaneous coronary intervention: A retrospective study using a Japanese claims database

BACKGROUND

Prasugrel inhibits platelet aggregation more potently than clopidogrel. In the global phase III trial, prasugrel [loading dose/maintenance dose (LD/MD), 60/10 mg] reduced the incidence of ischemic events but involved a higher risk of hemorrhage than clopidogrel in patients with acute coronary syndromes who were scheduled to undergo percutaneous coronary intervention (PCI). In the Japanese phase III trial for similar patients wherein the prasugrel dose regimen was adjusted (LD/MD, 20/3.75 mg), the efficacy of prasugrel and clopidogrel were comparable to that in the global trial; however, the safety could not be determined due to limited power. Given the strict enrollment criteria, the results of the Japanese phase III trial may not be applicable to routine clinical practice. We compared the safety and effectiveness of prasugrel and clopidogrel in the real-world setting in Japanese patients.

METHODS

With an analysis of a large claims database prepared during the post-marketing stages in Japan, we identified patients undergoing PCI and compared the incidence of bleeding and ischemic coronary events between patients who received prasugrel and those receiving clopidogrel.

RESULTS

Between January 1, 2014 and December 31, 2018, we identified 1977 patients who were scheduled to undergo urgent PCI (urgent PCI cohort) and 1922 who were scheduled to undergo elective PCI (elective PCI cohort). After propensity-score matching, there were no significant differences in the baseline clinical characteristics of the prasugrel and clopidogrel groups in the urgent (n = 1080) and elective PCI (n = 1626) cohorts. In Cox proportional hazard analyses, there were no significant differences in the incidence of bleeding or ischemic coronary events during the median 8-month follow-up in both cohorts.

CONCLUSIONS

The safety and effectiveness of prasugrel was comparable to that of clopidogrel in real-world Japanese patients scheduled to undergo PCI.

The Certainty Framework for Assessing Real-World Data in Studies of Medical Product Safety and Effectiveness

A fundamental question in using real-world data for clinical and regulatory decision making is: How certain must we be that the algorithm used to capture an exposure, outcome, cohort-defining characteristic, or confounder is what we intend it to be? We provide a practical framework to help researchers and regulators assess and classify the fit-for-purposefulness of real-world data by study variable for a range of data sources. The three levels of certainty (optimal, sufficient, and probable) must be considered in the context of each study variable, the specific question being studied, the study design, and the decision at hand.

Validity of Claims Diagnosis Codes for Cardiovascular Diseases in Diabetes Patients in Japanese Administrative Database

Background

Observational studies using large claims databases for diabetes patients have been increasingly conducted. While validation of outcomes is important in such studies, validation studies from Japan are still scarce and small in scale with questions remaining on the representativeness of their findings. We examined the positive predictive value (PPV) of outcomes that often develop in type 2 diabetes patients: cardiovascular outcomes including congestive heart failure (CHF), myocardial infarction (MI), stroke-related diseases, and renal outcomes including end stage renal disease (ESRD), and death using a large Japanese database containing administrative claims and electronic medical record (EMR) data.

Patients and Methods

We used patient-level administrative claims data from 2003 and EMR data from 1985 to the most recent data up to December 2018 provided by Real World Data Co., Ltd. The database consisted of data from over 200 hospitals including ≥12 million uniquely identifiable patients. Among patients who had ≥1 type 2 diabetes diagnosis in the EMR, those who had administrative claims for each outcome were identified, and then the PPV was calculated for each outcome using the EMR as the gold standard.

Results

The numbers of patients identified for each outcome were 1,700 for MI, 2,027 for hemorrhagic stroke, 3,722 for ESRD, 4,723 for ischemic stroke, 5,404 for CHF, 6,678 for any type of stroke, and 10,815 for death. PPVs ranged from 67.4% for ESRD, 78.7% for MI, 80.3% for death, 85.7% for ischemic stroke, 88.9% for any type of stroke, 89.9% for hemorrhagic stroke, and 95.7% for CHF. A post hoc analysis showed PPV for ESRD as 83.8%.

Conclusion

This large-scale validation study on diagnosis in administrative claims showed reasonable PPVs for the outcomes. We believe that the definitions of outcomes can be considered to be appropriate for future studies using Japanese administrative claims data.

Validation of claims data to identify death among aged persons utilizing enrollment data from health insurance unions

The identification of death is critical for epidemiological research. Despite recent developments in health insurance claims databases, the quality of death information in claims is not guaranteed because health insurance claims are collected primarily for reimbursement. We aimed to examine the usefulness and limitations of death information in claims data and to examine methods for improving the quality of death information for aged persons.

We used health insurance claims data and enrollment data (as the gold standard) from September 2012 through August 2015 for nondependent persons aged 65–74 years enrolled in Japanese workplace health insurance. Overall, 3,710,538 insured persons were registered in the database during the study period. We analyzed 45,441 eligible persons. Inpatient and outpatient deaths were identified from the discharge/disease status in the claims, with sensitivities of 94.3% and 47.4%, specificities of 98.5% and 99.9%, and PPVs of 96.3% and 95.7%, respectively, using enrollment data as the gold standard. For outpatients, death defined as a combination of disease status and charge data for terminal care still indicated low sensitivity (54.7%).

The validity of death information in inpatient claims was high, suggesting its potential usefulness for identifying death. However, given the low sensitivity for outpatient deaths, the use of death information obtained solely from records in outpatient claims is not recommended.

Individual mortality information in the German Pharmacoepidemiological Research Database (GePaRD): a validation study using a record linkage with a large cancer registry

OBJECTIVE

Claims data need to be validated to assess their use for epidemiological research. This study aimed to examine the validity of mortality information in the German Pharmacoepidemiological Research Database (GePaRD).

DESIGN

Validation study, secondary data, medical claims.

SETTING

Claims data of two German nationwide acting statutory health insurance providers (SHIs) contributing data for GePaRD; record linkage with epidemiological cancer registry providing individual official mortality information.

PARTICIPANTS

All women insured with the two SHIs whose insurance coverage ended in the period 2006-2013 and who were residents of North Rhine Westphalia.

MEASURES

Descriptive statistics were used to analyse the performance of the linkage procedure. Further, we calculated measures of agreement between the official and the GePaRD-based vital status and assessed differences between the official and the GePaRD-based date of death.

RESULTS

Of the 256 111 women of the linkage sample, 25 528 were classified as 'deceased' in GePaRD and the others as 'alive'. Compared with the official data, the GePaRD-based vital status showed a sensitivity of 95.9% and a specificity of 99.4%. The negative predictive value was 99.6% and the positive predictive value 94.3%. The date of death agreed in 96.3% between both data sources.

CONCLUSIONS

The vital status recorded in GePaRD was of high accuracy and discrepancies between dates of death in GePaRD and official dates were rare. This underlines the potential of the database for conducting large cohort studies with mortality as the endpoint.

Positive predictive value of ICD-10 codes for acute myocardial infarction in Japan: a validation study at a single center

Background

In Japan, several large healthcare databases have become available for research since the early 2000’s. However, validation studies to examine the accuracy of these databases remain scarce. We conducted a validation study in order to estimate the positive predictive value (PPV) of local or ICD-10 codes for acute myocardial infarction (AMI) in Japanese claims. In particular, we examined whether the PPV differs between claims in the Diagnosis Procedure Combination case mix scheme (DPC claims) and in non-DPC claims.

Methods

We selected a random sample of 200 patients from all patients hospitalized at a large tertiary-care university hospital between January 1, 2009 and December 31, 2011 who had an inpatient claim assigned a local or ICD-10 code for AMI. We used a standardized data abstraction form to collect the relevant information from an electronic medical records system. Abstracted information was then categorized by a single cardiologist as being either definite or not having AMI.

Results

In a random sample of 200 patients, the average age was 67.7 years and the proportion of males was 78.0%. The PPV of the local or ICD-10 code for AMI was 82.5% in this sample of 200 patients. Further, of 178 patients who had an ICD-10 code for AMI based on any of the 7 types of condition codes in the DPC claims, the PPV was 89.3%, whereas of the 161 patients who had an ICD-10 code for AMI based on any of 3 major types of condition codes in the DPC claims, the PPV was 93.8%.

Conclusion

The PPV of the local or ICD-10 code for AMI was high for inpatient claims in Japan. The PPV was even higher for the ICD-10 code for AMI for those patients who received AMI care through the DPC case mix scheme. The current study was conducted in a single center, suggesting that a multi-center study involving different types of hospitals is needed in the future. The accuracy of condition codes for DPC claims in Japan may also be worth examining for conditions other than AMI such as stroke.

Follow-up tests and outcomes for patients undergoing percutaneous coronary intervention: analysis of a Japanese administrative database

Follow-up tests after percutaneous coronary intervention (PCI) are considered inappropriate for asymptomatic patients. Despite this perception, many cardiologists conduct follow-up tests as routine practice. The objective of this study was to investigate the survival benefits of follow-up testing after PCI in a real-world setting in Japan. A nationwide Japanese administrative database was used to identify unselected patients who underwent PCI with stent implantation between January 2010 and December 2013. We used time-dependent Cox proportional hazards models to evaluate the association between follow-up testing and outcomes. The primary outcome was the composite of all-cause death and acute myocardial infarction (AMI). Among a total of 21,409 patients, 15,095 (70.5%) completed follow-up testing, of whom 9814 (45.0%) underwent coronary angiography. During a median of 2.7 years of observation, the primary outcome occurred less frequently for patients who underwent follow-up testing (1.21 vs. 4.51% per year; adjusted hazard ratio, 0.59; 95% CI 0.52-0.67; p < 0.001). Individual rates of all-cause death and AMI were also lower for the patients who underwent follow-up testing. Follow-up testing was associated with a lower risk of all-cause death and/or AMI. However, because of the unexpectedly large effect and many limitations of the administrative data, our findings should be further investigated to assess the net benefit of follow-up tests. In addition, we do not intend to encourage routine follow-up tests for patients without clear clinical indications. Follow-up tests should be conducted in accordance with clinical indications.

Analysis of the evidence-practice gap to facilitate proper medical care for the elderly: investigation, using databases, of utilization measures for National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB)

As Japan becomes a super-aging society, presentation of the best ways to provide medical care for the elderly, and the direction of that care, are important national issues. Elderly people have multi-morbidity with numerous medical conditions and use many medical resources for complex treatment patterns. This increases the likelihood of inappropriate medical practices and an evidence-practice gap. The present study aimed to: derive findings that are applicable to policy from an elucidation of the actual state of medical care for the elderly; establish a foundation for the utilization of National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), and present measures for the utilization of existing databases in parallel with NDB validation.

Cross-sectional and retrospective cohort studies were conducted using the NDB built by the Ministry of Health, Labor and Welfare of Japan, private health insurance claims databases, and the Kyoto University Hospital database (including related hospitals). Medical practices (drug prescription, interventional procedures, testing) related to four issues—potential inappropriate medication, cancer therapy, chronic kidney disease treatment, and end-of-life care—will be described. The relationships between these issues and clinical outcomes (death, initiation of dialysis and other adverse events) will be evaluated, if possible.

Validating mortality in the German Pharmacoepidemiological Research Database (GePaRD) against a mortality registry

PURPOSE

The study aimed at validating the status and date of death of a large electronic health insurance database against data of a mortality registry, using a probabilistic record linkage.

METHODS

Data were obtained from one local health insurance company contributing to the German Pharmacoepidemiological Research Database (GePaRD). Furthermore, data of the Bremen Mortality Index (BreMI) containing all information from death certificates were used as reference information. Both data sources were probabilistically linked. The study sample consisted of insurants dying in 2005 or 2006.

RESULTS

Of 3245 deaths in GePaRD, 83.7% were successfully linked to BreMI records. The linkage success did not differ between men and women, age groups or insurance status groups. Date of death was accurate in 97.1% of all linked deaths.

CONCLUSIONS

The accuracy of the status of death in GePaRD is likely to be underestimated in this study because of factors related to the record linkage procedure leading to failure of the probabilistic record linkage approach and the limited completeness of BreMI. A previous validation study comparing aggregate mortality information in GePaRD with German national statistics did not indicate an overreporting of deaths in GePaRD. Thus, a higher accuracy of the status of death in GePaRD than estimated here can be assumed. Copyright © 2016 John Wiley & Sons, Ltd.

Prevalence, prescribed quantities, and trajectory of multiple prescriber episodes for benzodiazepines: A 2-year cohort study

BACKGROUND

Little is known about the use of multiple prescribers for benzodiazepines, which might reflect fragmented patient care and increases the risk of hospital admission for drug dependence or poisoning. Therefore, we aimed to identify the prevalence, prescribed quantities, and trajectory of multiple prescriber episodes for benzodiazepines.

METHODS

We conducted a 2-year cohort study of 1178,361 recipients aged 0-74 years using a large health insurance claims database in Japan. We quantified multiple prescriber episodes for benzodiazepines occurring in ambulatory care settings in a baseline and subsequent year by (1) counting the number of unique providers within a 12-month period, (2) calculating the maximum number of unique providers within a single month, and (3) identifying consecutive overlapping prescriptions of over 30 days duration.

RESULTS

Among 58,314 patients with a benzodiazepine prescription during the baseline year, 282 (0.5%) filled prescriptions from four or more providers within a 12-month period, 439 (0.8%) filled prescriptions from three or more providers within a single month, and 757 (1.3%) filled consecutive overlapping prescriptions. The odds for multiple prescriber episodes were significantly higher among patients with multiple chronic conditions. Consecutive overlapping prescriptions had the best accuracy to detect patients with potentially questionable prescribed quantities as well as to predict those with multiple prescriber episodes in the subsequent year.

CONCLUSIONS

These results highlight the need for pharmacists to increase their involvement in prescription oversight and for health insurance agencies to implement a prescription monitoring program to screen for patients with multiple prescriber episodes for benzodiazepines.

Methodological issues in observational studies and non-randomized controlled trials in oncology in the era of big data

Non-randomized controlled trials, cohort studies and database studies are appealing study designs when there are urgent needs for safety data, outcomes of interest are rare, generalizability is a matter of concern, or randomization is not feasible. This paper reviews four typical case studies from methodological viewpoints and clarifies how to minimize bias in observational studies in oncology. In summary, researchers planning observational studies should be cautious of selection of appropriate databases, validity of algorithms for identifying outcomes, comparison with incident users or self-control, rigorous collection of information on potential confounders and reporting details of subject selection. Further, a careful study protocol and statistical analysis plan are also necessary.

Prescribing pattern of anti-Parkinson drugs in Japan: a trend analysis from 2005 to 2010

Objective

Therapeutic options for Parkinson's disease mainly consist of L-dopa and dopamine agonists. However, in Japan, the product labeling of the ergot dopamine agonists, cabergoline and pergolide, was revised in April 2007 due to the risk of developing cardiac valvulopathy. Here, we describe the prescribing trends of anti-Parkinson drugs from 2005 through 2010 in Japan, and examined whether these trends changed after the drug safety measures in 2007.

Methods and Patients

We used medical claim data from January 2005 to December 2010 for Parkinson's disease patients older than 30 years who were prescribed anti-Parkinson drugs. We calculated the proportion of patients prescribed each drug for each year, and compared the proportions of first-line drugs prescribed before and after April 2007. We also examined the prescription variations of cabergoline/pergolide users one year before or after April 2007.

Results

L-dopa was the most frequently prescribed drug for Parkinson's disease (2005, 58%; 2010, 51%). The proportion of patients prescribed ergot dopamine agonists markedly decreased and non-ergot dopamine agonists increased after 2007. Among first-line drugs, the proportion of non-ergot agents increased after April 2007. Among 54 cabergoline/pergolide users, 24 (44%) discontinued these drugs, nine of whom switched to non-ergot agents.

Conclusion

L-dopa was the mainstay of Parkinson's disease treatment between 2005 and 2010 in Japan. There was a decrease in ergot agents and an increase in non-ergot agents prescribed after the regulatory actions in 2007.

Validity of physician billing claims to identify deceased organ donors in large healthcare databases

Objective

We evaluated the validity of physician billing claims to identify deceased organ donors in large provincial healthcare databases.

Methods

We conducted a population-based retrospective validation study of all deceased donors in Ontario, Canada from 2006 to 2011 (n = 988). We included all registered deaths during the same period (n = 458,074). Our main outcome measures included sensitivity, specificity, positive predictive value, and negative predictive value of various algorithms consisting of physician billing claims to identify deceased organ donors and organ-specific donors compared to a reference standard of medical chart abstraction.

Results

The best performing algorithm consisted of any one of 10 different physician billing claims. This algorithm had a sensitivity of 75.4% (95% CI: 72.6% to 78.0%) and a positive predictive value of 77.4% (95% CI: 74.7% to 80.0%) for the identification of deceased organ donors. As expected, specificity and negative predictive value were near 100%. The number of organ donors identified by the algorithm each year was similar to the expected value, and this included the pre-validation period (1991 to 2005). Algorithms to identify organ–specific donors performed poorly (e.g. sensitivity ranged from 0% for small intestine to 67% for heart; positive predictive values ranged from 0% for small intestine to 37% for heart).

Interpretation

Primary data abstraction to identify deceased organ donors should be used whenever possible, particularly for the detection of organ-specific donations. The limitations of physician billing claims should be considered whenever they are used.