Development and validation of claims-based algorithms for identifying hospitalized patients with COVID-19 and their severity in 2020 and 2021.

BACKGROUND: This study aimed to develop and validate claims-based algorithms for identifying hospitalized patients with coronavirus disease (COVID-19) and the disease severity. METHODS: We used claims data including all patients at the National Center for Global and Medicine Hospital between January 1, 2020, and December 31, 2021. The claims-based algorithms for three statuses with COVID-19 (hospitalizations, moderate or higher status, and severe status) were developed using diagnosis codes (ICD-10 code: U07.1, B34.2) and relevant medical procedure code. True cases were determined using the COVID-19 inpatient registry and electronic health records. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each algorithm at 6-month intervals. RESULTS: Of the 75,711 total patients, number of true cases was 1,192 for hospitalizations, 622 for moderate or higher status, and 55 for severe status. The diagnosis code-only algorithm for hospitalization had sensitivities 90.4% to 94.9% and PPVs 9.3% to 19.4%. Among the algorithms consisting of both diagnosis codes and procedure codes, high sensitivity and PPV were observed during the following periods; 93.9% and 97.1% for hospitalization (January-June 2021), 90.4% and 87.5% for moderate or higher status (July-December 2021), and 92.3% and 85.7% for severe status (July-December 2020), respectively. Almost all algorithms had specificities and NPVs of approximately 99%. CONCLUSIONS: The diagnosis code-only algorithm for COVID-19 hospitalization showed low validity throughout the study period. The algorithms for hospitalizations, moderate or higher status, and severe status with COVID-19, consisting of both diagnosis codes and procedure codes, showed high validity in some periods.

Increased risk of hypocalcemia with decreased kidney function in patients prescribed bisphosphonates based on real-world data from the MID-NET® in Japan: a new-user cohort study.

BACKGROUND: In the post-marketing stage, cases of hypocalcemia associated with bisphosphonate preparations (BPs) have been reported in patients with decreased kidney function, despite warning against use of BPs in such patients in the package insert (PI) of Japan. The purpose of this study was to investigate the safety of BPs in patients with decreased kidney function. METHODS: The cohort study was conducted in patients with osteoporosis and newly prescribed bisphosphonate utilizing real-world data from MID-NET® in Japan. The adjusted hazard ratios (aHRs) for hypocalcemia (a corrected serum Ca level < 8.00 mg/dL) relative to the normal group were calculated in each decreased kidney function group (mild, moderate or severe group). RESULTS: A total of 14,551 patients were included in the analysis, comprising 2,601 (17.88%) with normal (eGFR ≥ 90 mL/min/1.73m2), 7,613 (52.32%) with mild (60 ≤ eGFR < 90 mL/min/1.73m2), 3,919 (26.93%) with moderate (30 ≤ eGFR < 60 mL/min/1.73m2), and 418 (2.87%) with severe kidney function (eGFR < 30 mL/min/1.73m2). The aHRs (95% confidence interval) for hypocalcemia were 1.85 (0.75-4.57), 2.30 (0.86-6.21), and 22.74 (8.37-61.78) in the mild, moderate, and severe groups, respectively. The increased risk of hypocalcemia depending on kidney function was also observed even when calculating the aHR for each specific BP such as alendronate sodium hydrate, minodronic acid hydrate, and sodium risedronate hydrate. Furthermore, similar results were obtained in the sensitivity analysis by altering the outcome definition to a 20% or more reduction in corrected serum Ca level from the baseline, as well as when focusing on patients with more than one laboratory test result per 30 days during the follow-up period. CONCLUSIONS: These findings suggest that the risk of hypocalcemia during BP prescription is higher in patients with decreased kidney function, particularly those with severely decreased kidney function. The quantitative real-world evidence on the safety risk of BPs obtained in this study has led to the PI revision describing a relationship between hypocalcemia risk and decreased kidney function as a regulatory action in Japan and will contribute to promoting the proper use of BPs with appropriate risk management in clinical practice.

The Longevity Improvement & Fair Evidence (LIFE) Study: Overview of the Study Design and Baseline Participant Profile.

BACKGROUND: The Longevity Improvement & Fair Evidence (LIFE) Study, which was launched in 2019, is a multi-region community-based database project that aims to generate evidence toward extending healthy life expectancy and reducing health disparities in Japan. Herein, we describe the LIFE Study's design and baseline participant profile. METHODS: Municipalities participating in the LIFE Study provide data from government-administered health insurance enrollees and public assistance recipients. These participants cover all disease types and age groups. Centered on healthcare claims data, the project also collects long-term care claims data, health checkup data, vaccination records, residence-related information, and income-related information. The different data types are converted into a common data model containing five modules (health care, long-term care, health checkup, socioeconomic status, and health services). We calculated the descriptive statistics of participants at baseline in 2018. RESULTS: The LIFE Study currently stores data from 1,420,437 residents of 18 municipalities. The health care module contains 1,280,756 participants (mean age: 65.2 years), the long-term care module contains 189,069 participants (mean age: 84.3 years), and the health checkup module contains 274,375 participants (mean age: 69.0 years). Although coverage and follow-up rates were lower among younger persons, the health care module includes 74,151 children (0-19 years), 273,157 working-age adults (20-59 years), and 933,448 older persons (≥60 years). CONCLUSION: The LIFE Study provides data from over 1 million participants and can facilitate a wide variety of life-course research and cohort studies. This project is expected to be a useful platform for generating real-world evidence from Japan.

Effectiveness of BNT162b2 against infection, symptomatic infection, and hospitalization among older adults aged ≥65 years during the Delta variant predominance in Japan: The VENUS Study.

BACKGROUND: We evaluated the effectiveness of the BNT162b2 vaccine against infection, symptomatic infection, and hospitalization in older people during the Delta-predominant period (July 1 to September 30, 2021). METHODS: We performed a population-based cohort study in an older adult population aged ≥65 years using data from the Vaccine Effectiveness, Networking, and Universal Safety Study conducted from January 1, 2019, to September 30, 2021, in Japan. We matched BNT162b2 vaccinated and unvaccinated individuals in a 1:1 ratio on the date of vaccination of the vaccinated individual. We evaluated the effectiveness of the vaccine against infection, symptomatic infection, and COVID-19-related hospitalization by comparing the vaccinated and unvaccinated groups. We estimated the risk ratio and risk difference using the Kaplan-Meier method with inverse probability weighting. The vaccine effectiveness was calculated as (1 - risk ratio) × 100%. RESULTS: The study included 203,574 matched pairs aged ≥65 years. At 7 days after the second dose, the vaccine effectiveness (95% confidence interval) of BNT162b2 against infection, symptomatic infection, and hospitalization was 78.1% (65.2 to 87.8%), 79.1% (64.6 to 88.9%), and 93.5% (83.7 to 100%), respectively. CONCLUSIONS: BNT162b2 was highly effective against infection, symptomatic infection, and hospitalization in Japan's older adult population aged ≥65 years during the Delta-predominant period.

Cardiovascular risks associated with dipeptidyl peptidase-4 inhibitors monotherapy compared with other antidiabetes drugs in the Japanese population: A nationwide cohort study.

PURPOSE: We evaluated the cardiovascular risk associated with dipeptidyl peptidase-4 inhibitors (DPP-4Is) as monotherapy compared with other antidiabetic drugs in Japan. METHODS: We conducted a nationwide cohort study involving 2 716 000 diabetes patients in Japan. New users of any antidiabetic drug as monotherapy between 1 April 2010 and 31 October 2014 were identified. Occurrences of myocardial infarction (MI), heart failure (HF), and stroke requiring hospitalization associated with DPP-4Is were compared with those associated with biguanides (BGs), sulfonylureas (SUs), or α-glucosidase inhibitors (α-GIs). Adjusted hazard ratios (aHRs) for these outcomes were estimated by Cox proportional hazards model. Propensity score standardization was used to control for confounding. RESULTS: We identified 1 105 103 patients using DPP-4Is, 278 280 patients using BGs, 273 449 patients using SUs, and 217 026 patients using α-GIs. The risks of MI and HF for DPP-4I users were significantly higher than those for BG users (MI: aHR, 1.48 [95%CI, 1.20-1.82], HF: aHR, 1.46 [95%CI, 1.31-1.62]), while significantly lower than those for SU users (MI: aHR, 0.84 [95%CI, 0.72-0.98], HF: aHR, 0.86 [95%CI, 0.81-0.92]). The risk of MI for DPP-4I users was similar to that for α-GI users, while the risk of HF for DPP-4I users was slightly higher than for α-GI users (MI: aHR, 0.98 [95%CI, 0.82-1.17], HF: aHR, 1.12[95%CI, 1.04-1.21]). CONCLUSIONS: Risk of MI and HF requiring hospitalization associated with DPP-4Is as monotherapy was significantly higher than BGs, significantly lower than SUs, and similar to α-GIs.

The utilization and challenges of Japan's MID-NET® medical information database network in postmarketing drug safety assessments: A summary of pilot pharmacoepidemiological studies.

PURPOSE: To examine the potential role of Medical Information Database Network (MID-NET® ), a newly established Japanese medical information database network, in postmarketing drug safety assessments through the characterization of its advantages and limitations in five pilot studies. METHODS: The pilot studies were designed to address three major objectives in postmarketing drug safety assessments, ie, the examination of actual drug utilization, the impact of safety-related regulatory actions, and drug-associated risks. The five studies were conducted on the following topics: (a) utilization of codeine-containing products and its relationship with respiratory depression, (b) impact of a Dear Healthcare Professional letter on hypocalcemia incidence associated with denosumab (Ranmark® ) use, (c) risk of acute myocardial infarction associated with antidiabetic drug use, (d) risk of glucose metabolism disorders associated with atypical antipsychotic drug use, and (e) prospective monitoring of abnormal laboratory test results during new drug prescriptions. RESULTS: The pilot studies were successfully conducted and demonstrated the value of MID-NET® in postmarketing drug safety assessments. In particular, the ability to utilize laboratory test results as objective clinical indicators is a major advantage of this database. Potential limitations include a relatively small sample size and a lack of patient-level data linkages among hospitals. CONCLUSIONS: MID-NET® was confirmed to be a valuable database for postmarketing drug safety assessments. The use of laboratory test results to define clinical outcomes may allow more objective and accurate analyses to be conducted. These studies furthered our understanding of the characteristics of MID-NET® , including its advantages and limitations.

The association between concerns toward adverse reactions during pre-approval drug reviews and the post-approval addition of clinically significant adverse reactions to package inserts: A retrospective analysis of pre-approval drug review reports and safety updates.

PURPOSE: To determine if concerns toward adverse reactions (ARs) identified during the drug approval process are associated with their post-approval addition to package inserts. METHODS: Pre-approval concerns toward 24 target ARs were identified in the drug review reports and initial package inserts of 126 target drugs approved for use in Japan between April 2004 and March 2009. Each target drug was monitored for 5 years after approval for the addition of these ARs as clinically significant adverse reactions (CSARs) in the package inserts. Positive predictive values (PPVs) and negative predictive value (NPVs) were calculated. The odds ratios (ORs) and 95% confidence intervals (CIs) were also analyzed to test the association between pre-approval concerns and post-approval CSAR additions. RESULTS: Target ARs with pre-approval concerns were added as CSARs in 88 of 406 AR-drug pairs (PPV: 21.7%). In contrast, target ARs without pre-approval concerns were added as CSARs in 93 of 2304 drugs (NPV: 96.0%). Hypoglycemia had the highest PPV (100%), whereas hepatitis and myocardial infarction had the lowest PPVs (0.0%). Abnormal hepatic function had the lowest NPV (85.4%), whereas myocardial infarction and convulsions had the highest NPVs (100%). Pre-approval concerns showed a significantly positive association with post-approval CSAR additions (OR: 6.57, 95% CI: 4.74, 9.11; P < 0.001). CONCLUSIONS: The significant association between pre-approval concerns and post-approval CSAR additions indicates that Japan's drug regulatory agency has generally conducted rigorous examination of the safety information available in the submitted data packages during drug review for approval.

Analysis of safety-related regulatory actions by Japan's pharmaceutical regulatory agency.

PURPOSE: To evaluate the safety-related regulatory actions implemented by Japan's Pharmaceuticals and Medical Devices Agency (PMDA) in 2012. METHODS: We analyzed serious safety issues appended to drug package inserts (PIs) in Japan in 2012. The issues were characterized according to drug class, adverse event, years since drug approval, initiator of regulatory actions, revised section of PI, and evidence source. We also quantified the durations from signal detection to tentative decision and from tentative decision to regulatory action. RESULTS: We identified 144 serious safety issues during the study period, and the majority of evidence originated from spontaneous reports (83.5%). The PMDA initiated regulatory actions for half of all safety issues, and the median duration from drug approval to regulatory action was 8 years (interquartile range [IQR], 3-26.5 years). The median duration was 49 days (IQR, 0-362 days) from signal detection to tentative decision and 84 days (IQR, 63-136 days) from tentative decision to regulatory action. Several safety issues involving older drugs and multiple products had protracted decision-making durations. CONCLUSIONS: Most safety issues led to prompt regulatory actions predominantly based on spontaneous reports. Some safety issues that were not easily detected by the spontaneous reporting system were identified years after approval. In addition, several safety issues required assessments of multiple drug products, which prolonged the decision-making process.

Post-approval appending of CSARs to drug package inserts: an analysis of the types of adverse reactions and time to addition.

PURPOSE: The aim of this study was to quantitatively analyze clinically significant adverse reactions (CSARs) added to drug package inserts after approval and to investigate the time to these post-approval additions as an indicator of safety-related regulatory actions. METHODS: Drugs containing new active ingredients that had been approved in Japan from April 2001 to December 2010 were analyzed. We examined CSARs that had been reported in the first version of the package inserts and subsequent additions through notifications from Japan's Ministry of Health, Labour and Welfare until the end of 2011. Relative risks (RRs) for post-approval addition of CSARs were calculated for various categories of disorders. The median lengths of time to post-approval addition of CSARs were compared. RESULTS: A total of 238 drugs were examined. Of the 2487 CSARs associated with these drugs, 737 had been added after approval. The analysis revealed a higher likelihood for post-approval addition of CSARs for "Hepatobiliary disorders" (RR: 1.41; 95% confidence interval [CI]: 1.19-1.68), "Gastrointestinal disorders" (RR: 1.35; 95%CI: 1.10-1.66), and "Musculoskeletal and connective tissue disorders" (RR: 1.52; 95%CI: 1.11-2.07). In contrast, "Cardiac disorders" showed reduced likelihood in comparison with other disorders. For the time until post-approval addition of CSARs, "Skin and subcutaneous tissue disorders" showed the longest durations, with a median of 3020 days. CONCLUSIONS: Our quantitative analysis suggests that some CSARs were added more frequently to package inserts after approval and that time to post-approval additions of CSARs varied with the types of adverse drug reactions. These results can support the coherent implementation of pharmacovigilance activities.

Antipsychotic drugs and risk of idiopathic venous thromboembolism: a nested case-control study using the CPRD.

BACKGROUND: The evidence to date on the relationship between antipsychotic drugs and the risk of venous thromboembolism (VTE) is limited. PURPOSE: Our aim was to examine the association between the use of typical and atypical antipsychotics and risk of VTE and to assess the effects of dose and duration of use. METHODS: Among users of typical or atypical antipsychotics between 1998 and 2012 in the Clinical Practice Research Datalink, we identified all VTE cases aged 20-59 years with no major risk factors for VTE. From the same population, we randomly selected up to four controls for each case matched on age, sex, general practice, calendar time, and length of medical history. We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of VTE for current and recent use of antipsychotics compared with non-use using conditional logistic regression. RESULT: We identified 868 cases and 3158 matched controls. Compared with non-use, any current use of antipsychotics was associated with a marginally increased risk of VTE: aOR 1.26 (95%CI [0.97, 1.63]); for new users, the aOR was 3.21 (95%CI [1.64, 6.29]). Prochlorperazine and risperidone were associated with elevated risks of VTE (aORs 2.18, 95%CI [1.47, 3.25], and 1.83, 95%CI [0.88, 3.81], respectively). CONCLUSION: The risk of VTE with typical and atypical antipsychotics varies with type of drug and is highest just after starting the drug.

Continuous co-prescription of rebamipide prevents upper gastrointestinal bleeding in NSAID use for orthopaedic conditions: A nested case-control study using the LIFE Study database.

BACKGROUND: Rebamipide has been widely co-prescribed with non-steroidal anti-inflammatory drugs (NSAIDs) in Japan for decades. This study aimed to evaluate the effectiveness of rebamipide in preventing upper gastrointestinal bleeding in new users of NSAIDs without risk factors of NSAID-induced ulcers other than age. METHODS: A nested case-control study was conducted using medical claims data of 1.66 million inhabitants of 17 municipalities participating in Japan's Longevity Improvement & Fair Evidence study. The cohort entry (t0) corresponded to a new user of NSAIDs for osteoarthritis or low back pain. Patients with risk factors of NSAID-induced ulcers other than age were excluded. Cases were defined as patients who underwent gastroscopy for upper gastrointestinal bleeding (occurrence date was defined as index date). A maximum of 10 controls were selected from non-cases at the index date of each case by matching sex, age, follow-up time, and type and dosage of NSAIDs. Exposure to rebamipide was defined as prescription status from t0 to index date: Non-user (rebamipide was not co-prescribed during the follow-up period), Continuous-user (rebamipide was co-prescribed from t0 with the same number of tablets as NSAIDs), and Irregular-user (neither Non-user nor Continuous-user). Conditional logistic regression analysis was conducted to estimate each category's odds ratio compared to non-users. FINDINGS: Of 67,561 individuals who met the inclusion criteria, 215 cases and 1,516 controls were selected. Compared with that of Non-users, the odds ratios and 95% confidence interval were 0.65 (0.44-0.96) for Continuous-users and 2.57 (1.73-3.81) for Irregular-users. CONCLUSIONS: Continuous co-prescription of rebamipide significantly reduced the risk of upper gastrointestinal bleeding in an Asian cohort of new users of NSAIDs with osteoarthritis or low back pain without risk factors other than age.

Association between mRNA COVID-19 vaccine boosters and mortality in Japan: The VENUS study.

Although previous studies have shown no increased mortality risk after the primary series of COVID-19 mRNA vaccines, reports on booster doses are lacking. This study aimed to evaluate mortality risk after the mRNA vaccine boosters in addition to the primary series. This nested case-control study included two age-specific cohorts (18-64 and ≥65 years as of February 1, 2021) in two municipalities. All deaths were identified and matched five controls for each case at each date of death (index date) with risk set sampling according to municipality, age, and sex. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for mRNA vaccines (first to fifth doses) were estimated by comparing with no vaccination within 21 and 42 days before the index date using a conditional logistic regression model. The 18-64-years cohort comprised 431 cases (mean age, 57.0 years; men, 58.2%) and 2,155 controls (mean age, 56.0; men, 58.2%), whereas the ≥65-years cohort comprised 12,166 cases (84.0; 50.2%) and 60,830 controls (84.0, 50.2%). The aORs (95% CI) in 0-21 days after the third and fourth doses in the 18-64-years cohort were 0.62 (0.24, 1.62) and 0.38 (0.08, 1.84), respectively. The aORs (95% CI) after the third to fifth doses in the ≥65 years cohort were 0.36 (0.31, 0.43), 0.30 (0.25, 0.37), and 0.26 (0.20, 0.33), respectively. In conclusion, booster doses of mRNA vaccines do not increase mortality risk. These findings could help subsequent vaccine campaigns and alleviate vaccine hesitancy.

Risk of neutropenia in psoriasis patients prescribed anti-IL-23 antibody in comparison with anti-IL-17 antibody or adalimumab based on real-world data from the MID-NET® in Japan.

BACKGROUND: To evaluate the risk of neutropenia during treatment with anti-IL-23 antibodies in patients with psoriasis. METHOD: We conducted an observational study with cohort design using MID-NET® in Japan. We identified patients with psoriasis who were newly prescribed anti-IL-23 antibodies, anti-IL-17-antibodies, adalimumab, or apremilast between January 1, 2009, and March 31, 2021. We estimated the adjusted hazard ratio (aHR) of anti-IL-23 antibodies compared to that of anti-IL-17 antibodies, adalimumab, or apremilast, for the risk of grade 2 (neutrophil count < 1,500/µL) or grade 3 (neutrophil count < 1,000/µL) neutropenia. RESULTS: Overall, 287 patients on anti-IL-23 antibodies, 189 patients on anti-IL-17 antibodies, 293 patients on adalimumab, and 540 patients on apremilast were included. Compared with anti-IL-17 antibodies, the aHR (95% confidence interval (CI)) of anti-IL-23 antibodies was 0.83 (0.27-2.51) for grade 2 and 0.40 (0.02-7.60) for grade 3 neutropenia; that when compared with adalimumab was 0.76 (0.28-2.06) for grade 2 but was not calculated for grade 3 as no cases were found; and that compared with apremilast was 3.88 (0.62-24.48) for grade 2 and 0.43 (0.02-11.63) for grade 3 neutropenia. CONCLUSION: No clear increase in the risk of neutropenia with anti-IL-23 antibodies was observed.

Lower Risks of Gastrointestinal Perforation and Intestinal Obstruction in Patients with Atypical Antipsychotics in Comparison with Typical Antipsychotics Based on Real-World Data from the MID-NET® in Japan.

Intestinal perforation and obstruction are known to be one of the adverse events caused by antipsychotics; however, warning information on package inserts varies among antipsychotics. To investigate the risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics compared with those in patients prescribed typical antipsychotics, a nested case-control study was conducted utilizing real-world data from the MID-NET® medical information database in Japan. The study period spanned from January 1, 2009, to December 31, 2018. We found that the risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics were significantly lower than those in patients prescribed typical antipsychotics (adjusted odds ratio, 0.48; 95% confidence interval, 0.29-0.80). This finding was supported with prolonged periods for the exposure definition in the sensitivity analyses. In addition, no major differences in the risks of atypical antipsychotics, such as risperidone, quetiapine, olanzapine, and aripiprazole, were identified in this study. The safety profile regarding the lower risks of gastrointestinal perforation and intestinal obstruction in patients prescribed atypical antipsychotics should be considered when choosing antipsychotics in clinical practice in terms of the proper use of such drugs.

Descriptive Analysis for the Trend of Pharmacovigilance Planning in Risk Management Plans on New Drugs Approved During 2016-2019.

BACKGROUND: Japanese pharmaceutical authorities have conducted regulatory renovations of pharmacovigilance planning (PVP) since implementing new procedures for developing post-marketing study plans in 2018 in order to promote more focused and scientific approaches. This study aimed to descriptively assess the effects of those regulatory renovations on PVP for new drugs in Japan. METHODS: We identified PVP information (drug characteristics, efficacy and safety issues, and additional activities) from the first version of risk management plans for new drugs approved between 2016 and 2019. The following indicators were analyzed: (1) proportion of the number of drugs with at least one efficacy issue among all the drugs, (2) proportion of the number of safety issues with additional activity among all the safety issues, and (3) proportion of database studies among all additional activities. RESULTS: In total, 168 drugs, 1212 safety issues, and 301 additional activities were identified. The proportion of drugs with at least one efficacy issue decreased from 91.4% in 2016 to 27.3% in 2019, and the proportion of safety issues with additional activity also decreased from 93.9% in 2016 to 53.7% in 2019. In contrast, the proportion of database studies increased from 0 to 19.2%. The percentages of additional activities targeting important identified and potential risks also gradually decreased during the 4-year period. CONCLUSION: Notable changes in the three indicators during 2016-2019 were observed, which suggests that regulatory renovation has affected PVP in Japan.

Multiregional Population-Based Cohort Study for Evaluation of the Association Between Herpes Zoster and mRNA Vaccinations for Severe Acute Respiratory Syndrome Coronavirus-2: The VENUS Study.

Background: This study was performed to assess the increased risk of herpes zoster (HZ) associated with mRNA vaccines for coronavirus disease 2019. Methods: This population-based cohort study was conducted in 4 municipalities in Japan. Individuals covered under public health insurance systems without a history of HZ were followed from October 1, 2020 to November 30, 2021. Incidence rates of HZ within 28 days of BNT162b2 or mRNA-1273 vaccination were compared. Adjusted incidence rate ratios (IRR) and 95% confidence intervals (CI) were estimated using a Poisson regression model, including vaccination status as a time-dependent covariate. Subgroup analyses by sex, age, and municipality were also conducted. Results: A total of 339 548 individuals (median age, 74 years) were identified. During follow up, 296 242 individuals (87.2%) completed the primary series, among whom 289 213 and 7019 individuals received homologous BNT162b2 and mRNA-1273 vaccines, respectively. The adjusted IRRs of the first and second BNT162b2 vaccinations were 1.05 (95% CI, 0.84-1.32) and 1.09 (95% CI, 0.90-1.32), respectively. No cases of HZ were observed after mRNA-1273 vaccination. In subgroup analysis, the adjusted IRR of the second BNT162b2 vaccination was 2.94 (95% CI, 1.41-6.13) in individuals aged <50 years old. Conclusions: No increased risk of HZ was found after BNT162b2 vaccination in the overall study population. However, an increased risk was observed in the younger subgroup.

Bivalent Vaccine Effectiveness Among Adults Aged ≥65 Years During the BA.5-Predominant Period in Japan: The VENUS Study.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.5 became prevalent in July 2022 in Japan. Bivalent messenger RNA (mRNA) vaccines were approved as booster doses for individuals who received the primary series or booster dose by monovalent vaccines. We aimed to assess the effectiveness of bivalent vaccines in Japanese adults aged ≥65 years. Methods: We conducted a population-based cohort study using data collected from January 2019 to February 2023 in Japan. We included individuals aged ≥65 years in a municipality who received the first or second booster dose of monovalent mRNA vaccines. We estimated the effectiveness of the second or third booster dose of bivalent mRNA vaccines during the Omicron BA.5-predominant period (July-December 2022), compared with ≥90 days after the booster dose of monovalent vaccines. We used a Cox proportional hazard regression model with vaccination status as a time-dependent covariate. Results: A total of 81 977 individuals aged ≥65 years (mean [standard deviation] age, 78.3 [7.4] years; 33 487 male [40.8%]) were included in the study cohort. Among them, 57 396 were vaccinated with the second or third dose of bivalent vaccines (BA.1 or BA.4/5). The effectiveness against coronavirus disease 2019 (COVID-19) was estimated to be 57.9% (95% confidence interval, 52.7%-62.5%) for ≥14 days after the second or third bivalent booster dose, compared with 90 days after the first or second monovalent booster dose. Conclusions: The study showed that the bivalent mRNA vaccines as the second and third doses would provide protection against COVID-19 among adults ≥65 years in Japan.

Characterizing Granulocytopenia Associated with Thiamazole in Patients with Hyperthyroidism Based on Real-World Data from the MID-NET in Japan.

Despite the requirement of routine blood tests during thiamazole treatment in Japan, granulocytopenia among patients treated with thiamazole has been occasionally reported to the Pharmaceuticals and Medical Devices Agency (PMDA). To characterize granulocytopenia in patients with thiamazole in Japan, the effects of routine blood tests were examined in a cohort of new users of thiamazole or propylthiouracil utilizing the MID-NET. The occurrence of granulocytopenia (neutrophil count ≤ 1,500/µL) in a given period was compared between patients with and without blood test results prior to the period. The trend in neutrophil count during thiamazole treatment was also compared between patients with and without granulocytopenia. A nested case-control study based on the cohort was conducted to identify potential risk factors for granulocytopenia during thiamazole treatment. In the new user cohort including 4,371 patients treated with thiamazole, the occurrence of granulocytopenia in patients who had undergone blood tests at all previous periods was similar or higher than that among those who had not undergone blood test in all previous periods (e.g., adjusted odds ratio in period 2 was 1.63). The neutrophil count was relatively lower in the group of patients with granulocytopenia even before the occurrence of granulocytopenia. In a nested case-control study, an upward tendency of the risk was observed when a patient was co-prescribed anti-arrhythmic drugs or antiulcer drugs with thiamazole. The characteristics of granulocytopenia during thiamazole treatment elucidated in this study should be recognized in clinical practice for the proper use of thiamazole.

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.

Use of National Database of Health Insurance Claims and Specific Health Checkups for examining practical utilization and safety signal of a drug to support regulatory assessment on postmarketing drug safety in Japan.

The Pharmaceuticals and Medical Devices Agency (PMDA) has conducted many pharmacoepidemiological studies for postmarketing drug safety assessments based on real-world data from medical information databases. One of these databases is the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), containing health insurance claims of almost all Japanese individuals (over 100 million) since April 2009. This article describes the PMDA's regulatory experiences in utilizing the NDB for postmarketing drug safety assessment, especially focusing on the recent cases of use of the NDB to examine the practical utilization and safety signal of a drug. The studies helped support regulatory decision-making for postmarketing drug safety, such as considering a revision of prescribing information of a drug, confirming the appropriateness of safety measures, and checking safety signals in real-world situations. Different characteristics between the NDB and the MID-NET® (another database in Japan) were also discussed for appropriate selection of data source for drug safety assessment. Accumulated experiences of pharmacoepidemiological studies based on real-world data for postmarketing drug safety assessment will contribute to evolving regulatory decision-making based on real-world data in Japan.