Context and Considerations for Use of Two Japanese Real-World Databases in Japan: Medical Data Vision and Japanese Medical Data Center

Treatment patterns and clinical outcomes in patients with metastatic triple-negative breast cancer: a large-scale data analysis using the Japanese claims database

PURPOSE

This study evaluated treatment patterns and clinical outcomes among patients with metastatic triple-negative breast cancer (mTNBC) in real-world clinical settings in Japan.

METHODS

The treatment patterns, time to next treatment or death (TTNTD), time to treatment discontinuation, adverse events of interest, and medical costs of treating patients with mTNBC in first-, second-, and third-line settings were investigated using data of patients meeting the inclusion criteria between January 2017 and March 2022 in a Japanese medical claims database. The treatment regimens for mTNBC were defined according to the Japanese Breast Cancer Society Clinical Practice Guidelines.

RESULTS

In this study, 2236 patients with mTNBC (median age 66.0 years; 99.8% female) were included in the first-line cohort. Of these, 46.6% and 20.8% were included in the second- and third-line cohorts, respectively. The two most frequently used treatments were capecitabine (19.1%) and S-1 (tegafur-gimeracil-oteracil) (14.5%) in the first-line cohort, eribulin (18.3%) and bevacizumab/paclitaxel (14.4%) in the second-line cohort, and eribulin (19.4%) and bevacizumab/paclitaxel (17.5%) in the third-line cohort. The TTNTD shortened as the line of therapy progressed (median 8.0, 6.5, and 5.2 months for the first-, second-, and third-line treatments, respectively). Nausea/vomiting and neutropenia/leukopenia occurred in 62.8% and 18.3% of all patients, respectively. The medical total costs per day were 6.7, 10.2, and 12.9 thousand yen during the first-/second-/third-line treatments, respectively.

CONCLUSION

This study provides insight into current treatment patterns for mTNBC in Japan. The cost-benefit balance worsens with later-line treatment and a high unmet need for mTNBC drug treatment remains.

Maintained renin-angiotensin-aldosterone system inhibitor therapy with sodium zirconium cyclosilicate following a hyperkalaemia episode: a multicountry cohort study

Background

This observational cohort study compared the likelihood of maintained (stabilized/up-titrated) renin-angiotensin-aldosterone system inhibitor (RAASi) therapy at 6 months following hyperkalaemia in patients with chronic kidney disease (CKD) and/or heart failure (HF) from the USA, Japan and Spain who received sodium zirconium cyclosilicate (SZC) for at least 120 days, relative to those with no prescription for a potassium (K+) binder.

Methods

Using health registers and hospital medical records, patients with CKD and/or HF receiving RAASi therapy who experienced a hyperkalaemia episode were identified. Propensity score (PS) matching (1:4) was applied to balance the SZC cohort to the no K+ binder cohort on baseline characteristics. Logistic regression analysis was performed to compare the odds of maintained RAASi therapy at 6 months in the SZC versus no K+ binder cohorts.

Results

The PS-matched SZC cohort included 565 (USA), 776 (Japan) and 56 (Spain) patients; the no K+ binder cohort included 2068, 2629 and 203 patients, respectively. At 6 months, 68.9% (USA), 79.9% (Japan) and 69.6% (Spain) in the SZC cohorts versus 53.1% (USA), 56.0% (Japan) and 48.3% (Spain) in the no K+ binder cohorts had maintained RAASi therapy. Meta-analysed across countries, the odds ratio of maintained RAASi therapy in the SZC cohort versus no K+ binder cohort was 2.56 (95% confidence interval 1.92-3.41; P < .0001).

Conclusions

In routine clinical practice across three countries, patients treated with SZC were substantially more likely to maintain guideline-concordant RAASi therapy at 6 months following hyperkalaemia relative to patients with no K+ binder treatment.

Real-world data of HER2-negative early breast cancer patients treated with anthracycline and/or taxane regimens in Japan

BACKGROUND

Anthracycline- and taxane-based chemotherapy regimens are established treatments for human epidermal growth factor receptor (HER)2-negative early-stage breast cancer with high risk of recurrence. This study examined the prevalence of these chemotherapy regimens as perioperative therapy, the patterns of retreatment, and factors influencing prescription choices in Japan.

METHODS

This observational cohort study focused on high-risk early-stage breast cancer patients not undergoing anti-HER2 therapy, utilizing data from a hospital-based claims database in Japan spanning from April 2008 to September 2021.

RESULTS

Of 42,636 high-risk patients who underwent breast cancer surgery, 32,133 (75.4%) were categorized as having luminal-type (received endocrine therapy) and 10,503 (24.6%) as having triple-negative cancer (not receiving any endocrine therapies). Most patients (98.7%) with luminal-type breast cancer received perioperative therapy, and 40.3% of those received anthracycline/taxane. In the triple-negative group, 57.0% of all patients received perioperative therapy and of those, 93.4% received anthracycline/taxane. Being over 40 years old, having an early stage (clinical stage ≤ II), and receiving treatment in non-specialized facilities were associated with less use of anthracycline/taxane in the luminal-type group. For the triple-negative group, associated factors with less use of anthracycline/taxane included being over 60 years old, treatment in small hospital (capacity < 200 beds), and treatment in non-specialized facilities.

CONCLUSIONS

Approximately half the patients in both the luminal-type and triple-negative groups were prescribed anthracycline and/or taxane for perioperative chemotherapy. The choice was associated with patient age, cancer stage, and the scale and specialization of the treatment facilities. This study sheds light on the current state of breast cancer treatment practices in Japan.

Development and validation of a machine learning model to predict postoperative delirium using a nationwide database: A retrospective, observational study

STUDY OBJECTIVE

Postoperative delirium is a neuropsychological syndrome that typically occurs in surgical patients. Its onset can lead to prolonged hospitalization as well as increased morbidity and mortality. Therefore, it is important to promptly identify its signs. This study aimed to develop and validate a machine learning predictive model for postoperative delirium using extensive population data.

DESIGN

Retrospective observational study.

SETTING

Japanese Diagnosis Procedure Combination inpatient data. Data were used for internal (2016.4-2018.12) and temporal validation (2019.01-2019.10).

PATIENTS

Patients aged ≥65 years who underwent general anesthesia for surgical procedure.

MEASUREMENTS

The primary outcome was postoperative delirium, which was defined as a condition requiring newly prescribed antipsychotic drugs or assignment of the corresponding insurance claim code after the date of surgery. We trained and tuned the optimal machine-learning model through 10-fold cross-validation using the selected optimal area under the receiver operating characteristic curve (AUC) value. In the temporal validation, we measured the performance of our model.

MAIN RESULTS

The analysis included 557,990 patients. The light-gradient boosting machine models showed a higher AUC value (0.826 [95% confidence interval (CI): 0.822-0.829]) than the other models. Regarding performance, the model had a recall value of 0.124 (95% CI: 0.119-0.129) and precision value of 0.659 (95% CI: 0.641-0.677]). This performance was sustained in the temporal validation (AUC, 0.815 [95% CI: 0.811-0.818]). At a sensitivity of 0.80, the model achieved a specificity of 0.672 (95% CI: 0.670-0.674]), a negative predictive value of 0.975 (95% CI: 0.974-0.975), and a positive predictive value of 0.176 (95% CI: 0.176-0.179).

CONCLUSIONS

Using extensive Diagnostic Procedure Combination data, we successfully created and validated a machine learning model for predicting postoperative delirium. This model may facilitate prediction of postoperative delirium.

Association Between Arterial Pulse Waveform Analysis and Mortality in Patients With Septic Shock: A Retrospective Cohort Study Using Japanese Diagnosis Procedure Combination Data

Purpose: Specialized pressure transducers for arterial pulse waveform analysis (S-APWA) devices are dedicated kits connected to an arterial pressure catheter that monitors hemodynamic parameters, such as cardiac output, pulse pressure variation, and stroke volume variation, less invasively. While the association between the use of S-APWA devices and clinical outcomes in perioperative patients has been previously evaluated, its assessment in patients with septic shock remains inadequate. Materials and Methods: This retrospective cohort study utilized a nationwide Diagnosis Procedure Combination database in Japan. Adult patients with septic shock admitted to the intensive care unit (ICU) with arterial pressure catheter placement on the admission day from August 2012 to February 2021 were included. Hospitalizations meeting the eligibility criteria were categorized into groups based on S-APWA device usage. The primary outcome, evaluated using Cox regression analysis, was 30-day all-cause mortality in the propensity score overlap-weighted population. Secondary outcomes included in-hospital mortality, ICU duration, and overall hospital stay. Results: Among 5130 eligible hospitalizations, 643 were in the S-APWA group and 4487 were in the conventional pressure transducer group. Cox regression analysis within the propensity score overlap-weighted population showed no significant difference in 30-day mortality (adjusted hazard ratio: 0.94; 95% confidence interval: 0.9-1.38; P = .58). Logistic regression analysis indicated no significant differences in the in-hospital mortality. While the S-APWA group had prolonged ICU stays, no significant difference in the overall hospital stay was observed according to linear regression analyses. Conclusions: Our study found no significant association between S-APWA use and 30-day mortality in patients with septic shock. These findings offer insights into optimizing monitoring systems in ICUs.

Effect of cancer cachexia on first-line chemotherapy in patients with advanced pancreatic cancer: a claims database study in Japan

BACKGROUND

Cancer cachexia is a multifactorial syndrome leading to progressive functional impairment. How cachexia affects the treatment course of chemotherapy in patients with pancreatic cancer has not been well understood.

METHODS

This is an exploratory, retrospective, observational cohort study using the Japanese medical claims database from Medical Data Vision Co., Ltd. The study population included patients diagnosed with pancreatic cancer in whom first-line FOLFIRINOX (FFX) or gemcitabine plus nab-paclitaxel (GnP) was initiated between October 1, 2018, and September 30, 2020. In this study, we defined patients with cancer cachexia as those who had a weight loss of ≥ 5% in the preceding 6 months. The primary outcome was time-to-treatment failure (TTF). The observation period was six months from the initiation of first-line FFX or GnP treatment.

RESULTS

A total of 1897 patients (421 patients into the cachexia group; 1476 patients into the non-cachexia group) were analyzed in this study. The median TTF was 121 days (95% confidence interval [CI] 94-146) in the cachexia group and 143 days (95% CI 134-152) in the non-cachexia group. The hazard ratio for TTF of the cachexia versus non-cachexia group was 1.136 (95% CI 0.979-1.319). The median number of doses was two doses fewer in the cachexia group than in the non-cachexia group for both FFX and GnP.

CONCLUSION

Cancer cachexia was suggested to be associated with shorter TTF and a reduced number of doses in patients with pancreatic cancer who received first-line FFX or GnP treatment. Clinical Trial Registration clinicaltrials.jp: UMIN000045820.

Real-world diagnostic landscape and incidence of pulmonary hypertension in adult congenital heart disease patients using administrative claims data in Japan

BACKGROUND

Although pulmonary hypertension (PH) and Eisenmenger's syndrome (ES) are common complications in adult congenital heart disease (ACHD), the frequency of diagnostic tests and the incidence of PH/ES in patients with ACHD in Japanese clinical practice are unclear. Therefore, we sought to clarify the frequency of diagnostic tests and incidence of PH/ES in patients with ACHD using the Medical Data Vision (MDV) database, the largest anonymized database of diagnosis procedure combination hospitals in Japan.

METHODS

We conducted a retrospective cohort study using the MDV database (April 2008 to December 2021) of patients with ACHD (International Classificaiton of Diseases, 10th revision codes: Q203-204, Q210-213, Q250) aged ≥15 years. The frequency of laboratory/clinical tests and the incidence of PH/ES were calculated. Subgroup analyses were performed for the periods 2008-2015 and 2016-2021.

RESULTS

Overall, 28219 ACHD patients were extracted from the MDV database (females 56.3%, males 43.7%; mean ± standard deviation age 44.7 ± 23.5 years). The mean ± standard deviation follow-up period was 2.5 ± 2.7 years. The frequencies of electrocardiography, ultrasonography, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP), right heart catheterization, and pulmonary function tests (DLCO) were 2149.8, 1054, 1233, 340, 40.0, and 6.0 per 1000 person-years, respectively. The incidence rate of PH/ES was 32.8 per 1000 person-years. The incidence rate of PH/ES increased from 24.6 to 46.7 per 1000 person-years from 2008-2015 to 2016-2021.

CONCLUSION

We have clarified the frequency of diagnostic tests related to PH/ES and the incidence of PH/ES in patients with ACHD in clinical practice in Japan, including non-specialist institutions for PH.

Real-World Clinical Profile of Patients Prescribed Evolocumab in Japan

BACKGROUND

Real-world utilization data for evolocumab, the first proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to be introduced in Japan in 2016, to date are limited. This study aimed to clarify the current real-world patient user profiles of evolocumab based on large-scale health claims data.Methods and Results: This retrospective database study examined patients from a health administrative database (MDV database) who initiated evolocumab between April 2016 (baseline) and November 2021. Characteristics and clinical profiles of this patient population are described. In all, 4,022 patients were included in the final analysis. Most evolocumab prescriptions occurred in the outpatient setting (3,170; 78.82%), and 940 patients (23.37%) had a recent diagnosis of familial hypercholesterolemia. Common recent atherosclerotic cardiovascular disease events at baseline included myocardial infarction (1,633; 40.60%), unstable angina (561; 13.95%), and ischemic stroke (408; 10.14%). Comorbidity diseases included hypertension (2,504; 62.26%), heart failure (1,750; 43.51%), diabetes (1,199; 29.81%), and chronic kidney disease (297; 7.38%). Among the lipid-lowering regimens concomitant with evolocumab, ezetimibe+statin was used most frequently (1,281; 31.85%), followed by no concomitant lipid-lowering regimen (1,190; 29.59%), statin (950; 23.62%), and ezetimibe (601; 14.94%). The median evolocumab treatment duration for all patients was 260 days (interquartile range 57-575 days).

CONCLUSIONS

This study provides real-world insights into evolocumab utilization in Japan for optimizing patient care and adherence to guideline-based therapies to better address hypercholesterolemia in Japan.

Lack of Association Between Immunotherapy and Improvement of Survival for Non-small Cell Lung Cancer Patients With Hemodialysis: A Nationwide Retrospective Cohort Study

BACKGROUND

The number of patients undergoing hemodialysis continues to increase globally, and the incidence of cancer is high among these patients. Immune checkpoint inhibitors are widely used in patients with advanced cancer, especially non-small cell lung cancer (NSCLC); however, their effectiveness in hemodialysis patients is poorly documented.

METHODS

This retrospective cohort study used data from a nationwide database. Patients diagnosed with NSCLC, undergoing hemodialysis, and who started chemotherapy between September 2008 and January 2023 were included. In the intention to treat (ITT) analysis, patients were divided into immune checkpoint inhibitor (ICI) and conventional chemotherapy group, and in the chronological analysis, patients were divided into 2 groups before and after ICI approval. Overall survival (OS) was analyzed using the Kaplan-Meier method with log-rank tests and Cox proportional hazards analyses. A propensity score approach was applied to address confounding factors, and analyses were performed by weighting each patient with the inverse of the estimated propensity score.

RESULTS

We identified 322 and 389 patients in the ITT and chronological analyses respectively. In both analyses, there were no notable difference of OS between 2 groups (P values by log-rank test 0.933 and 0.248, respectively). The hazard ratios for OS were 0.980 (95% confidence interval [CI]: 0.678-1.415) in the ITT analysis and 0.805 (95% CI: 0.531-1.219) in the chronological analysis.

CONCLUSION

The ICI treatment and approval were not significantly associated with improvement of survival in patients with NSCLC undergoing hemodialysis.

Clinical Practice Patterns and Risk Factors for Severe Conditions in Pediatric Hospitalizations With Respiratory Syncytial Virus in Japan: A Nationwide Analyses (2018-2022)

BACKGROUND

Respiratory syncytial virus (RSV) represents a global health challenge, especially among younger children. While the disease burden in Japan has been preliminarily quantified, there remains a lack of comprehensive understanding regarding treatment patterns and the influence of known risk factors at a national scale.

MATERIALS AND METHODS

We conducted a retrospective cohort study consisting of 50,482 children under 5 years hospitalized with RSV infections during 2018-2022 using the Medical Data Vision database. We investigated trends in patient characteristics, health resource use, treatment patterns, and laboratory data. Additionally, multivariable modified Poisson regression models were used to investigate the risk factors associated with severe conditions.

RESULTS

We observed an increasing trend in the inpatient healthcare costs and decreasing trends in the use of antibiotics, bronchodilators, systemic corticosteroids and other symptomatic medications from 2018 to 2022. Risk factors associated with severe RSV infections were children less than 1 year (risk ratio, 2.90; 95% CI: 2.53-3.32) and the number of complex chronic diseases (risk ratio for 1 disease, 2.68; 95% CI: 2.34-3.06: risk ratio for 2 or more diseases, 6.91; 95% CI: 5.81-8.21). Annual inpatient healthcare costs for RSV infections were estimated at 11-14 billion Japanese Yen for younger children.

CONCLUSIONS

Our study observed the changes in practice patterns and health resource use for children hospitalized with RSV infections and identified risk factors associated with severe conditions. These findings provide insights for policymakers and clinicians aiming to devise strategies for further improving clinical practices, including newly developed vaccines and single-dose long-acting monoclonal antibodies.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Burden of narcolepsy in Japan: A health claims database study evaluating direct medical costs and comorbidities

OBJECTIVE

This study aimed to determine the burden of narcolepsy in terms of direct medical costs and comorbidities and compare it with the respective burden of schizophrenia, epilepsy, and ulcerative colitis as controls.

METHODS

Patients diagnosed with narcolepsy (at least once based on the International Statistical Classification of Diseases and Related Health Problems, 10th Revision, code G47.4) between April 2017 and March 2022 were identified on the health insurance claims database compiled by JMDC Inc. Patients with schizophrenia (F20), epilepsy (G40), and ulcerative colitis (K51) were matched as controls. Direct medical costs (including inpatient, outpatient, and medication costs) and comorbidities were analyzed.

RESULTS

We identified 4,594 patients with narcolepsy (≥18 years), 18,376 with schizophrenia, 18,376 with epilepsy, and 4,594 with ulcerative colitis. The total annual direct medical cost per person with narcolepsy was 349,188 JPY. The cost for narcolepsy was less than that for schizophrenia, epilepsy, and ulcerative colitis. Several comorbidities, such as sleep apnea, attention deficit hyperactivity disorder (ADHD), and obesity were more prevalent in the narcolepsy group.

CONCLUSIONS

The total direct cost for narcolepsy was approximately three times higher than the national medical expense for people aged 15-44 years (122,000 JPY in 2020), but lower than the total cost for all control diseases. The patients with narcolepsy were also likely to have comorbidities that affected their burden. These findings can contribute to future discussions on medical expense assistance programs for patients with narcolepsy.

Clinical Practice Patterns, Health Resource Use and Risk Factors for Severe Conditions Among Children Hospitalized With COVID-19 in Japan

BACKGROUND

The trends in clinical practice patterns and health resource use, as well as risk factors for severe conditions among children hospitalized with coronavirus disease-2019 (COVID-19), remain unclear.

MATERIALS AND METHODS

We conducted a retrospective observational study consisting of 9876 children hospitalized with COVID-19 during 2020-2022 using the Medical Data Vision database in Japan. We investigated trends in patient characteristics, health resource use, treatment patterns and laboratory data. Additionally, log-binomial regression models were used to investigate the risk factors associated with severe COVID-19 among pediatric inpatients with COVID-19.

RESULTS

We observed decreasing trends in the lengths of hospital stays, healthcare costs, computed tomography use, and antibiotic use, and increasing trends in treatment with intravenous hydration and use of antipyretics, antiepileptics, antiemetics and antivirals from the first wave to the seventh wave of COVID-19 pandemic. During the 3-year period, the risk of severe COVID-19 was almost stable at 3%. Risk factors associated with severe COVID-19 were children less than 1 year old [risk ratio (RR): 1.69; 95% confidence interval (CI): 1.02-2.78], the number of complex chronic diseases (RR for 1 disease: 4.49; 95% CI: 2.76-7.32; RR for 2 or more diseases: 10.2; 95% CI: 5.19-20.3) and asthma (RR: 1.84; 95% CI: 1.06-3.20).

CONCLUSIONS

Our study observed the changes in practice patterns and health resource use for children hospitalized with COVID-19 and identified risk factors associated with severe COVID-19. These findings indicate the importance of vigilant monitoring and tailored treatment strategies in children with these risk factors.

Immune Checkpoint Inhibitor Is Associated with Improved Survival in Advanced Non-small Cell Lung Cancer Occurring in Patients with Autoimmune Disease

The use of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). However, clinical trials often exclude those with a history of autoimmune diseases (ADs) because of concerns regarding immune-related adverse events. Therefore, the efficacy of ICIs in advanced NSCLC patients with ADs should be evaluated. This study used administrative claims data from advanced treatment centers in Japan and identified patients with advanced NSCLC who began chemotherapy between December 2016 and January 2023. The patients were divided into four groups based on the presence of ADs and types of chemotherapy received. The association between ICI therapy and overall survival in the subgroups with or without ADs, and the association between the presence of AD and overall survival in patients who received ICI therapy and conventional chemotherapy, were analyzed using Cox proportional hazard regression, including therapy and presence of ADs and their interaction as covariates. These results were obtained using the inverse probability of treatment weighting. ICI therapy had a hazard ratio (95% confidence interval) for death in the subgroup of AD and non-AD patients of 0.88 (0.84-0.92) and 0.83 (0.71-0.97), respectively (p = 0.459 for interaction). For some specific ADs, including type 1 diabetes mellitus, the association between ICI therapy and decreased mortality was not observed. In conclusion, our study showed comparable associations between ICI therapy and reduced mortality in AD and non-AD subgroups of patients with advanced NSCLC. However, therapy strategies tailored to each AD type and thorough discussions regarding the risk-benefit profile are crucial.

Clinical features of acute attacks, chronic symptoms, and long-term complications among patients with acute hepatic porphyria in Japan: a real-world claims database study

BACKGROUND

Acute hepatic porphyria (AHP) is a family of rare genetic diseases, including acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and delta-aminolevulinic acid dehydratase-deficient porphyria. The objective of this retrospective cohort study was to provide information on the clinical features of AHP in Japan-including acute attacks, chronic symptoms, and long-term complications.

METHODS

Patients with AHP between April 2008 and June 2020 were selected from Japan's Medical Data Vision claims database. Patients with AHP were matched 1:10, by sex and age, to patients without AHP. The outcomes were evaluated overall, for patients age ≥ 55 years, and for the matched population.

RESULTS

A total of 391 patients with AHP were included from the Japanese Medical Data Vision database. During the observation period (April 2008-June 2020), 18.2% (71/391) of patients experienced 1 acute attack and 10.5% (41/391) experienced ≥ 2 attacks. Chronic symptoms with rates ~ 10% or higher in the AHP population compared with the matched population included neurotic, stress-related, and somatoform disorders (21.7% vs. 6.7% [15.0% difference]); sleep disorders (23.0% vs. 9.9% [13.1% difference]); other and unspecified abdominal pain (13.6% vs. 3.7% [9.9% difference]); and nausea and vomiting, excluding chemotherapy-induced emesis (17.9% vs. 8.1% [9.8% difference]). Long-term complications with higher incidence rates in the AHP population compared with the matched population included fibrosis and cirrhosis of liver (15.9% vs. 3.0% [12.9% difference]), polyneuropathies and other disorders of the peripheral nervous system (20.5% vs. 7.9% [12.6% difference]), liver cancer (16.9% vs. 4.7% [12.2% difference]), renal failure (16.4% vs. 4.3% [12.1% difference]), and hypertension (26.1% vs. 18.8% [7.3% difference]). Among AHP patients age ≥ 55 years, the most common long-term complications were hypertension, kidney failure, and liver cancer.

CONCLUSIONS

In Japan, patients with AHP experience a high clinical burden in terms of acute attacks, chronic symptoms, and long-term complications. The clinical burden related to chronic symptoms and long-term complications was substantially higher in Japanese patients with AHP compared with a matched population without AHP. Recognizing these signs and symptoms of AHP may aid physicians in making an earlier diagnosis, which may help patients avoid attack triggers, implement disease management, and reduce lifetime disease burden.

Benefit of Prompt Vs Delayed Initiation of Triple Therapy Following an Exacerbation in Patients with COPD in Japan: A Retrospective Cohort Study

Purpose

There is currently limited evidence for the optimal timing of triple therapy initiation in Japan, which is crucial for optimizing strategies for the effective treatment of chronic obstructive pulmonary disease (COPD). This study assessed the impact of prompt vs delayed initiation of triple therapy following a COPD exacerbation on clinical and economic outcomes in patients in Japan.

Patients and Methods

Retrospective cohort study of patients in the Medical Data Vision Co., Ltd. database initiating triple therapy as single-inhaler triple therapy (fluticasone furoate/umeclidinium/vilanterol or budesonide/glycopyrronium/formoterol) or multiple-inhaler triple therapy within 180 days of a moderate-to-severe exacerbation (index). For the main analysis, patients were categorized as prompt or delayed initiators, initiating triple therapy within 0-30 days or 31-180 days of index, respectively. Inverse probability of treatment weighting based on propensity scores was used to adjust for measured confounders between prompt and delayed cohorts.

Results

For the main analysis, 610 (60.3%) and 402 (39.7%) patients were prompt and delayed initiators, respectively. The rate of subsequent moderate-to-severe exacerbations following index exacerbation was numerically lower in prompt vs delayed initiators (weighted rate ratio 0.95, 95% confidence interval [CI]: 0.74-1.21; P = 0.6603). Time-to-first subsequent moderate-to-severe exacerbation increased significantly in prompt vs delayed initiators (weighted hazard ratio 0.77, 95% CI: 0.64-0.93; P = 0.0053). In patients indexed on a severe exacerbation, delayed initiation resulted in significantly higher 90-day all-cause readmissions vs prompt initiation (42.1% vs 30.6%; P = 0.0329 [weighted estimates]). Weighted healthcare resource utilization rates were numerically lower in prompt vs delayed initiators, and weighted direct costs (all cause and COPD-related) were significantly lower in prompt initiators.

Conclusion

This real-world study demonstrated that earlier initiation of triple therapy resulted in several benefits in clinical outcomes for COPD and may also reduce the economic burden of COPD management in Japan.

Achievement Rates for Low-Density Lipoprotein Cholesterol Goals in Patients at High Risk of Atherosclerotic Cardiovascular Disease in a Real-World Setting in Japan

AIMS

The study aimed to investigate low-density lipoprotein cholesterol (LDL-C) goal achievement rates in patients receiving LDL-C-lowering therapy using recent real-world data, following the 2017 revision of the Japan Atherosclerosis Society Guidelines for Prevention of Atherosclerotic Cardiovascular Diseases (JAS GL2017).

METHODS

Patients with documented LDL-C test results were extracted from the Medical Data Vision claims database between July 2018 and June 2021 and divided into three groups according to JAS GL2017: primary prevention high risk (Group I, LDL-C goal ＜120 mg/dL), secondary prevention (Group II, LDL-C goal ＜100 mg/dL), and secondary prevention high risk (Group III, LDL-C goal ＜70 mg/dL).

RESULTS

The mean LDL-C value was 108.7 mg/dL (n=125,235), 94.4 mg/dL (n=57,910), and 90.6 mg/dL (n=33,850) in Groups I, II, and III, respectively. Intensive statin monotherapy (pitavastatin, rosuvastatin, or atorvastatin) was the most frequently prescribed lipid-lowering treatment (21.6%, 30.8%, and 42.7% in Groups I, II, and III, respectively), followed by ezetimibe (2.5%, 7.1%, and 8.5% in Groups I, II, and III, respectively). LDL-C goals were achieved by 65.5%, 60.6%, and 25.4% of patients overall in Groups I, II, and III, respectively. Achievement rates were 83.9%, 75.3%, and 29.5% in patients prescribed intensive statin monotherapy and 82.3%, 86.4%, and 46.4% in those prescribed statin and ezetimibe combinations in Groups I, II, and III, respectively. In Group III, the proportion of patients with familial hypercholesterolemia prescribed statin and ezetimibe combinations achieving LDL-C goals was low (32.5%).

CONCLUSIONS

The proportion of patients achieving LDL-C goals for secondary prevention in the high-risk group remains low even with statin and ezetimibe combination therapy.

In-Hospital Outcomes of Heart Failure Patients with Valvular Heart Disease: Insights from Real-World Claims Data

Purpose

Heart failure (HF) is a serious public health burden that is rapidly increasing in the aging population. Valvular heart disease (VHD) is a known etiology of heart failure (HF); however, the impact of VHD on outcomes of patients with HF has not been well-studied in Japan. This study aimed to determine the rates of VHD in Japanese patients admitted for HF and explore associations of VHD with in-hospital outcomes through a claim-based analysis.

Patients and methods

We analyzed claims data from 86,763 HF hospitalizations (January 2017 through December 2019) from the Medical Data Vision database. Common etiologies of HF were examined, then hospitalizations were categorized into those with VHD and those without. Covariate-adjusted models were used to explore the association of VHD with in-hospital mortality, length of stay, and medical cost.

Results

Of 86,763 hospitalizations for HF, 13,183 had VHD and 73,580 did not. VHD was the second most frequent etiology of HF (15.2%). The most frequent type of VHD was mitral regurgitation (36.4% of all hospitalizations with VHD), followed by aortic stenosis (33.7%) and aortic regurgitation (16.4%). There was no significant difference in in-hospital mortality between hospitalizations with VHD vs those without (9.0% vs 8.9%; odds ratio [95% CI]: 1.01 [0.95-1.08]; p=0.723). Hospitalizations with VHD were associated with significantly longer length of stay (26.1 vs 24.8 days; incident rate ratio [95% CI]: 1.05 [1.03-1.07]; p<0.001) and higher medical costs (1536 vs 1195 thousand yen; rate ratio [95% CI]: 1.29 [1.25-1.32]; p<0.001).

Conclusion

VHD was a frequent etiology of HF that was associated with significant medical resource use. Future studies are needed to investigate whether timely VHD treatment could reduce HF progression and its associated healthcare resource utilization.

Strategies to Address Current Challenges in Real-World Evidence Generation in Japan

The generation of real-world evidence (RWE), which describes patient characteristics or treatment patterns using real-world data (RWD), is rapidly growing more popular as a tool for decision-making in Japan. The aim of this review was to summarize challenges to RWE generation in Japan related to pharmacoepidemiology, and to propose strategies to address some of these challenges. We first focused on data-related issues, including the lack of transparency of RWD sources, linkage across different care settings, definitions of clinical outcomes, and the overall assessment framework of RWD when used for research purposes. Next the study reviewed methodology-related challenges. As lack of design transparency impairs study reproducibility, transparent reporting of study design is critical for stakeholders. For this review, we considered different sources of biases and time-varying confounding, along with potential study design and methodological solutions. Additionally, the implementation of robust assessment of definition uncertainty, misclassification, and unmeasured confounders would enhance RWE credibility in light of RWD source-related limitations, and is being strongly considered by task forces in Japan. Overall, the development of guidance for best practices on data source selection, design transparency, and analytical methods to address different sources of biases and robustness in the process of RWE generation will enhance credibility for stakeholders and local decision-makers.

Impact of sodium-glucose cotransporter-2 inhibitors on the risk of hip fracture in older patients in Japan using a nationwide administrative claims database: A matched case-control study

AIM

Some clinical trials have shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors are associated with fracture risk. However, this notion remains controversial. This study aimed to evaluate hip fracture risk after the use of SGLT2 inhibitors while controlling for factors that may affect fracture risk. Furthermore, hip fracture risk is evaluated in relation to the SGLT2 inhibitors component and its concomitant use with other antidiabetic agents.

METHODS

Using large-scale real-world data, this case-control study investigated hospitalized patients between January 2018 and December 2020. Patients were aged 65-89 years and had been prescribed with SGLT2 inhibitors at least twice. Patients with hip fracture (cases) and those without (controls) were identified via 1:3 matching according to sex, age (±3 years), hospital size classification, and number of concomitant antidiabetic agents. Exposure to SGLT2 inhibitors of the cases and controls was compared with the use of multivariate conditional logistic regression.

RESULTS

After matching, 396 cases and 1081 controls were identified. The adjusted odds ratio for patients receiving treatment with SGLT2 inhibitors was 0.83 (95% confidence interval: 0.55-1.26), indicating no increase in hip fracture risk. Additionally, no increased risk was observed with respect to SGLT2 inhibitors by component or concomitant use with other antidiabetic agents.

CONCLUSION

Our study showed that SGLT2 inhibitors do not increase hip fractures in older patients. However, because the risk assessment of SGLT2 inhibitors by component and their concomitant use with other antidiabetic agents is based on a limited number of patients, it is important to interpret the results with caution. Geriatr Gerontol Int 2023; ••: ••-••.

Association between the Use of Suvorexant and Hip Fracture in Older Adults in Japan Using a Nationwide Administrative Claims Database: A Matched Case-Control Study

BACKGROUND AND OBJECTIVE

The use of benzodiazepines and nonbenzodiazepines increases the risk for hip fracture, but the effect of suvorexant, an orexin receptor antagonist, is not clear. The objective of this study was to investigate the association between suvorexant use and hip fractures in older adults.

METHODS

A case-control study was conducted using real-world data (RWD) from Medical Data Vision Co., Ltd. with patients hospitalized between January 2019 and December 2020. Patients were aged 65-84 years and had been prescribed suvorexant at least once. Patients with hip fracture (cases) and those without (controls) were identified by matching up to 1:4 for sex, age (± 2 years), and hospital size category. Suvorexant exposure was identified the day before hospitalization. Hip fracture risk associated with suvorexant was presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI) using conditional logistic regression analysis.

RESULTS

Matching identified 389 cases and 1509 controls. The risk of hip fracture was not increased in patients treated with suvorexant [aOR: 0.86, 95% confidence interval (CI) 0.61-1.20]. Additionally, concomitant use of suvorexant with other hypnotics did not increase the risk. Benzodiazepines (1.01, 0.46-2.22), nonbenzodiazepines (1.16, 0.57-2.34), and melatonin (1.80, 0.82-3.94) were combined with suvorexant. The risk was increased for the use of benzodiazepine without suvorexant (1.88, 1.10-3.21).

CONCLUSIONS

Using RWD in Japanese older adults, we showed that sleep therapy with suvorexant was not associated with an increased risk of hip fracture. The results provide evidence-based drug safety information for the selection of hypnotics for sleep disorders, which increase with age.

EXAcerbations of COPD and their OutcomeS on CardioVascular diseases (EXACOS-CV) Programme: protocol of multicountry observational cohort studies

INTRODUCTION

In patients with chronic obstructive pulmonary disease (COPD), the risk of certain cardiovascular (CV) events is increased by threefold to fivefold in the year following acute exacerbation of COPD (AECOPD), compared with a non-exacerbation period. While the effect of severe AECOPD is well established, the relationship of moderate exacerbation or prior exacerbation to elevated risk of CV events is less clear. We will conduct cohort studies in multiple countries to further characterise the association between AECOPD and CV events.

METHODS AND ANALYSIS

Retrospective longitudinal cohort studies will be conducted within routinely collected electronic healthcare records or claims databases. The study cohorts will include patients meeting inclusion criteria for COPD between 1 January 2014 and 31 December 2018. Moderate exacerbation is defined as an outpatient visit and/or medication dispensation/prescription for exacerbation; severe exacerbation is defined as hospitalisation for COPD. The primary outcomes of interest are the time to (1) first hospitalisation for a CV event (including acute coronary syndrome, heart failure, arrhythmias or cerebral ischaemia) since cohort entry or (2) death. Time-dependent Cox proportional hazards models will compare the hazard of a CV event between exposed periods following exacerbation (split into these periods: 1-7, 8-14, 15-30, 31-180 and 181-365 days) and the unexposed reference time period, adjusted on time-fixed and time-varying confounders.

ETHICS AND DISSEMINATION

Studies have been approved in Canada, Japan, the Netherlands, Spain and the UK, where an institutional review board is mandated. For each study, the results will be published in peer-reviewed journals.

The Current Status of Secondary Use of Claims, Electronic Medical Records, and Electronic Health Records in Epidemiology in Japan: Narrative Literature Review

BACKGROUND

Real-world data, such as claims, electronic medical records (EMRs), and electronic health records (EHRs), are increasingly being used in clinical epidemiology. Understanding the current status of existing approaches can help in designing high-quality epidemiological studies.

OBJECTIVE

We conducted a comprehensive narrative literature review to clarify the secondary use of claims, EMRs, and EHRs in clinical epidemiology in Japan.

METHODS

We searched peer-reviewed publications in PubMed from January 1, 2006, to June 30, 2021 (the date of search), which met the following 3 inclusion criteria: involvement of claims, EMRs, EHRs, or medical receipt data; mention of Japan; and published from January 1, 2006, to June 30, 2021. Eligible articles that met any of the following 6 exclusion criteria were filtered: review articles; non-disease-related articles; articles in which the Japanese population is not the sample; articles without claims, EMRs, or EHRs; full text not available; and articles without statistical analysis. Investigations of the titles, abstracts, and full texts of eligible articles were conducted automatically or manually, from which 7 categories of key information were collected. The information included organization, study design, real-world data type, database, disease, outcome, and statistical method.

RESULTS

A total of 620 eligible articles were identified for this narrative literature review. The results of the 7 categories suggested that most of the studies were conducted by academic institutes (n=429); the cohort study was the primary design that longitudinally measured outcomes of proper patients (n=533); 594 studies used claims data; the use of databases was concentrated in well-known commercial and public databases; infections (n=105), cardiovascular diseases (n=100), neoplasms (n=78), and nutritional and metabolic diseases (n=75) were the most studied diseases; most studies have focused on measuring treatment patterns (n=218), physiological or clinical characteristics (n=184), and mortality (n=137); and multivariate models were commonly used (n=414). Most (375/414, 90.6%) of these multivariate modeling studies were performed for confounder adjustment. Logistic regression was the first choice for assessing many of the outcomes, with the exception of hospitalization or hospital stay and resource use or costs, for both of which linear regression was commonly used.

CONCLUSIONS

This literature review provides a good understanding of the current status and trends in the use of claims, EMRs, and EHRs data in clinical epidemiology in Japan. The results demonstrated appropriate statistical methods regarding different outcomes, Japan-specific trends of disease areas, and the lack of use of artificial intelligence techniques in existing studies. In the future, a more precise comparison of relevant domestic research with worldwide research will be conducted to clarify the Japan-specific status and challenges.

An Attempt to Replicate Randomized Trials of Diabetes Treatments Using a Japanese Administrative Claims and Health Checkup Database: A Feasibility Study

BACKGROUND

Use of real-world evidence (RWE) has been limited for evaluating effectiveness because of the lack of confidence in its reliability. Examining whether a rigorously designed observational study using real-world data (RWD) can reproduce the results of a randomized controlled trial (RCT) will provide insights into the implementation of high-quality RWE studies that can produce valid conclusions.

OBJECTIVE

We aimed to replicate published RCTs using a Japanese claims and health checkup database and examine whether the emulated RWE studies' results agree with those of the original RCTs.

METHODS

We selected three RCTs on diabetes medications for replication in patients with type 2 diabetes. The study outcome was either the change or percentage change in HbA1c levels from baseline. We designed three observational studies using the RWD to mimic the critical study elements of the respective RCTs as closely as possible. We performed 1:1 propensity score nearest-neighbor matching to balance the groups for potential confounders. The differences in outcomes between the groups and their 95% confidence intervals (CIs) were calculated in each RWE study, and the results were compared with those of the RCT.

RESULTS

Patient characteristics, such as age, sex, and duration of diabetes, differed between the RWE studies and RCTs. In Trial 1 emulation, the percentage changes in HbA1c levels were larger in the treatment group than in the comparator group (difference -6.21, 95% confidence interval (CI) -11.01 to -1.40). In Trial 2, the change in HbA1c level was larger in the treatment group (difference -0.01; 95% CI -0.25 to 0.23), and in Trial 3, it was smaller in the treatment group (difference 0.46; 95% CI -0.01 to 0.94). These results did not show regulatory or estimate agreement with the RCTs.

CONCLUSIONS

None of the three emulated RWE studies using this claims and health checkup database reproduced the same conclusions as the RCTs. These discrepancies could largely be attributed to design differences between RWE studies and RCTs, primarily due to the lack of necessary data in the database. This particular RWD source may not be the best fit for evaluating treatment effects using laboratory data as the study outcome.

Impact of the COVID-19 pandemic on the incidence of healthcare facility-onset Clostridioides difficile infection in hospitalized patients with sepsis: Interrupted time series analysis using Japanese Diagnosis Procedure Combination data

OBJECTIVES

Healthcare facility-onset Clostridioides difficile infection (HO-CDI) is a major nosocomial infection associated with high mortality and healthcare costs. We aimed to determine if HO-CDI incidence decreased due to the COVID-19 pandemic. We hypothesized that the pandemic decreased HO-CDI as healthcare workers became more diligent in handwashing and sanitization.

METHODS

In this retrospective cohort study, adult patients with sepsis hospitalized in general wards from January 2018 to February 2021 were identified using a nationwide Japanese administrative database. Patients were divided into two groups according to the hospitalization date (before and after the first declaration of a state of emergency). The primary outcome was a change in the level of the HO-CDI monthly incidence ratio (per 10000 patient-days).

RESULTS

Of the 49,156 eligible hospitalizations for sepsis, 41,870 were before and 7,283 were after the first state of emergency declaration. Interrupted time-series (ITS) analysis showed no significant difference in the HO-CDI incidence ratio after Japan's first state of emergency declaration (level change -1.0, 95% confidence interval (CI) -8.6 to 6.6, p = 0.8, slope change 0.06, 95% CI -0.17 to 0.3, p = 0.6). The overall HO-CDI incidence ratio was 3.86/10000 patient-days (interquartile range 2.97-4.53); higher incidence existed in subgroups with older adults or a lower Barthel index at admission.

CONCLUSIONS

No significant change in HO-CDI incidence was observed in patients with sepsis hospitalized in general wards before and after Japan's first state of emergency declaration. Our study revealed that HO-CDI in general wards in Japan had been consistently decreasing since before the COVID-19 pandemic.

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.

Cost-effectiveness analysis of cardiac implantable electronic devices with reactive atrial-based antitachycardia pacing

AIMS

Reactive atrial-based anti-tachycardia pacing (rATP) in pacemakers (PMs) and cardiac resynchronization therapy defibrillators (CRT-Ds) has been reported to prevent progression of atrial fibrillation, and this reduced progression is expected to decrease the risk of complications such as stroke and heart failure (HF). This study aimed to assess the cost-effectiveness of rATP in PMs and CRT-Ds in the Japanese public health insurance system.

METHODS AND RESULTS

We developed a Markov model comprising five states: bradycardia, post-stroke, mild HF, severe HF, and death. For devices with rATP and control devices without rATP, we compared the incremental cost-effectiveness ratio (ICER) from the payer's perspective. Costs were estimated from healthcare resource utilisation data in a Japanese claims database. We evaluated model uncertainty by analysing two scenarios for each device. The ICER was 763 729 JPY/QALY (5616 EUR/QALY) for PMs and 1,393 280 JPY/QALY (10 245 EUR/QALY) for CRT-Ds. In all scenarios, ICERs were below 5 million JPY/QALY (36 765 EUR/QALY), supporting robustness of the results.

CONCLUSION

According to a willingness to pay threshold of 5 million JPY/QALY, the devices with rATP were cost-effective compared with control devices without rATP, showing that the higher reimbursement price of the functional categories with rATP is justified from a healthcare economic perspective.

Clinical features of Japanese patients with acute hepatic porphyria

Acute hepatic porphyria (AHP) is a family of rare genetic diseases of heme biosynthesis characterized by severe neurovisceral attacks. The clinical characteristics of patients with AHP as well as the prevalence of AHP in Japan are not well understood. The objectives of this study were to describe clinical characteristics of AHP at time of diagnosis in Japanese patients and to estimate the prevalence of AHP. Patients with porphyria were selected from Japan's Medical Data Vision health care claims database between April 2008 and June 2020. Patient characteristics before and at time of AHP diagnosis were evaluated. Prevalence per 100 000 was estimated during the study period. A total of 391 cases of AHP were included. At time of AHP diagnosis, mean age was 44 years, and the most common type was acute intermittent porphyria. Median time to diagnosis was 3 months, but some patients remained undiagnosed for several years. The most common complications included metabolic disorders (54%) and diabetes mellitus (39%). In addition, the well-known complications of AHP, including hypertension (22%) and malignant neoplasms of digestive organs (22%), were observed. About 10% of patients received medications that may have aggravated porphyria attacks. The estimated prevalence of AHP in Japan during the study period was 1.18 cases per 100 000 population. At time of diagnosis, many patients with AHP in Japan are already experiencing a high burden of disease-related complications. Raising AHP awareness may aid physicians in providing an earlier diagnosis and reducing lifetime disease burden.

Impact of "time zero" of Follow-Up Settings in a Comparative Effectiveness Study Using Real-World Data with a Non-user Comparator: Comparison of Six Different Settings

BACKGROUND

Time-related bias can lead to misleading conclusions. Properly setting the "time zero" of follow-up is crucial for avoiding these biases. However, the time-zero setting is challenging when comparing users and non-users of a study drug because the latter do not have a time point for starting treatment.

OBJECTIVE

This methodological study aimed to illustrate the impact of different time-zero settings on effect estimates in a comparative effectiveness study using real-world data with a non-user comparator.

METHODS

Data for type 2 diabetes patients were extracted from an administrative claims database, and the onset of diabetic retinopathy (study outcome) was compared between users (treatment group) and non-users (non-use group) of lipid-lowering agents. We applied six time-zero settings to the same dataset. The adjusted hazard ratio (HR) for the outcome was estimated using a Cox regression model in each time-zero setting, and the obtained results were compared among the settings.

RESULTS

Of the six settings, three (study entry date [SED] vs SED [naïve approach], treatment initiation [TI] vs SED, TI vs Matched [random order]) showed that the treatment had a reduced risk of the outcome (HR [95% CI]: 0.65 [0.61-0.69], 0.92 [0.86-0.97], and 0.76 [0.71-0.82], respectively), one (TI vs Random) had an increased risk (HR [95% CI]: 1.52 [1.40-1.64]) , and two (SED vs SED [cloning method], and TI vs Matched [systematic order]) had neither increased nor decreased risk (HR [95% CI]: 0.95 [0.93-1.13], and 0.99 [0.93-1.07], respectively).

CONCLUSIONS

This study demonstrates that different time-zero settings can lead to different conclusions, even if the same dataset is analyzed for the same research question, probably because improper settings can introduce bias. To minimize such biases, researchers should carefully define time zero, particularly when designing a non-user comparator study using real-world data.

Trend in neuraxial morphine use and postoperative analgesia after cesarean delivery in Japan from 2005 to 2020

The increasing rate of cesarean deliveries warrants obstetric anesthesiologists to deliver high-quality post-cesarean delivery analgesia. The aim of this study was to evaluate the temporal trends in the use of neuraxial morphine for cesarean deliveries and to describe the current postoperative analgesia practices. A retrospective cohort study using nationwide health insurance claims databases was conducted from 2005 to 2020 in Japan. Pregnant women who had undergone cesarean deliveries were included. The annual rate of neuraxial morphine use was extracted and analyzed. Additionally, we explored the patient- and facility-level factors associated with neuraxial morphine use through a multilevel logistic regression analysis. The cohort included 65,208 cesarean delivery cases from 2275 institutions. The prevalence of neuraxial morphine use was 16.0% (95% confidence interval [CI], 15.8-16.3) in the overall cohort. Intrathecal morphine was used in 20.6% (95% CI, 20.2-21.0) of spinal anesthesia cases. The trend in neuraxial morphine use steadily increased from 2005 to 2020. The significant predictors of neuraxial morphine use included spinal anesthesia, recent surgery, large medical facilities, and academic hospitals. Variations in the utilization of postoperative analgesia were observed. Our study described the current trend of neuraxial morphine use and the variation in postoperative analgesia practice in Japan.