著者
Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.2, no.2, pp.33-37, 2020 (Released:2020-04-28)
参考文献数
27
被引用文献数
9 34

Propensity score is defined as the probability of each individual being assigned to the treatment group. Propensity score analysis has recently become the sine qua non of comparative effectiveness studies using retrospective observational data. The present report provides useful information on how to use propensity score analysis as a tool for estimating treatment effects with observational data, including (i) assumptions for propensity score analysis, (ii) how to estimate propensity scores and evaluate propensity score distribution, and (iii) four methods of using propensity scores to control covariates: matching, adjustment, stratification, and inverse probability of treatment weighting.
著者
So Sato Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.5, no.2, pp.58-64, 2023 (Released:2023-04-01)
参考文献数
31
被引用文献数
2

BACKGROUNDAdministrative 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.METHODSStudies 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.RESULTSOverall, 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.CONCLUSIONSSince 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.
著者
Daisuke Shigemi Hiroki Matsui Kiyohide Fushimi Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.1, no.1, pp.11-17, 2019 (Released:2020-06-12)
参考文献数
23
被引用文献数
2

BACKGROUNDAnti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disease with multiple neurologic symptoms with or without a tumor, including ovarian teratoma. In the present study, a national inpatient database in Japan was used to investigate the characteristics, treatment, and outcomes of hospitalized patients with anti-NMDAR encephalitis who received initial treatment.METHODSUsing the Diagnosis Procedure Combination database, we identified all patients who were diagnosed with anti-NMDAR encephalitis and received initial first-line treatments (methylprednisolone, intravenous immunoglobulin, plasma exchange, and tumor removal) and second-line treatments (cyclophosphamide and rituximab) from July 2010 to March 2017. We excluded patients who received no immunotherapy or surgical treatment and those for whom data were missing. We investigated the characteristics, treatment, and outcomes of eligible patients.RESULTSIn total, 163 eligible patients were identified. Of these patients, 116 (71%) were female and 44 (28%) were ≤19 years of age. Among the female patients, 44 (38%) had a tumor. Thirty-nine patients (24%) were admitted to the intensive care unit during their hospitalization. Methylprednisolone, intravenous immunoglobulin, and plasma exchange were used as initial therapy in 82%, 56%, and 34% of patients, respectively. Second-line treatments were rarely used. Most patients were alert or had a slight disturbance of consciousness upon discharge. The proportion of patients discharged to home was 55%.CONCLUSIONSThe results of this Japanese study on anti-NMDAR encephalitis suggest that patients’ characteristics and outcomes including the male-to-female ratio, proportion of associated tumors, treatment options, and consciousness disturbance may differ from those in previous reports from other countries.
著者
Naoki Hirose Miho Ishimaru Kojiro Morita Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.2, no.1, pp.13-26, 2020 (Released:2020-05-14)
参考文献数
95
被引用文献数
7 37

BACKGROUNDElectronic health databases are increasingly used for research purposes. The Japanese National Database of Health Insurance Claims and Specific Health Checkups (NDB) is a large national administrative claims database. We reviewed published original articles that used the NDB.METHODSStudies published from January 2011 to June 2019 using the NDB were identified through PubMed and the academic product lists of the NDB, following the PRISMA guidelines.RESULTS68 studies were included in our review (43 were in English and 25 were in Japanese). The first NDB study in English was published in 2015, which was 4 years after the NDB was released for research purposes. The average annual growth rate of the number of NDB studies in English was 237% after the first publication of an NDB study in English. Descriptive studies were the most common study design (n = 42), and the Clinical Medicine was the most common research area (n = 18). The study strength most frequently mentioned by authors of the NDB studies was the large sample size. In terms of limitations, authors most frequently mentioned the lack of important data and validation studies.CONCLUSIONSSince its release, the NDB has increasingly attracted attention, and the number of studies using the NDB has grown rapidly. The large sample size and wide array of health care data in the NDB enabled researchers to conduct health service research in various research areas with several study designs. Finally, our review suggests to policy makers that administrative database should be constructed and managed with the environment which promote researchers access to the database and link it to other databases. Although the protection of respondents’ privacy should be carefully considered, higher accessibility and data linkage may maximize the potential of the administrative database and may enable researchers to produce more valuable health service researches for policy making in health care.
著者
Asuka Tsuchiya
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.3, no.2, pp.37-45, 2021 (Released:2021-04-01)
参考文献数
19
被引用文献数
1

In clinical epidemiological studies, many exposures and confounders are time dependent. In the presence of time-dependent confounders affected by previous exposures, the usual analytic methods may introduce biases. Marginal structural models are used to deal with time-dependent confounders and exposures. A marginal structural model is a regression model for a pseudo-population using the concept of a potential outcome. The inverse probability of treatment and censoring weighting method is used to create a pseudo-population in which the effects of baseline confounders and time-dependent confounders can be removed when estimating the causal effect of the exposure on the outcome event. If the accuracy of the weights is high, the inverse probability of treatment and censoring weighting method is reliable and the bias of the marginal structural model is small. After the weights are created, a weighted regression model is applied to calculate the treatment effect. This seminar series paper introduces time-dependent confounders, time-dependent treatments, and marginal structural models.
著者
Hidehiro Someko Yuki Kataoka Taku Obara
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
pp.23013, (Released:2023-05-18)

Drug fever is an adverse drug reaction accompanied by a febrile response and is a common problem among clinicians, hence an updated knowledge of drug fever is important. A consensus regarding the definition of drug fever is lacking. Thus, descriptions of drug fever in previous literature are often inconsistent. In this narrative review, we summarized various features of drug fever, including its definition, epidemiology, risk factors, clinical presentation, diagnosis, treatment and prognosis, based on the earliest literature. Recent advances in information technology have encouraged researchers to use pharmacovigilance databases for clinical and pharmacological research. We outlined how a pharmacovigilance database, along with recently developed research methods, could be used to research drug fever.
著者
Masao Iwagami Tomohiro Shinozaki
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.4, no.2, pp.33-40, 2022 (Released:2022-04-04)
参考文献数
27
被引用文献数
14

Matching is a technique through which patients with and without an outcome of interest (in case-control studies) or patients with and without an exposure of interest (in cohort studies) are sampled from an underlying cohort to have the same or similar distributions of some characteristics. This technique is used to increase the statistical efficiency and cost efficiency of studies. In case-control studies, besides time in risk set sampling, controls are often matched for each case with respect to important confounding factors, such as age and sex, and covariates with a large number of values or levels, such as area of residence (e.g., post code) and clinics/hospitals. In the statistical analysis of matched case-control studies, fixed-effect models such as the Mantel-Haenszel odds ratio estimator and conditional logistic regression model are needed to stratify matched case-control sets and remove selection bias artificially introduced by sampling controls. In cohort studies, exact matching is used to increase study efficiency and remove or reduce confounding effects of matching factors. Propensity score matching is another matching method whereby patients with and without exposure are matched based on estimated propensity scores to receive exposure. If appropriately used, matching can improve study efficiency without introducing bias and could also present results that are more intuitive for clinicians.
著者
Takeshi Unoki Hideaki Sakuramoto Shunsuke Taito Yuki Kataoka
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.3, no.3, pp.78-87, 2021 (Released:2021-07-01)
参考文献数
24

BACKGROUNDAlthough the majority of medical professionals recognize unplanned extubation as a critical accident, its relationship with the clinical outcomes of ventilated patients is controversial. The purpose of this study was to understand whether unplanned extubation, including self-extubation and accidental extubation, is a prognostic factor for clinical outcomes of mechanically ventilated adult patients.METHODSA pre-specified protocol was registered on PROSPERO (CRD42019120976). EMBASE, MEDLINE, CINAHL, and the ICTRP were searched on December 25, 2018 and February 5, 2020. The primary outcome was hospital mortality, and the secondary outcomes were ICU mortality, ICU and hospital length of stay, duration of mechanical ventilation, proportion of reintubation, and cost.RESULTSOf the 3216 articles retrieved, 11 were selected for the systematic review, and 9 met the criteria for the meta-analysis. Self-extubation was significantly associated with lower hospital mortality (OR = 0.49, 95% CI 0.30–0.81; certainty of evidence: moderate) and unplanned extubation was associated with ICU mortality (OR = 0.34, 95% CI 0.17–0.69; certainty of evidence: moderate). There were no significant between-group differences in lengths of hospital or ICU stay, with mean differences of 1.71 days (95% CI −7.68 to 11.69; certainty of evidence: very low) and 1.26 days (95% CI −3.58 to 6.10; certainty of evidence: very low), respectively.CONCLUSIONSSelf-extubation is associated with lower patient mortality, but a definitive conclusion cannot be made due to methodological limitations.
著者
Takaaki Konishi Haruhi Inokuchi Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
pp.24001, (Released:2023-06-10)
被引用文献数
1

In Japan, a public long-term care insurance system was launched in 2000. Residents can receive long-term care according to their care needs, as determined by a nationally standardized certification system. The present report describes the details of the long-term care services covered by public insurance. The Long-Term Care Insurance Act categorizes services into three major types: in-home, nursing-home, and community-based long-term care services. In-home care services include visiting, commuting, short-stay, and other services. Welfare, health, and medical facilities provide nursing-home care services for the elderly. Community-based care services were categorized into visiting, commuting, nursing-home, and composite services.
著者
Masao Iwagami Hiroki Matsui
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.4, no.3, pp.72-80, 2022 (Released:2022-07-01)
参考文献数
38
被引用文献数
4

Clinical prediction models include a diagnostic prediction model to estimate the probability of an individual currently having a disease (e.g., pulmonary embolism) and a prognostic prediction model to estimate the probability of an individual developing a specific health outcome over a specific time period (e.g., myocardial infarction and stroke in 10 years). Clinical prediction models can be developed by applying traditional regression models (e.g., logistic and Cox regression models) or emerging machine learning models to real-world data, such as electronic health records and administrative claims data. For derivation, researchers select candidate variables based on a literature review and clinical knowledge, and predictor variables in the final model based on pre-defined criteria (e.g., thresholds for the size of relative risk and p-values) or strategies such as the stepwise regression and the least absolute shrinkage and selection operator (LASSO) regression. For validation, the clinical prediction model’s performance is evaluated in terms of goodness of fit (e.g., R2), discrimination (e.g., area under the receiver operating characteristic curve or c-statistics), and calibration (e.g., calibration plot and Hosmer-Lemeshow test). Performance of a new variable added to an existing clinical prediction model is evaluated in terms of reclassification (e.g., net reclassification improvement and integrated discrimination improvement). The model should be validated using the original data to examine internal validity through methods such as resampling (e.g., cross-validation and bootstrapping) and using other participants’ data to examine external validity. For successful implementation of a clinical prediction model in actual clinical practice, presentation methods such as paper-based (nomogram) or web-based calculator and an easy-to-use risk score should be considered.
著者
Jun Komiyama Masao Iwagami Takahiro Mori Naoaki Kuroda Xueying Jin Tomoko Ito Nanako Tamiya
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.4, no.1, pp.11-19, 2022 (Released:2022-01-07)
参考文献数
36
被引用文献数
1

BACKGROUNDAlthough outpatient cardiac rehabilitation has been shown to be effective, the participation status of older cardiac patients is unclear in real-world settings. We investigated the proportion and associated factors of outpatient cardiac rehabilitation participation among older patients with heart diseases after cardiac intervention.METHODSWe analyzed data from medical and long-term care insurance claims data from two municipalities in Japan. The data coverage period was between April 2014 and March 2019 in City A and between April 2012 and November 2016 in City B. We identified patients aged ≥65 years with post-operative acute myocardial infarction, angina pectoris, or heart valve disease. We estimated the proportion of cardiac rehabilitation participation and conducted logistic regression to identify factors (age, sex, type of cardiac disease, open-heart surgery, Charlson comorbidity index, long-term care need level, catecholamine use, inpatient cardiac rehabilitation, and hospital volume for cardiac rehabilitation) associated with outpatient cardiac rehabilitation participation.RESULTSA total of 690 patients were included in this study. The proportion of patients receiving outpatient cardiac rehabilitation was 9.0% overall. Multivariable logistic regression analysis suggested that men (adjusted OR 3.98; 95% CI 1.69–9.37), acute myocardial infarction (adjusted OR 2.76; 95% CI 1.20–6.36; reference angina pectoris), inpatient cardiac rehabilitation (adjusted OR 17.01; 95% CI 5.33–54.24), and “hospital volume” for cardiac rehabilitation (adjusted OR 4.35; 95% CI 1.14–16.57 for high-volume hospitals; reference low-volume hospital) were independently associated with outpatient cardiac rehabilitation.CONCLUSIONSThe participation rate of outpatient cardiac rehabilitation among older post-operative cardiac patients was suboptimal. Further studies are warranted to examine its generalizability and whether a targeted approach to a group of patients who are less likely to receive outpatient cardiac rehabilitation could improve the participation rate.
著者
Shotaro Aso Hideo Yasunaga
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.2, no.3, pp.69-74, 2020 (Released:2020-07-01)
参考文献数
19
被引用文献数
7 12

In theory, instrumental variable (IV) analysis, like randomized controlled trials, can adjust for measured and unmeasured confounders. IVs need to meet the following three conditions: (i) they are associated with treatment assignment; (ii) they have no direct association with the outcome and are associated with the outcome exclusively through the treatment; and (iii) they are not associated with any of the measured confounders. Studies have presented several types of IV, including preferences of the facility or physician, differential distance, and days of the week. Two types of estimation method have been introduced: two-stage least squares and two-stage residual inclusion. The assumption of monotonicity limits the generalizability of estimates of causal effects in IV analysis because the target population of IV analysis is “compliers” (those who always comply with the assigned treatment). IV analysis using two or more IVs is feasible but requires the overidentifying restriction test. Despite several limitations, IV analysis is a feasible option that may be used for causal inference in comparative effectiveness studies using retrospective observational data.
著者
Keisuke Anan Yuki Kataoka Kazuya Ichikado Kodai Kawamura Takeshi Johkoh Kiminori Fujimoto Kazunori Tobino Ryo Tachikawa Hiroyuki Ito Takahito Nakamura Tomoo Kishaba Minoru Inomata Yosuke Yamamoto
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
pp.22008, (Released:2022-02-09)
被引用文献数
4

Background: This study aimed to develop criteria for identifying patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) from Japanese administrative data and validate the pre-existing criteria.Methods: This retrospective, multi-center validation study was conducted at eight institutes in Japan to verify the diagnostic accuracy of the disease name for AE-IPF. We used the Japanese Diagnosis Procedure Combination data to identify patients with a disease name that could meet the diagnostic criteria for AE-IPF, who were admitted to the eight institutes from January 2016 to February 2019. As a reference standard, two respiratory physicians performed a chart review to determine whether the patients had a disease that met the diagnostic criteria for AE-IPF. Furthermore, two radiologists interpreted the chest computed tomography findings of cases considered AE-IPF and confirmed the diagnosis. We calculated the positive predictive value (PPV) for each disease name and its combination. Results: We included 830 patients; among them, 216 were diagnosed with AE-IPF through the chart review. We combined the groups of disease names and yielded two criteria: the criteria with a high PPV (0.72 [95% confidence interval 0.62 to 0.81]) and that with a slightly less PPV (0.61 [0.53 to 0.68]) but more true positives. Pre-existing criteria showed a PPV of 0.40 (0.31 to 0.49).Conclusion: The criteria derived in this study for identifying AE-IPF from Japanese administrative data show a fair PPV. Although these criteria should be carefully interpreted according to the target population, our findings could be utilized in future database studies on AE-IPF.
著者
Gojiro Nakagami Kojiro Morita Hiroki Matsui Hideo Yasunaga Kiyohide Fushimi Hiromi Sanada
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.2, no.2, pp.38-50, 2020 (Released:2020-04-28)
参考文献数
31
被引用文献数
2 6

BACKGROUNDSThe presence of pressure injuries may affect patient discharge destination; however, no related large-scale survey has been conducted in Japan. This study aimed to evaluate the association between pressure injury status and discharge to home from Japanese acute-care hospitals.METHODSThis retrospective observational cohort study used the Japanese Diagnosis Procedure Combination database from July 1 to 31, 2014. We assessed 340,124 inpatients aged 65 years or older admitted from home. To examine the association between pressure injury status (none, healed, healing, stable, worsened, or developed) and home discharge, we employed multivariable logistic regressions; these were adjusted for patient characteristics and within-hospital clustering using generalized estimating equations.RESULTSThe prevalence of pressure injuries on admission was 1.9%; the overall proportion of hospital-acquired pressure injuries was 1.1%. The logistic regression analyses showed patients with superficial or deep pressure injuries were less likely to be discharged to home. Furthermore, poor pressure injury status (developed < worsened < stable < healing < healed) was associated with lower likelihood of discharge to home.CONCLUSIONSPoor pressure injury status negatively affected hospital discharge destination among elderly patients admitted from home.
著者
Kojiro Morita
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.3, no.4, pp.97-100, 2021 (Released:2021-10-01)
参考文献数
11
被引用文献数
1

Survival analysis is often used in studies of clinical epidemiology, but the existence of competing risks has not been adequately considered. Competing risks may hinder observation of the outcome of interest or modify the occurrence of the outcome. In the presence of competing risks, conventional survival analysis leads to biased results. To conduct a survival analysis in the presence of competing risks, researchers should select an appropriate method from the following two options: cause-specific hazard model and subdistribution hazard model. This article explains the issues raised by the presence of competing risks and describes methods to account for competing risks in survival analysis.
著者
Michimasa Fujiogi Nobuaki Michihata Hiroki Matsui Kiyohide Fushimi Hideo Yasunaga Jun Fujishiro
出版者
Society for Clinical Epidemiology
雑誌
Annals of Clinical Epidemiology (ISSN:24344338)
巻号頁・発行日
vol.2, no.2, pp.61-68, 2020 (Released:2020-04-28)
参考文献数
23

BACKGROUNDOmphalocele is frequently detected prenatally worldwide. Nevertheless, little is known about patient demographics, practice pattern and outcomes.METHODSWe examined patient demographics, treatment options, and outcomes for patients with omphalocele with and without severe chromosomal abnormalities (trisomy 13 and 18), July 2010–March 2016, using a nationwide database in Japan.RESULTSOf 399 patients with omphalocele, 89 had trisomy 13 or 18. The average birthweight was 2,449 g, and the average gestational age was 35 weeks; 65% had other congenital associated anomalies, including circulatory and chromosomal anomalies. About 85% of the patients received abdominoplasty. The median length of mechanical ventilation was 5 (0–30) days. The median length of stay (interquartile range) was 45 (21–94) days. Overall, 52% of the patients were discharged to home without home medical care; this percentage was 65% among those without trisomy 13 or 18. In-hospital mortality was 20% for the total sample of patients, while it was 49% for those with trisomy 13 or 18.CONCLUSIONSThe present study revealed the patient demographics, treatment practices, and discharge status of infants with omphalocele in Japan. This information is useful in aiding decision making on therapeutic strategies by medical staffs and the families of patients with omphalocele.