著者

Masao Iwagami Yoshinori Takeuchi

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.67-73, 2021 (Released:2021-07-01)

参考文献数

21

被引用文献数

6

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Self-controlled study designs, also known as case-only designs or Self-controlled Crossover Observational PharmacoEpidemiologic (SCOPE) studies, include case-crossover (CCO) and self-controlled case series (SCCS). These designs compare different time windows (i.e., lengths of time) within the same person. An SCCS compares the occurrence of an outcome (event) during periods with and without exposure in the same person, whereas a CCO compares periods with and without the outcome for exposure. The main strength of self-controlled study designs is that they can ignore confounding factors that do not change over time (e.g., sex, genetics, habitual healthy or unhealthy behaviors). The effect of these factors are canceled out through statistical analyses, even if they are unknown or unmeasured. However, self-controlled study designs cannot be used for all research questions. Assumptions specific to each study design are needed. In CCO, there should be no substantial changes in exposure trends during the study period, the exposure should be transient (intermittent), and the outcome should be abrupt (sudden). In SCCS, event rates should be constant within each defined period and events must be independently recurrent or rare. In addition, the occurrence of an event should not affect subsequent exposures. Self-controlled study designs may be particularly useful in studies using electronic health records, in which some (time-invariant) confounding factors may not have been recorded, provided that the research question meets the assumptions required for each study design.

著者

Hiroki Maki Hidetaka Wakabayashi Keisuke Maeda Mariko Nakamichi Kazumi Kubota Ryo Momosaki

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

vol.5, no.3, pp.88-94, 2023 (Released:2023-07-04)

参考文献数

22

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BACKGROUNDThe Comorbidity Polypharmacy Score (CPS) is calculated by the number of drugs carried plus the number of comorbidities on admission and divided into three categories (minor, 0–7; moderate, 8–14; and severe, 15+). This study investigates whether CPS can predict the clinical outcomes in older patients with hip fractures undergoing surgery.METHODSThis retrospective longitudinal study used a multicenter hospital-based database containing the Diagnosis Procedure Combination. Consecutive patients with hip fractures (ICD-10 codes S720 and S721) who were aged ≥65 years between April 2014 and August 2020 were included. We evaluated the predictive association between the CPS and Barthel Index (BI) efficiency. The primary outcome was defined as the BI efficiency, and the secondary outcome was the length of hospital stay.RESULTSWe enrolled 11,564 patients, and 80.5% of them were female. The mean age was 83.9 ± 6.5 years. The BI efficiency was the lowest in the CPS severe group with a median [interquartile range] of 0.67 [0.10, 1.43]. The length of hospital stay was the highest in the CPS severe group, with a median of 35 [21, 58]. Additionally, multiple linear regression analysis revealed that the CPS was independently associated with the BI efficiency (β = −0.100, 95% CI: −0.040, −0.029; P < 0.001) and the length of hospital stay (β = 0.047, 95% CI: 0.199, 0.366; P < 0.001).CONCLUSIONSAn increased CPS score is associated with low BI efficiency and longer length of hospital stay in patients with hip fractures.

著者

Takaaki Konishi 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.1, pp.1-4, 2023 (Released:2023-01-11)

参考文献数

14

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Health technology assessment (HTA) is implemented in the decision-making process for the reimbursement and pricing of drugs and medical devices around the world. This study presented the trend and characteristics of HTA research in Japan and worldwide. HTA research increased since the 2010s. Cancer was a prominent subject and the Markov model was a major analytical model in HTA research both globally and in Japan. In Japan, osteoporosis was a more popular topic, but there were fewer surgical research and review articles compared to the global trend. Since Japanese articles on HTA were much fewer than those from the United States, the United Kingdom, and China, various types of HTA research should be encouraged in Japan to promote product innovation and optimize medical expenditures.

著者

Michimasa Fujiogi Takaaki Konishi Nobuaki Michihata Yohei Hashimoto Hiroki Matsui Tetsuya Ishimaru 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

pp.23004, (Released:2022-09-29)

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Background: Little is known about perioperative outcomes after pediatric thyroidectomy. This study was performed to compare perioperative outcomes between children and adults undergoing thyroid cancer surgery using a nationwide inpatient database in Japan.Methods: Using the Japanese Diagnosis Procedure Combination database, we identified patients aged 0 to 40 years with thyroid cancer who underwent thyroidectomy from July 2010 to March 2020. To compare the occurrence of in-hospital morbidities including local complications (e.g., recurrent laryngeal nerve paralysis, postoperative bleeding), duration of anesthesia, postoperative length of stay, and total hospitalization costs between children (0–18 years) and adults (19–40 years), we used multivariable logistic regression analysis for the occurrence of in-hospital morbidities and linear regression for other outcomes. Results: For 16,016 eligible patients (666 children vs. 15,350 adults), no significant differences between the two groups were found in any in-hospital morbidity (5.4% vs. 5.9%; adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.57–1.14; P=0.23), local complications (5.0% vs. 5.5%; OR, 0.80; 95% CI, 0.55–1.15; P=0.22), recurrent laryngeal nerve paralysis (2.1% vs. 2.4%; OR, 0.78; 95% CI, 0.45–1.35; P=0.37), or postoperative bleeding (1.7% vs. 1.4%; OR, 0.99; 95% CI, 0.53–1.87; P=0.98). Children showed a longer duration of anesthesia (difference, 20 minutes; 95% CI, 13–27; P<0.001) and higher total costs (difference, 445 US dollars; 95% CI, 239–651; P<0.001) than adults.Conclusion: This large nationwide cohort study showed no significant difference in perioperative complications between children and adults undergoing thyroid cancer surgery.

著者

Aki Kuwauchi Satomi Yoshida Shiro Tanaka Sachiko Tanaka Chikashi Takeda Hiroshi Yonekura Isao Nahara Koji Kawakami

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

pp.22011, (Released:2022-03-11)

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BackgroundThe controversy concerning the benefits of pulmonary artery catheter (PAC)-based hemodynamic monitoring in cardiac surgeries has not been adequately addressed. This study aims to compare the all-cause mortality between the PAC with venous oxygen saturation monitoring and the Vigileo/FloTrac (FloTrac) system with central venous oxygen saturation monitoring in cardiac surgeries.MethodsThis nationwide retrospective study includes adult patients who underwent elective cardiac surgeries between April 2010 and October 2014, based on the Japanese health insurance claims database. The main outcome was 30-day all-cause mortality. Propensity scores (PS) were used to adjust for the confounding factors. Treatment effects were estimated using multivariable logistic regression analysis, including PS.ResultsA total of 5,838 patients were included in this study. The crude 30-day mortality rates were 2.4% (8/334) and 1.7% (96/5,504) in the FloTrac and PAC groups, respectively. After PS matching, the ORs for 30-day all-cause mortality, in-hospital mortality after PAC placement (vs. FloTrac) were 0.36 (95% CI: 0.05 – 2.37; p= 0.28) and 0.59 (95% CI: 0.16 – 2.20; p= 0.43), respectively. The amount of dobutamine was larger in the PAC group (281±31 mg vs 155±19 mg; p <0.001). There were no significant differences in the amounts of other inotropes, the volume of fluids, or blood transfusions.ConclusionsThe association between PAC (with venous oxygen saturation monitoring) and mortality in patients who underwent elective cardiac surgeries was unclear compared to FloTrac (with central venous oxygen saturation monitoring). Additional investigation is needed to evaluate the benefits of PAC-specific hemodynamic parameters in this population.

著者

Yuki Kataoka Tomohisa Baba Tatsuyoshi Ikenoue Yoshinori Matsuoka Junichi Matsumoto Junji Kumasawa Kentaro Tochitani Hiraku Funakoshi Tomohiro Hosoda Aiko Kugimiya Michinori Shirano Fumiko Hamabe Sachiyo Iwata Yoshiro Kitamura Tsubasa Goto Tomohiro Handa Shoji Kido Shingo Fukuma Noriyuki Tomiyama Toyohiro Hirai Takashi Ogura Japan COVID-19 AI team

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

pp.22014, (Released:2022-07-08)

被引用文献数

2

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Background: We aimed to develop and externally validate a novel machine learning model that can classify CT image findings as positive or negative for SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR).Methods: We used 2,928 images from a wide variety of case-control type data sources for the development and internal validation of the machine learning model. A total of 633 COVID-19 cases and 2,295 non-COVID-19 cases were included in the study. We randomly divided cases into training and tuning sets at a ratio of 8:2. For external validation, we used 893 images from 740 consecutive patients at 11 acute care hospitals suspected of having COVID-19 at the time of diagnosis. The dataset included 343 COVID-19 patients. The reference standard was RT-PCR.Results: In external validation, the sensitivity and specificity of the model were 0.869 and 0.432, at the low-level cutoff, 0.724 and 0.721, at the high-level cutoff. Area under the receiver operating characteristic was 0.76.Conclusions: Our machine learning model exhibited a high sensitivity in external validation datasets and may assist physicians to rule out COVID-19 diagnosis in a timely manner at emergency departments. Further studies are warranted to improve model specificity.

著者

Sachiko Ono Tadahiro Goto

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.63-71, 2022 (Released:2022-07-01)

参考文献数

46

被引用文献数

5

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Machine learning refers to a series of processes in which a computer finds rules from a vast amount of data. With recent advances in computer technology and the availability of a wide variety of health data, machine learning has rapidly developed and been applied in medical research. Currently, there are three types of machine learning: supervised, unsupervised, and reinforcement learning. In medical research, supervised learning is commonly used for diagnoses and prognoses, while unsupervised learning is used for phenotyping a disease, and reinforcement learning for maximizing favorable results, such as optimization of total patients’ waiting time in the emergency department. The present article focuses on the concept and application of supervised learning in medicine, the most commonly used machine learning approach in medicine, and provides a brief explanation of four algorithms widely used for prediction (random forests, gradient-boosted decision tree, support vector machine, and neural network). Among these algorithms, the neural network has further developed into deep learning algorithms to solve more complex tasks. Along with simple classification problems, deep learning is commonly used to process medical imaging, such as retinal fundus photographs for diabetic retinopathy diagnosis. Although machine learning can bring new insights into medicine by processing a vast amount of data that are often beyond human capacity, algorithms can also fail when domain knowledge is neglected. The combination of algorithms and human cognitive ability is a key to the successful application of machine learning in medicine.

著者

Takashi Fujiwara Masanobu Mizuta Eishu Nango Hisanobu Tamaki

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.88-95, 2021 (Released:2021-07-01)

参考文献数

22

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BACKGROUNDPrimary curative treatment of resectable laryngeal cancer includes surgery and chemoradiotherapy. Other treatment options include radiotherapy, chemoradiotherapy, partial laryngectomy, and total laryngectomy. Larynx-preserving treatments (partial laryngectomy, radiotherapy, and chemoradiotherapy) are recommended in early stage cases, although total laryngectomy is needed in advanced cases. Here, we evaluated trends in treatment strategies and identified the factors that are important in decision making.METHODSWe performed a retrospective analysis of data acquired from electronic medical records in Japan. Hospitalized laryngeal cancer patients admitted between January 2014 and December 2018 were included in our analyses. The primary outcome was the initial treatment.RESULTSA total of 363 patients (mean age 71.8 ± 9.5, male/female = 333/30) met the inclusion criteria. Of these, 10.1% of the patients were treated with total laryngectomy, while 17.9% underwent partial resection, 65.8% received radiotherapy (chemoradiotherapy), and 6.1% had no treatment. Larynx-preserving treatment was used in most T1–2 cases (96.9%), and 40% of the patients with T3 cancer underwent total laryngectomy (adjusted odds ratio 26.7 [95% CI, 9.29-91.6]). Of the T3 cancers that were treated, total laryngectomy was performed in only 26.7% of patients aged ≤65 years, but in more than 50% of those aged >65 years.CONCLUSIONSThis retrospective study showed that larynx-preserving treatments were used in most T1–2 cases, and suggested that T stage is the most important factor affecting decision making in the treatment of laryngeal cancer. Older patients with T3 disease tended to undergo total laryngectomy, and age is an important factor in the decision-making process for cases of T3 laryngeal cancer.

著者

Satoshi Kasuya Shotaro Aso Isao Takahashi

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

vol.5, no.3, pp.74-79, 2023 (Released:2023-07-04)

参考文献数

15

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BACKGROUNDExtracorporeal membrane oxygenation (ECMO) has been used for decades, but optimal anticoagulation control remains unknown. This study aimed to compare shorter target activated coagulation time (ACT) criteria with the usual target ACT criteria in terms of complications.METHODSWe retrospectively identified patients who received ECMO between 1 January 2013 and 31 December 2018 in an acute tertiary care hospital. Patients were divided into two groups: (I) those whose target ACT was 160–180 sec and (II) those whose target ACT was 180–220 sec. Cox proportional hazard models and Fine–Gray models adjusted for propensity score to account for the competing risk of death were used to compare the incidence of hemorrhage during ECMO between the groups.RESULTSWe identified 74 patients, 25 of whom were managed with target ACT 160–180 sec, and 49 of whom were managed with target ACT 180–220 sec. In crude analysis, the proportions of patients with hemorrhage in the under 180-sec group were significantly more than those in the over 180-sec group [60.0% (15/25) vs. 28.6% (14/49), p = 0.009]. Shorter target ACT was not associated with hemorrhage during ECMO in either Cox regression (hazard ratio, 1.67; 95% confidence interval, 0.59–4.80; p = 0.336) or Fine–Gray model (hazard ratio, 1.58; 95% confidence interval, 0.64–3.91; p = 0.324).CONCLUSIONSThe shorter ACT target was not associated with improved hemorrhage and inappropriate coagulation than the usual target ACT criteria. This study is the first to compare the ACT target of patients with ECMO.

著者

Yohei Hashimoto Hideo Yasunaga

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

vol.4, no.4, pp.101-109, 2022 (Released:2022-10-03)

参考文献数

35

被引用文献数

4

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Propensity score analysis has been widely used in observational studies to make a causal inference. This study introduces three assumptions for causal inferences—conditional exchangeability, positivity, and consistency—and five steps for propensity score (PS) analysis—1) construct appropriate PS models, 2) check overlap in PS, 3) apply appropriate weighting (inverse probability of treatment weighting, standardized mortality ratio weighting, matching weights, and overlap weights) or matching methods according to the target of inference, 4) check the balance of covariates, and 5) estimate the effect of exposure appropriately. Finally, the advantages of PS analyses over conventional multivariable regression are discussed.

著者

Yusuke Sasabuchi

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.1-5, 2022 (Released:2022-01-07)

参考文献数

9

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It is common clinical practice for physicians to refer to specific diagnostic criteria for day-to-day decision-making. In particular, whether or not to provide a particular treatment is often determined by the cutoff value of a relevant diagnostic marker. Regression discontinuity design (RDD) is a method for evaluating scenarios where intervention is determined by the certain cutoff value (e.g., threshold) of a continuous variable. RDD represents a powerful method for assessing intervention effects and outcomes. RDD is underutilized in clinical research and there are many opportunities to apply RDD in this setting. This article introduces the principles of RDD and provides examples of clinical studies that have used this design.

著者

Atsushi Nishikawa Eiko Yoshinaga Masaki Nakamura Masayoshi Suzuki Keiji Kido Naoto Tsujimoto Taeko Ishii Daisuke Koide

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.20-31, 2022 (Released:2022-01-07)

参考文献数

21

被引用文献数

10

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BACKGROUNDThis retrospective observational study validated case-finding algorithms for malignant tumors and serious infections in a Japanese administrative healthcare database.METHODSRandom samples of possible cases of each disease (January 2015–January 2018) from two hospitals participating in the Medical Data Vision Co., Ltd. (MDV) database were identified using combinations of ICD-10 diagnostic codes and other procedural/billing codes. For each disease, two physicians identified true cases among the random samples of possible cases by medical record review; a third physician made the final decision in cases where the two physicians disagreed. The accuracy of case-finding algorithms was assessed using positive predictive value (PPV) and sensitivity.RESULTSThere were 2,940 possible cases of malignant tumor; 180 were randomly selected and 108 were identified as true cases after medical record review. One case-finding algorithm gave a high PPV (64.1%) without substantial loss in sensitivity (90.7%) and included ICD-10 codes for malignancy and photographing/imaging. There were 3,559 possible cases of serious infection; 200 were randomly selected and 167 were identified as true cases after medical record review. Two case-finding algorithms gave a high PPV (85.6%) with no loss in sensitivity (100%). Both case-finding algorithms included the relevant diagnostic code and immunological infection test/other related test and, of these, one also included pathological diagnosis within 1 month of hospitalization.CONCLUSIONSThe case-finding algorithms in this study showed good PPV and sensitivity for identification of cases of malignant tumors and serious infections from an administrative healthcare database in Japan.

著者

Shungo Imai Kenji Momo Hitoshi Kashiwagi Yuki Sato Takayuki Miyai Mitsuru Sugawara Yoh Takekuma

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.6-10, 2022 (Released:2022-01-07)

参考文献数

15

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.1, no.3, pp.76-79, 2019 (Released:2020-05-19)

参考文献数

12

被引用文献数

39 218

著者

Shunsuke Taito Yuki Kataoka Takashi Ariie Shiho Oide Yasushi Tsujimoto

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.56-58, 2021 (Released:2021-04-01)

参考文献数

6

被引用文献数

4

著者

Yuki Kataoka Shiho Oide Takashi Ariie Yasushi Tsujimoto Toshi A. Furukawa

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.46-55, 2021 (Released:2021-04-01)

参考文献数

36

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BACKGROUNDThe objective of this study was to investigate the methodological quality of coronavirus disease 2019 (COVID-19) systematic reviews (SRs) indexed in medRxiv and PubMed, compared with Cochrane COVID Reviews.METHODSThis is a cross-sectional meta-epidemiological study. We searched medRxiv, PubMed, and Cochrane Database of Systematic Reviews for SRs of COVID-19. We evaluated the methodological quality using A MeaSurement Tool to Assess systematic Reviews (AMSTAR) checklists. The maximum AMSTAR score is 11, and minimum is 0. Higher score means better quality.RESULTSWe included 9 Cochrane reviews as well as randomly selected 100 non-Cochrane reviews in medRxiv and PubMed. Compared with Cochrane reviews (mean 9.33, standard deviation 1.32), the mean AMSTAR scores of the articles in medRxiv were lower (mean difference (MD): −2.85, 98.3% confidence intervals (CI): −0.96 to −4.74), and those in PubMed were also lower (MD: −3.28, 98.3%CI: −1.40 to −5.15), with no difference between the latter two.CONCLUSIONSReaders should pay attention to the potentially low methodological quality of SRs related to COVID-19 in both PubMed and medRxiv. Evidence users might be better to search the Cochrane Library rather than medRxiv or PubMed to search SRs related to COVID-19.

著者

Daisuke Shigemi Toshitaka Morishima Ayako Shibata Takahiro Tabuchi Hideo Yasunaga Isao Miyashiro

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.75-83, 2020 (Released:2020-07-01)

参考文献数

28

被引用文献数

1

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BACKGROUNDUnlike the recommendations made in many other countries, Japanese guidelines equally recommend radical hysterectomy or concurrent chemoradiotherapy for treatment of stage IIB cervical carcinoma. The main study objective was to compare the overall mortality of hysterectomy versus concurrent chemoradiotherapy as primary treatment in patients with localized or regionally extended cervical cancer.METHODSUsing Diagnosis Procedure Combination database combined with population-based cancer registry data in Osaka Prefecture, Japan, we conducted a retrospective cohort study. All adult patients who had been diagnosed with cervical cancer, registered in the population-based cancer registry from January 1, 2010 to December 31, 2015 were included. To compare overall mortality between patients who received radical hysterectomy and concurrent chemoradiotherapy as primary treatment, we performed a Cox regression analysis of the original cohort, and Kaplan-Meier analysis with stabilized inverse probability of treatment weights using propensity score.RESULTSAmong 740 eligible patients, 564 patients were included in the hysterectomy group and 176 patients were included in the concurrent chemoradiotherapy group. Primary hysterectomy was not independently associated with overall mortality (adjusted HR 0.70, 95% CI 0.46–1.07) by the Cox regression analysis. The Kaplan-Meier analysis with stabilized inverse probability of treatment weights did not show a significant difference in overall mortality between the two groups (P = 0.096).CONCLUSIONSThis study indicates that primary treatment type (hysterectomy versus concurrent chemoradiotherapy) was not statistically associated with overall mortality among patients diagnosed with localized or regionally extended cervical cancer.

著者

Tomotsugu Seki Masato Takeuchi Shin Kawasoe Kazufumi Takeuchi Ryusuke Miki Kenji Ueshima Koji Kawakami

出版者

Society for Clinical Epidemiology

雑誌

Annals of Clinical Epidemiology (ISSN:24344338)

巻号頁・発行日

vol.3, no.1, pp.10-26, 2021 (Released:2021-01-07)

参考文献数

32

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BACKGROUNDSurvival benefit of outpatient cardiac rehabilitation (CR) after acute myocardial infarction (AMI) has recently been contested under the current real-world clinical practice. We investigated whether outpatient CR was associated with lower mortality and morbidity risks among Japanese AMI patients.METHODSWe analyzed patients who were admitted for AMI and received both percutaneous coronary intervention and inpatient CR from January 2011 to December 2014, using a nationwide administrative database in Japan (final date of follow-up: July 31, 2016). We compared patients who received outpatient CR and who did not, and the primary outcome was a composite of all-cause death and recurrence of AMI after the landmark time-point of day 180 after discharge. We applied Cox proportional hazards model to estimate outcomes, and propensity-score matching was applied to adjust for baseline imbalances.RESULTSA total of 5,654 patients (mean [SD] age, 66.8 [12.4] years; 21.2% female; median follow-up period [IQR] 1.44 [0.87, 2.27] years), 730 (12.9%) participated in outpatient CR at least once within 180 days of discharge. Of 1,458 propensity-score matched patients, outpatient CR participation was associated with lower but statistically non-significant risks among the primary outcome (1.38 vs. 2.12 per 100 patient-years; HR = 0.71; 95%CI, 0.32 to 1.61).CONCLUSIONSAmong Japanese patients who admitted for AMI and received both percutaneous coronary intervention and inpatient CR, outpatient CR was underutilized, and associated with a statistically non-significant mortality and morbidity benefits. Further study is necessary to reaffirm the real-world effectiveness of outpatient CR under the current real-world clinical practice.