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Dive into the research topics where Takuya Kawahara is active.

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Featured researches published by Takuya Kawahara.


Journal of Epidemiology | 2016

Accuracy of Death Certificates and Assessment of Factors for Misclassification of Underlying Cause of Death

Makiko Naka Mieno; Noriko Tanaka; Tomio Arai; Takuya Kawahara; Aya Kuchiba; Shizukiyo Ishikawa; Motoji Sawabe

BACKGROUND Cause of death (COD) information taken from death certificates is often inaccurate and incomplete. However, the accuracy of Underlying CODs (UCODs) recorded on death certificates has not been comprehensively described when multiple diseases are present. METHODS A total of 450 consecutive autopsies performed at a geriatric hospital in Japan between February 2000 and August 2002 were studied. We evaluated the concordance rate, sensitivity, and specificity of major UCODs (cancer, heart disease, and pneumonia) reported on death certificates compared with a reference standard of pathologist assessment based on autopsy data and clinical records. Logistic regression analysis was performed to assess the effect of sex, age, comorbidity, and UCODs on misclassification. RESULTS The concordance rate was relatively high for cancer (81%) but low for heart disease (55%) and pneumonia (9%). The overall concordance rate was 48%. Sex and comorbidity did not affect UCOD misclassification rates, which tended to increase with patient age, although the association with age was also not significant. The strongest factor for misclassification was UCODs (P < 0.0001). Sensitivity and specificity for cancer were very high (80% and 96%, respectively), but sensitivity for heart disease and pneumonia was 60% and 46%, respectively. Specificity for each UCOD was more than 85%. CONCLUSIONS Researchers should be aware of the accuracy of COD data from death certificates used as research resources, especially for cases of elderly patients with pneumonia.


Vascular Medicine | 2018

Increase in skin perfusion pressure predicts amputation-free survival after lower extremity bypass surgery for critical limb ischemia:

Kota Yamamoto; Takuya Kawahara; Atsushi Akai; Toshihiko Isaji; Daisuke Akagi; Takuya Miyahara; Katsuyuki Hoshina

The objective of this study was to determine how postoperative skin perfusion pressure (SPP) as a measure of blood flow after revascularization affects limb prognosis in patients with critical limb ischemia (CLI). We retrospectively reviewed 223 consecutive bypass surgery cases performed in 192 patients with CLI during a 10-year period. SPP was measured 1–2 weeks before and after the procedure. An SPP of 40 mmHg was set as the cut-off value for revascularization. Patients were grouped according to their postoperative SPPs, and amputation-free survival (AFS) was analyzed. An SPP of ≥ 40 mmHg was recovered in 75% of the patients, but no significant difference was found between this group and the group that did not reach 40 mmHg. On the other hand, the values increased by ≥ 20 mmHg from the preoperative values in 70% of the patients. This group had a significantly better AFS than the group that did not increase by 20 mmHg. Logistic regression analysis revealed that (1) a preoperative SPP of < 20 mmHg and (2) a high serum albumin level (> 3.0 g/dL) were significant factors in increasing SPP by 20 mmHg. These results showed that an increase in SPP of ≥ 20 mmHg after bypass surgery was associated with better limb prognosis.


Oncology | 2017

Patient-Reported Outcome Results from the Open-Label Randomized Phase III SELECT BC Trial Evaluating First-Line S-1 Therapy for Metastatic Breast Cancer

Takuya Kawahara; Kojiro Shimozuma; Takeru Shiroiwa; Yasuhiro Hagiwara; Yukari Uemura; T. Watanabe; Naruto Taira; Takashi Fukuda; Yasuo Ohashi; Hirofumi Mukai

Objective: To evaluate the effects of S-1, an orally administered 5-FU agent, versus taxane on patient-reported outcomes (PROs) in the SELECT BC trial. Methods: Patients with HER2-negative and endocrine treatment-resistant breast cancer with metastasis or recurrence after surgery were randomly assigned to receive first-line taxane or S-1. PROs (secondary endpoint) were assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and Patient Neurotoxicity Questionnaire (PNQ) at baseline and at 3, 6, and 12 months. We conducted a responder analysis for the QLQ-C30 and PNQ and created cumulative distribution function (CDF) plots as a sensitivity analysis. Results: The questionnaire response rates were over 80% from 386 patients, who completed at least one baseline questionnaire. S-1 was significantly superior to taxane with respect to 6 scales (physical functioning [p = 0.03], role functioning [p = 0.04], social functioning [p < 0.01], financial difficulties [p = 0.01], global health status [p = 0.02], and constipation [p < 0.01]) and sensory neuropathy (p = 0.01). The CDF plots partially supported the conclusions and their robustness. Conclusion: First-line S-1 therapy has clinical benefits with respect to many aspects of health-related quality of life for metastatic breast cancer patients.


Pediatrics International | 2018

Effect of i.v. immunoglobulin in the first 4 days of illness in Kawasaki disease

Yusuke Shiozawa; Ryo Inuzuka; Takahiro Shindo; Ryo Mafune; Taiyu Hayashi; Yoichiro Hirata; Nobutaka Shimizu; Jun Inatomi; Yoshiki Yokoyama; Yoshiyuki Namai; Yoichiro Oda; Masaru Takamizawa; Yutaka Harita; Takuya Kawahara; Akira Oka

Although early treatment of Kawasaki disease (KD) with i.v. immunoglobulin (IVIG) is expected to prevent coronary artery abnormalities, the effectiveness of IVIG by day 4 of illness remains to be determined.


Journal of Occupational Health | 2018

The impact of night-shift work on platelet function in healthy medical staff

Tomoko Nakao; Atsushi Yasumoto; Suzumi M. Tokuoka; Yoshihiro Kita; Takuya Kawahara; Masao Daimon; Yutaka Yatomi

Rotating shift work has been reported to increase the risk of cardiovascular diseases. Vascular endothelial dysfunction and platelet activation are among the leading causes of thrombus formation in patients with myocardial infarction or stroke. Endothelial function has been shown to be impaired immediately after night‐shift work; however, it is not known whether platelets are also activated. The aim of this study was to investigate the acute impact of night‐shift work on platelet function.


International Journal of Clinical Oncology | 2018

Meta-analysis of randomized clinical trials in the era of individual patient data sharing

Takuya Kawahara; Musashi Fukuda; Koji Oba; Junichi Sakamoto; Marc Buyse

BackgroundIndividual patient data (IPD) meta-analysis is considered to be a gold standard when the results of several randomized trials are combined. Recent initiatives on sharing IPD from clinical trials offer unprecedented opportunities for using such data in IPD meta-analyses.MethodsFirst, we discuss the evidence generated and the benefits obtained by a long-established prospective IPD meta-analysis in early breast cancer. Next, we discuss a data-sharing system that has been adopted by several pharmaceutical sponsors. We review a number of retrospective IPD meta-analyses that have already been proposed using this data-sharing system. Finally, we discuss the role of data sharing in IPD meta-analysis in the future.ResultsTreatment effects can be more reliably estimated in both types of IPD meta-analyses than with summary statistics extracted from published papers. Specifically, with rich covariate information available on each patient, prognostic and predictive factors can be identified or confirmed. Also, when several endpoints are available, surrogate endpoints can be assessed statistically.ConclusionsAlthough there are difficulties in conducting, analyzing, and interpreting retrospective IPD meta-analysis utilizing the currently available data-sharing systems, data sharing will play an important role in IPD meta-analysis in the future.


Frontiers in Neurology | 2018

Noisy Galvanic Vestibular Stimulation Sustainably Improves Posture in Bilateral Vestibulopathy

Chisato Fujimoto; Naoya Egami; Takuya Kawahara; Yukari Uemura; Yoshiharu Yamamoto; Tatsuya Yamasoba; Shinichi Iwasaki

Patients with bilateral vestibulopathy (BV) suffer from persistent postural imbalance, leading to a marked decrease in quality of life and a higher risk of falls. However, so far, the effective treatments for BV are very limited. We examined whether long-term noisy galvanic vestibular stimulation (nGVS) keeps improving body balance after the cessation of the stimulus in BV patients. Thirteen BV patients received nGVS for 30 min with a lower intensity than the intensity at which they feel any cutaneous sensations, and their postural movement was monitored for 6 h after the stimuli. The same session was repeated at 14-day intervals. Stance tasks on two legs were performed with eyes closed. The velocity of the center of pressure (COP) movement, the area enclosed by the COP movement, and the root mean square of the displacement of the COP were measured. The power spectrum of the COP movement was assessed. Subjective improvement of body balance was graded as worsened (−2), slightly worsened (−1), unchanged (0), slightly improved (+1) and improved (+2) in comparison with that without nGVS. In each session, the velocity of the COP movement was significantly improved for 6 h after the stimulus had ceased (P < 0.01). Concomitantly, the mean frequency of the COP power spectrum was significantly reduced in the anterior-posterior axis (P < 0.05). Subjective symptoms of imbalance were improved during the post-stimulation effect (P < 0.05). nGVS leads to an improvement in body balance that lasts for several hours after the end of the stimulus in BV patients with a reduction in the high-frequency components of their postural movement. This trial was registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMINCTR: UMIN000028054).


Burns | 2018

Tracheostomy and mortality in patients with severe burns: A nationwide observational study

Asuka Tsuchiya; Hayato Yamana; Takuya Kawahara; Yusuke Tsutsumi; Hiroki Matsui; Kiyohide Fushimi; Hideo Yasunaga

BACKGROUND Tracheostomy is often performed in patients with severe burns who are undergoing prolonged mechanical ventilation. However, the appropriate timing of tracheostomy and its effect on mortality remain unknown. The aim of this study was to determine whether tracheostomy can reduce mortality in patients with severe burns. METHODS Using the Japanese Diagnosis Procedure Combination database from April 2010 to March 2014, we extracted data on adult patients with severe burns (burn index score of ≥15) who started mechanical ventilation within 3days of admission. We estimated the hazard ratio for 28-day in-hospital mortality associated with tracheotomy performed from day 5 to 28. We adjusted for baseline and time-dependent confounders using inverse probability of treatment weighting methods and fitted a marginal structural Cox proportional hazard model. RESULTS We identified 680 eligible patients (94 in the tracheostomy group, 2289 person-days; 586 in the non-tracheostomy group, 11,197 person-days). Patients who underwent a tracheostomy had worse prognostic factors for mortality. After adjustment for these factors, the hazard ratio for 28-day mortality associated with tracheostomy compared with non-tracheostomy was 0.73 (95% confidence interval, 0.39-1.34). CONCLUSIONS There was no significant association between 28-day in-hospital mortality and early tracheostomy in adult patients with severe burns.


PharmacoEconomics | 2018

Impact of Adverse Events on Health Utility and Health-Related Quality of Life in Patients Receiving First-Line Chemotherapy for Metastatic Breast Cancer: Results from the SELECT BC Study

Yasuhiro Hagiwara; Takeru Shiroiwa; Kojiro Shimozuma; Takuya Kawahara; Yukari Uemura; Takanori Watanabe; Naruto Taira; Takashi Fukuda; Yasuo Ohashi; Hirofumi Mukai


BMC Cancer | 2017

Cost-effectiveness analysis of the introduction of S-1 therapy for first-line metastatic breast cancer treatment in Japan: results from the randomized phase III SELECT BC trial

Takeru Shiroiwa; Takashi Fukuda; Kojiro Shimozuma; Mitsuko Mouri; Yasuhiro Hagiwara; Takuya Kawahara; Shozo Ohsumi; Yasuo Hozumi; Yoshiaki Sagara; Yasuo Ohashi; Hirofumi Mukai

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Takanori Watanabe

Fukushima Medical University

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