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Featured researches published by Ryota Kojima.


Respirology | 2013

Sensitivity and specificity of the Streptococcus pneumoniae urinary antigen test for unconcentrated urine from adult patients with pneumonia: A meta‐analysis

Nobuyuki Horita; Naoki Miyazawa; Ryota Kojima; Naoko Kimura; Miyo Inoue; Yoshiaki Ishigatsubo; Takeshi Kaneko

Studies on the sensitivity and specificity of the Binax Now Streptococcus pneumonia urinary antigen test (index test) show considerable variance of results. Those written in English provided sufficient original data to evaluate the sensitivity and specificity of the index test using unconcentrated urine to identify S. pneumoniae infection in adults with pneumonia. Reference tests were conducted with at least one culture and/or smear. We estimated sensitivity and two specificities. One was the specificity evaluated using only patients with pneumonia of identified other aetiologies (‘specificity (other)’). The other was the specificity evaluated based on both patients with pneumonia of unknown aetiology and those with pneumonia of other aetiologies (‘specificity (unknown and other)’) using a fixed model for meta‐analysis. We found 10 articles involving 2315 patients. The analysis of 10 studies involving 399 patients yielded a pooled sensitivity of 0.75 (95% confidence interval: 0.71–0.79) without heterogeneity or publication bias. The analysis of six studies involving 258 patients yielded a pooled specificity (other) of 0.95 (95% confidence interval: 0.92–0.98) without no heterogeneity or publication bias. We attempted to conduct a meta‐analysis with the 10 studies involving 1916 patients to estimate specificity (unknown and other), but it remained unclear due to moderate heterogeneity and possible publication bias. In our meta‐analysis, sensitivity of the index test was moderate and specificity (other) was high; however, the specificity (unknown and other) remained unclear.


Respiratory Research | 2014

Statins reduce all-cause mortality in chronic obstructive pulmonary disease: a systematic review and meta-analysis of observational studies

Nobuyuki Horita; Naoki Miyazawa; Ryota Kojima; Miyo Inoue; Yoshiaki Ishigatsubo; Atsuhisa Ueda; Takeshi Kaneko

BackgroundRecent observational studies have suggested that use of statins reduces mortality in patients suffering from chronic obstructive pulmonary disease. However, no meta-analysis has reported the pooled hazard ratio of statins to all-cause mortality.MethodsWe searched for eligible articles using five databases. We included randomized controlled trials and cohort studies written in English using original data reporting the hazard ratio of statins to all-cause, cardiovascular-related, cancer-related, or respiratory-related mortality. A fixed model with the confidence interval method was used. Publication bias was evaluated by funnel plot and Begg’s test, and was corrected using Duval’s trim and fill method. Sensitivity analyses were also conducted.ResultsWe included 10 out of 128 articles. The pooled hazard ratio of statins to all-cause mortality involving 16269 patients was 0.81 (95% CI: 0.75-0.86, P < 0.001) with moderate heterogeneity (I2 = 52%, P = 0.032). The sensitivity analysis and funnel plot suggested the existence of publication bias. After three possibly unpublished cohorts were imputed, the pooled hazard ratio of 0.83 (95% CI: 0.78-0.88, P < 0.001) still suggested a favorable prognosis in statin-treated patients. The pooled hazard ratio of statins to cardiovascular-related, cancer-related, and respiratory-related mortality were 0.52 (95% CI: 0.27-1.01, P = 0.052), 0.57 (95% CI: 0.32-1.01, P = 0.056), and 0.55 (95% CI: 0.43-0.78, P < 0.001), respectively, although these results were not conclusive as we could not find a sufficient number of original studies dealing with those forms of mortality.ConclusionsThe use of statins for patients suffering from chronic obstructive pulmonary disease may reduce all-cause mortality. This conclusion should be re-evaluated by a registered large-scale randomized controlled trial.


Respiratory Research | 2013

Long-acting beta-agonists reduce mortality of patients with severe and very severe chronic obstructive pulmonary disease: a propensity score matching study

Nobuyuki Horita; Naoki Miyazawa; Satoshi Morita; Ryota Kojima; Naoko Kimura; Takeshi Kaneko; Yoshiaki Ishigatsubo

BackgroundLong-acting beta-agonists were one of the first-choice bronchodilator agents for stable chronic obstructive pulmonary disease. But the impact of long-acting beta-agonists on mortality was not well investigated.MethodsNational Emphysema Treatment Trial provided the data. Severe and very severe stable chronic obstructive pulmonary disease patients who were eligible for volume reduction surgery were recruited at 17 clinical centers in United States during 1988–2002. We used the 6–10 year follow-up data of patients randomized to non-surgery treatment. Hazard ratios for death by long-acting beta-agonists were estimated by three models using Cox proportional hazard analysis and propensity score matching were measured.ResultsThe pre-matching cohort was comprised of 591 patients (50.6% were administered long-acting beta-agonists. Age: 66.6 ± 5.3 year old. Female: 35.4%. Forced expiratory volume in one second (%predicted): 26.7 ± 7.1%. Mortality during follow-up: 70.2%). Hazard ratio using a multivariate Cox model in the pre-matching cohort was 0.77 (P = 0.010). Propensity score matching was conducted (C-statics: 0.62. No parameter differed between cohorts). The propensity-matched cohort was comprised of 492 patients (50.0% were administered long-acting beta-agonists. Age: 66.8 ± 5.1 year old. Female: 34.8%. Forced expiratory volume in one second (%predicted) 26.5 ± 6.8%. Mortality during follow-up: 69.1%). Hazard ratio using a univariate Cox model in the propensity-matched cohort was 0.77 (P = 0.017). Hazard ratio using a multivariate Cox model in the propensity-matched cohort was 0.76 (P = 0.011).ConclusionsLong-acting beta-agonists reduce mortality of severe and very severe chronic obstructive pulmonary disease patients.


Archivos De Bronconeumologia | 2016

Uso crónico de teofilina y mortalidad en la enfermedad pulmonar obstructiva crónica: un metaanálisis

Nobuyuki Horita; Naoki Miyazawa; Ryota Kojima; Miyo Inoue; Yoshiaki Ishigatsubo; Takeshi Kaneko

BACKGROUND Theophylline has been shown to improve respiratory function and oxygenation in patients with chronic obstruction pulmonary disease (COPD). However, the impact of theophylline on mortality in COPD patients has not been not sufficiently evaluated. METHOD Two investigators independently searched for eligible articles in 4 databases. The eligibility criterion for this meta-analysis was an original research article that provided a hazard ratio for theophylline for all-cause mortality of COPD patients. Both randomized controlled trials and observational studies were accepted. After we confirmed no substantial heterogeneity (I(2)<50%), the fixed-model method with generic inverse variance was used for meta-analysis to estimate the pooled hazard ratio. RESULTS We screened 364 potentially eligible articles. Of the 364 articles, 259 were excluded on the basis of title and abstract, and 99 were excluded after examination of the full text. Our final analysis included 6 observational studies and no randomized controlled trials. One study reported 2 cohorts. The number of patients in each cohort ranged from 47 to 46,403. Heterogeneity (I(2)=42%, P=.11) and publication bias (Beggs test r=0.21, P=.662) were not substantial. Fixed-model meta-analysis yielded a pooled hazard ratio for theophylline for all-cause death of 1.07 (95% confidence interval: 1.02-1.13, P=.003). CONCLUSION This meta-analysis of 7 observational cohorts suggests that theophylline slightly increases all-cause death in COPD patients.


Respiratory investigation | 2014

Three cases of mesalazine-induced pneumonitis with eosinophilia

Miyo Inoue; Nobuyuki Horita; Naoko Kimura; Ryota Kojima; Naoki Miyazawa

Oral mesalazine, or 5-aminosalicylate, is one of the first-choice medications for the treatment of ulcerative colitis and is commonly used for both induction and maintenance therapy. In a 6-month period, we treated three cases of mesalazine-induced pneumonitis. In all three cases, computed tomography images revealed upper lobe dominant bilateral peripherally localized consolidations. Such images are commonly observed in patients with cryptogenic organizing pneumonia or chronic eosinophilic pneumonia. Computed tomography images for mesalazine-induced pneumonitis have been rarely reported in the literature.


COPD: Journal of Chronic Obstructive Pulmonary Disease | 2014

Small, moderate, and large changes, and the minimum clinically important difference in the University of California, San Diego Shortness of Breath Questionnaire.

Nobuyuki Horita; Naoki Miyazawa; Satoshi Morita; Ryota Kojima; Naoko Kimura; Takeshi Kaneko; Yoshiaki Ishigatsubo

Abstract Minimum clinically important change of 5 points in the University of California, San Diego Shortness of Breath Questionnaire (SOBQ) is established, but cutoff values between a small, a moderate, and a large change are still unknown. We used the data set of National Emphysema Treatment Trial consisting of severe and very severe chronic obstructive pulmonary disease patients, whose mean age was 64 years. Changes from baseline to post-surgical 6-month follow-up were evaluated. The St. Georges Respiratory Questionnaire was used as anchor: |∆SGRQ| < 4, meaningless change; 4 ≤ |∆SGRQ| < 8, small change; 8 ≤ |∆SGRQ| < 13, moderate change; 13 ≤ |∆SGRQ|, large change. We decided the final cutoff values for the SOBQ as medians of the three anchor methods. We also decided the range of cutoff values as the range of three values. In a cohort of surgically treated patients (N = 484), we propose value of 5 (range 5–6), 11 (range 9–15), and 16 (range 14–20) for the cutoff values between a meaningless and a small change (minimum clinically important difference), a small and a moderate change, and a moderate and a large change, respectively. In a cohort of medically treated patients, numbers of patients categorized according to ∆SOBQ scores were similar to those of the patients categorizes according to the ∆SGRQ (N = 480) or ∆Forced expiratory volume in 1 second (N = 425). We propose group-level cutoff values and range between a small, a moderate, and a large changes.


Transactions of The Royal Society of Tropical Medicine and Hygiene | 2013

Poor performance status is a strong predictor for death in patients with smear-positive pulmonary TB admitted to two Japanese hospitals

Nobuyuki Horita; Naoki Miyazawa; Takashi Yoshiyama; Ryota Kojima; Naoko Omori; Takeshi Kaneko; Yoshiaki Ishigatsubo

BACKGROUND Estimation of performance status (PS) has been assessed as a tool to determine which patients with newly diagnosed pulmonary TB (PTB) are most at risk of dying. This simple prediction rule has not been validated in patients with PTB with different background characteristics and from different geographic areas. METHODS A retrospective cohort study was conducted in two Japanese hospitals in different regions and included 432 inpatients with newly diagnosed smear-positive non-multidrug-resistant lung TB without HIV infection. The patients had a mean ± SD age of 64.9 ± 19.7 years and 135 were female (31.3%). Detailed nursing charts were reviewed to estimate PS, which was graded 0 (best condition), 1, 2, 3 or 4 (worst condition), for each patient. RESULTS Single variable and multivariable Cox regression analyses models revealed that a one-point increase in PS was associated with a 2.8-fold (95% CI 2.2-3.6) and 2.3-fold (95% CI 1.8-3.0), adjusted for age, gender, comorbidities and treatment regimen, increase in the HR for death (p < 0.001 for both models). Kaplan-Meier curves also showed a significant difference in mortality among different PS groups (p < 0.001). CONCLUSION PS was strongly associated with mortality from PTB in the study cohort. Estimation of PS at the start of treatment for newly diagnosed PTB patients could be a useful tool in case management in resource-limited countries.


COPD: Journal of Chronic Obstructive Pulmonary Disease | 2015

Minimum Clinically Important Difference in Diffusing Capacity of the Lungs for Carbon Monoxide Among Patients with Severe and Very Severe Chronic Obstructive Pulmonary Disease

Nobuyuki Horita; Naoki Miyazawa; Ryota Kojima; Miyo Inoue; Yoshiaki Ishigatsubo; Takeshi Kaneko

Abstract Background: The minimum clinically important difference (MCID) for diffusing capacity of the lungs for carbon monoxide (DLCO) has not yet been solidly established. Methods: We used the dataset of surgical cohort of National Emphysema Treatment Trial. Briefly, severe and very severe chronic obstructive pulmonary disease (COPD) patients who were candidate for volume reduction surgery and who could provide sufficient data at 12-month follow-up were included. We used two anchor methods using 6-minute walk distance (6MWD. MCID = 40 m) and forced expiratory volume in 1 sec (FEV1. MCID = 100 ml) as anchors, and two distribution methods. We proposed MCID with a median of estimated values. We estimated MCID for DLCO in raw value and % change from the baseline independently. Results: The surgical cohort included 356 patients, whose average age was 66.6 ± 5.5 years, and the average % predicted FEV1 was 27.8 ± 7.3%. The estimated MCID for DLCO in raw value and % change from the baseline were as follows: anchor method (average, 6MWD) 1.2 ml/min/mmHg, 17%; anchor method (average, FEV1) 0.7 ml/min/mmHg, 11%; anchor method (receiver operating characteristic, 6MWD) 1.1 ml/min/mmHg, 10%; anchor method (receiver operating characteristic, FEV1) 1.2 ml/min/mmHg, 3%; distribution method (0.3 units of standard deviation), 0.9 ml/min/mmHg, 11%; distribution method (standard error of measurement), 1.1 ml/min/mmHg. The median of these values was 1.1 ml/min/mmHg and 11%. Conclusion: We estimated the group-level MCID for DLCO for patients with severe and very severe COPD patients as 1.1 ml/min/mmHg and 11% of baseline DLCO.


Internal Medicine | 2015

Currently Used Low-Dose Pyrazinamide Does Not Increase Liver-Injury in the First Two Months of Tuberculosis Treatment

Nobuyuki Horita; Naoki Miyazawa; Takashi Yoshiyama; Ryota Kojima; Yoshiaki Ishigatsubo; Takeshi Kaneko

OBJECTIVE In the 1950s, a high-dose (40-70 mg/kg/day) of pyrazinamide (PZA), was reported to cause drug-induced liver injury (DILI) at an unacceptable frequency. It remains unclear whether adding PZA (Z) at the currently accepted low-dose (20-25 mg/kg/day) for two months to a regimen of isoniazid (H) + rifampicin (R) + ethambutol (E) actually increases the risk of DILI. METHOD Smear-positive tuberculosis patients were treated with daily HRE or HRZE regimen under direct observation. We used three independent models. Model 1 was analyzed with a multivariate Cox-analysis using a pre-matched cohort. Next, propensity score matching was conducted using the nearest neighbor method with caliper of 0.03. Models 2 and 3 were analyzed by univariate and multivariate Cox-analyses, respectively, with the matched cohort. DILI was assessed based on the guidelines of the American Thoracic Society. RESULTS We reviewed the records of 383 patents (male, n=260; female n=123; mean age, 64±20 years). Among these patients, 75 patients were treated with HRE and 308 were treated with HRZE. DILI occurred in the first two months in 24% (18/75) and 8% (24/308) of the HRE-treated and HRZE-treated cases, respectively. In all three of the models, DILI was less frequent in patients treated with the HRZE regimen: Model 1, HR of 0.30 (95% confidence interval (CI) 0.14-0.68, p=0.004); Model 2, HR of 0.37 (95%CI 0.14-0.96, p=0.041); and Model 3, HR of 0.34 (95%CI 0.12-0.94, p=0.038). CONCLUSION The addition of the currently accepted low dose (20-25 mg/kg/day) of PZA to the HRE regimen did not increase the incidence of DILI during the first two months of treatment.


Internal Medicine | 2015

Impact of Corticosteroids on Mortality in Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-analysis.

Nobuyuki Horita; Satoru Hashimoto; Naoki Miyazawa; Hiroyuki Fujita; Ryota Kojima; Miyo Inoue; Atsuhisa Ueda; Yoshiaki Ishigatsubo; Takeshi Kaneko

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Naoki Miyazawa

Yokohama City University

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Takeshi Kaneko

Yokohama City University

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Miyo Inoue

Yokohama City University

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Atsuhisa Ueda

Yokohama City University

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Satoru Hashimoto

Kyoto Prefectural University of Medicine

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