Likelihood Ratio Tests and Intersection-Union Tests

The likelihood ratio test (LRT) method is a commonly used method of hypothesis test construction. The intersection-union test (IUT) method is a less commonly used method. We will explore some relationships between these two methods. We show that, under some conditions, both methods yield the same test. But, we also describe conditions under which the size-ff IUT is uniformly more powerful than the size-ff LRT. We illustrate these relationships by considering the problem of testing H 0 : minfj 1 j; j 2 jg = 0 versus H a : minfj 1 j; j 2 jg ? 0, where 1 and 2 are means of two normal populations

Development of a nomogram for predicting in-hospital mortality of patients with exacerbation of chronic obstructive pulmonary disease

Yukiyo Sakamoto,1 Yasuhiro Yamauchi,1 Hideo Yasunaga,2 Hideyuki Takeshima,1 Wakae Hasegawa,1 Taisuke Jo,1,3 Yusuke Sasabuchi,3 Hiroki Matsui,2 Kiyohide Fushimi,4 Takahide Nagase1 1Department of Respiratory Medicine, Graduate School of Medicine, 2Department of Clinical Epidemiology and Health Economics, School of Public Health, 3Department of Health Services Research, Graduate School of Medicine, University of Tokyo, 4Department of Health Policy and Informatics, Graduate School of Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan Background and objectives: Patients with chronic obstructive pulmonary disease (COPD) often experience exacerbations of their disease, sometimes requiring hospital admission and being associated with increased mortality. Although previous studies have reported mortality from exacerbations of COPD, there is limited information about prediction of individual in-hospital mortality. We therefore aimed to use data from a nationwide inpatient database in Japan to generate a nomogram for predicting in-hospital mortality from patients’ characteristics on admission.Methods: We retrospectively collected data on patients with COPD who had been admitted for exacerbations and been discharged between July 1, 2010 and March 31, 2013. We performed multivariable logistic regression analysis to examine factors associated with in-hospital mortality and thereafter used these factors to develop a nomogram for predicting in-hospital prognosis.Results: The study comprised 3,064 eligible patients. In-hospital death occurred in 209 patients (6.8%). Higher mortality was associated with older age, being male, lower body mass index, disturbance of consciousness, severe dyspnea, history of mechanical ventilation, pneumonia, and having no asthma on admission. We developed a nomogram based on these variables to predict in-hospital mortality. The concordance index of the nomogram was 0.775. Internal validation was performed by a bootstrap method with 50 resamples, and calibration plots were found to be well fitted to predict in-hospital mortality.Conclusion: We developed a nomogram for predicting in-hospital mortality of exacerbations of COPD. This nomogram could help clinicians to predict risk of in-hospital mortality in individual patients with COPD exacerbation. Keywords: chronic obstructive pulmonary disease, exacerbation, in-hospital mortality, nomogra

Reduction in exacerbation of COPD in patients of advanced age using the Japanese Kampo medicine Dai-kenchu-to: a retrospective cohort study

Taisuke Jo,1,2 Nobuaki Michihata,1 Hayato Yamana,1 Yusuke Sasabuchi,3 Hiroki Matsui,4 Hirokazu Urushiyama,2 Akihisa Mitani,2 Yasuhiro Yamauchi,2 Kiyohide Fushimi,5 Takahide Nagase,2 Hideo Yasunaga4 1Department of Health Services Research, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; 2Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; 3Data Science Center, Jichi Medical University, Tochigi, Japan; 4Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan; 5Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan Purpose: Patients with symptomatic COPD are recommended to use inhaled bronchodilators containing long-acting muscarinic receptor antagonists (LAMAs). However, bronchodilators may cause gastrointestinal adverse effects due to anticholinergic reactions, especially in advanced-age patients with COPD. Dai-kenchu-to (TU-100, Da Jian Zhong Tang in Chinese) is the most frequently prescribed Japanese herbal Kampo medicine and is often prescribed to control abdominal bloating and constipation. The purpose of this study was to evaluate the role of Dai-kenchu-to as a supportive therapy in advanced-age patients with COPD. Patients and methods: We used the Japanese Diagnosis Procedure Combination inpatient database and identified patients aged ≥75 years who were hospitalized for COPD exacerbation. We then compared the risk of re-hospitalization for COPD exacerbation or death between patients with and without Dai-kenchu-to using 1-to-4 propensity score matching. A Cox proportional hazards model was used to compare the two groups. We performed subgroup analyses for patients with and without LAMA therapy. Results: Patients treated with Dai-kenchu-to had a significantly lower risk of re-hospitalization or death after discharge; the HR was 0.82 (95% CI, 0.67–0.99) in 1-to-4 propensity score matching. Subgroup analysis of LAMA users showed a significant difference in re-hospitalization or death, while subgroup analysis of LAMA non-users showed no significant difference. Conclusion: Our findings indicate that Dai-kenchu-to may have improved the tolerability of LAMA in advanced-age patients with COPD and, therefore, reduced the risk of re-hospitalization or death from COPD exacerbation. Dai-kenchu-to may be recommended as a useful supportive therapy for advanced-age patients with COPD. Keywords: TU-100, herbal medicine, muscarinic receptor antagonists, propensity score, survival analysi