Best practice management of patients with chronic obstructive pulmonary disease: A case-based review

This is the final version. Available from Elsevier via the DOI in this record. Chronic obstructive pulmonary disease (COPD) is associated with a high clinical and economic burden and is the fourth leading cause of death in the United States. The management of patients with COPD aims to minimize and control symptoms, prevent exacerbations, and improve quality of life. We provide an illustrated case study of a female patient with typical progression of COPD and describe the diagnosis, assessment, and management strategy, referring to the evidence seen in recent studies that supports the treatment decisions.GlaxoSmithKlineGlaxoSmithKlineNational Institute of HealthNational Heart, Lung and Blood Institut

On the statistics of the ratio of nonconstrained arbitrary α ‐ μ random variables:a general framework and applications

Abstract In this paper, we derive closed‐form exact expressions for the main statistics of the ratio of two squared α‐μ random variables, which are of interest in many scenarios for future wireless networks where generalized distributions are more suitable to fit with field data. Importantly, different from previous proposals, our expressions are general in the sense that are valid for nonconstrained arbitrary values of the parameters of the α‐μ distribution. Thus, the probability density function, cumulative distribution function, moment generating function, and higher‐order moments are given in terms of both (i) the Fox H‐function for which we provide a portable and efficient Wolfram Mathematica code and (ii) easily computable series expansions. Our expressions can be used straightforwardly in the performance analysis of a number of wireless communication systems, including either interference‐limited scenarios, spectrum sharing, full‐duplex, or physical‐layer security networks, for which we present the application of the proposed framework. Moreover, closed‐form expressions for some classical distributions, derived as special cases from the α‐μ distribution, are provided as byproducts. The validity of the proposed expressions is confirmed via Monte Carlo simulations

The Long-Term Oxygen Treatment Trial for Chronic Obstructive Pulmonary Disease: Rationale, Design, and Lessons Learned

The Long-Term Oxygen Treatment Trial demonstrated that long-term supplemental oxygen did not reduce time to hospital admission or death for patients who have stable chronic obstructive pulmonary disease and resting and/or exercise-induced moderate oxyhemoglobin desaturation, nor did it provide benefit for any other outcome measured in the trial. Nine months after initiation of patient screening, after randomization of 34 patients to treatment, a trial design amendment broadened the eligible population, expanded the primary outcome, and reduced the goal sample size. Within a few years, the protocol underwent minor modifications, and a second trial design amendment lowered the required sample size because of lower than expected treatment group crossover rates. After 5.5 years of recruitment, the trial met its amended sample size goal, and 1 year later, it achieved its follow-up goal. The process of publishing the trial results brought renewed scrutiny of the study design and the amendments. This article expands on the previously published design and methods information, provides the rationale for the amendments, and gives insight into the investigators' decisions about trial conduct. The story of the Long-Term Oxygen Treatment Trial may assist investigators in future trials, especially those that seek to assess the efficacy and safety of long-term oxygen therapy. Clinical trial registered with clinicaltrials.gov (NCT00692198)