Ambulatory Long-Term Oxygen Therapy in Patients with Severe COPD: A Randomized Crossover Trial to Compare Constant-Minute-Volume and Constant-Bolus Systems.

"Disclosure The Cologne study group (F.S.M., D.K., M.Z., S.B.S., D.S.M., M.WS and W.W.) received an open research grant from Weinmann/Germany, Vivisol/Germany, Heinen und Löwenstein/Germany, GCE Ltd. UK and VitalAire/Germany Philips Respironics/Netherlands and Löwenstein Medical/Germany. F.S.M., and S.B.S. received personal travel grants from companies dealing with LTOT. W.W. received speaking fees from companies dealing with LTOT. MZ reports personal fees from Resmed, outside the submitted work. The authors report no other conflicts of interest in this work."

"A research grant was provided by GCE Healthcare (Malmö, Sweden). The authors state that neither the study design, results, interpretation of the findings, nor any other subject discussed in the submitted manuscript was dependent on financial support."

"This trial was designed as a crossover randomized trial. The study protocol was approved by the Ethics Committee at Witten/Herdecke University, Witten, Germany, and was undertaken at the Department of Pneumology, Lung Clinic, Cologne Merheim Hospital, Witten/Herdecke University, Germany, as well as the Department of Pneumology, Augustinerinnen Hospital, Cologne, Germany. The study was performed in accordance with the ethical standards laid down in the Declaration of Helsinki. The study was registered at the German Clinical Trials Register (DRKS00017000). Informed written consent was obtained from all subjects."