Home noninvasive positive pressure ventilation with built-in software in stable hypercapnic COPD: a short-term prospective, multicenter, randomized, controlled trial.
COPD assessment test (CAT) showed a positive trend ( P =0.06) in favor of the NPPV group.
also in 11,005 other papers
Quoted from the open-access full text in Europe PMC under the licence the publisher applied. The sentence is reproduced exactly as published; the emphasis is ours.