Limited data are available about the prognosis and its predictive factors in patients with chronic respiratory failure receiving domiciliary NPPV. In addition, their health status, psychological status and sleep quality seem to be highly disturbed due to severe respiratory insufficiency. Therefore, in the present study, we aim to examine (1) contributive factors to health status based on baseline data, (2) whether patient reported measurements such as health status, dyspnea and psychological status would predict patient's future outcomes, and (3) how they would change for 3 years as compared to physiological measurements.