<qa>  What is the current inpatient NIV initiation process?First, the current inpatient NIV initiation process has to be reconsidered, which despite tight titration based on arterial blood gases, does not always lead to good patient compliance, is inconvenient for patients and is expensive. While it might be thought that high-intensity NIV necessitates inpatient titration to gain adequate reversal of hypoventilation, different in hospital set ups of NIV initiation on a general ward, medium care unit or on an intensive care unit, with different ways of titration guided by transcutaneous carbon dioxide PtCO2 or arterial blood gases PaCO2, have not resulted in different outcomes or a different compliance at the long-term. Also, these inpatient options are expensive as initiation of NIV in COPD routinely requires 5-14 days. Recently, our group of the HMV centre Groningen has shown that, in patients with neuromuscular and restrictive thoracic diseases, initiation of NIV can safely be performed at home. Initiation of NIV at home was preferred by the patients, was equally effective and saved costs compared to inpatient initiation. Importantly, COPD patients have been excluded in this randomised controlled trial RCT, as at the start of that study chronic NIV in COPD was not considered a regular standard treatment option in the Netherlands. Furthermore, initiation of NIV in COPD patients at that time was thought to be probably too difficult to be performed at home, because high-intensity NIV is needed in this patient group to improve outcomes. 