FIG. 31: Those patients who were initially randomized to HOT alone were allowed acute NIV during exacerbations, with the aim of weaning them from NIV acutely and discharging them back to their allocated treatment arm of HOT alone.[1] However, home NIV was allowed to be added in these patients after they had attained the primary outcome, ie, they had been readmitted to hospital if they had reached a number of safety criteria as defined a priori in the trial protocol.