Baseline characteristics of patients
| Variable | Direct discontinuation (n=59) | Nocturnal NIV (n=61) | p-value |
| Age years | 71 (61–78) | 71 (61–78) | 0.87 |
| Male/female | 39/20 | 41/20 | 0.90 |
| FEV1 % pred# | 35 (28–45) | 38 (30–49) | 0.33 |
| Other comorbidities | |||
| Chronic heart disorders¶ | 24 (41) | 24 (39) | 0.88 |
| Immunosuppression+ | 2 (3) | 5 (8) | 0.44 |
| Diabetes mellitus | 11 (19) | 13 (21) | 0.72 |
| Solid cancer | 2 (3) | 7 (12) | 0.093 |
| Chronic liver disorders | 3 (5) | 6 (10) | 0.32 |
| Chronic renal failure | 0 (0) | 2 (3) | 0.16 |
| Morbid obesity§ | 9 (15) | 13 (21) | 0.39 |
| Main cause of COPD exacerbation | 0.52 | ||
| Infection | 32 (54) | 28 (46) | |
| Undetermined | 24 (41) | 31 (51) | |
| Cardiac | 3 (5) | 2 (3) | |
| APACHE-II on admission | 18 (14–20) | 17 (15–21) | 0.81 |
Data are presented as n, n (%) or median (interquartile range). NIV: noninvasive ventilation; FEV1: forced expiratory volume in 1 s; COPD: chronic obstructive pulmonary disease; APACHE II: Acute Physiology and Chronic Health Evaluation II. #: this information was available in 38 patients from the direct discontinuation group and 48 from the nocturnal NIV group; ¶: chronic heart disorders include coronary artery disease, hypertensive or valvular heart diseases, and dilated myocardial disease of any cause; +: immunosuppression includes neutropenia after chemotherapy or bone marrow transplant, drug-induced immunosuppression in solid organ transplant or as a result of corticosteroids or cytotoxic therapy, and human immunodeficiency virus-related disorders; §: morbid obesity (body mass index ≥40 kg·m−2) information was obtained from the patients' medical records and/or the most recent forced spirometry reports.