The principal clinical characteristics of the children enrolled in the study
| Number of patients | 90, female 45 (50%), male 45 (50%) |
| Patient age range | Median 8.8 years, IQR 2.6–15.1 years, range 0.4–17.8 years |
| Time on ventilatory support | Median 3.4 years, IQR 1.4–8.4 years, range 0.2–16.7 years |
| Schooling | Full-time school: 42 (46.7%) Part-time or home school: 16 (17.8%) Too young for school: 32 (35.5%) |
| Diagnostic group | Airway obstruction: 29 (32.2%) Chronic lung disease: 25 (27.8%) Neuromuscular disease: 24 (26.6%) Central hypoventilation: 7 (7.8%) Spinal cord injury: 5 (5.6%) |
| Type of support | Tracheostomy alone: 15 (16.7%) Tracheostomy plus ventilation: 13 (14.4%) BiPAP: 40 (44.5%) CPAP: 22 (24.4%) |
| Daily ventilation | Tracheostomy alone: 0 h Tracheostomy–ventilation: median 11.0 h, range 9–24 h BiPAP: median 10 h, IQR 8.5–12 h, range 4–18 h CPAP: median 9 h, IQR 8.5–10 h, range 6–12 h |
Single values are expressed as numbers plus percentages of the total in brackets. All variables were non-normally distributed so average values and dispersion are expressed as median plus IQR and full range.
BiPAP, bilevel positive airway pressure; CPAP, continuous positive airway pressure.