Table 3.

Survival from baseline sleep studies (time point T1)

Parameter	NIV status	Stratification	n	Mean survival (months)	Median survival (months)	p
AHI	NIV(+)	< 5/h	40	22.1 (20.7)	17.9 (0.5–99.2)	n.s.
		≥ 5/h	55	25.1 (20.3)	17.5 (2.4–97.3)
	NIV(–)	< 5/h	38	22.7 (17.5)	19.5 (2.3–89.3)	0.027
		≥ 5/h	25	14.8 (12.8)	12.9 (0.7–46.3)
max. ptcCO2	NIV(+)	< 50 mmHg	59	26.2 (23.1)	19.5 (0.5–99.2)	n.s.
		≥ 50 mmHg	36	20.0 (14.6)	16.9 (3.0–60.7)
	NIV(–)	< 50 mmHg	59	20.4 (16.4)	15.7 (0.7–89.3)	0.025
		≥ 50 mmHg	4	7.3 (1.9)	7.3 (5.1–9.7)
$t_{{\text{CO}}_2}$  ≥ 50	NIV(+)	< 30 min	72	24.1 (20.2)	19.1 (0.5–97.3)	n.s.
		≥ 30 min	17	20.4 (13.9)	16.9 (4.4–52.6)
	NIV(–)	< 30 min	63	19.6 (16.1)	14.9 (0.7–89.3)	–
		≥ 30 min	0
EMBE	NIV(+)	≤ 2 mmol/l	36	28.4 (23.4)	20.5 (2.4–97.3)	n.s.
		> 2 mmol/l	52	18.3 (11.5)	16.6 (0.5–48.1)
	NIV(–)	≤ 2 mmol/l	30	26.5 (17.9)	24.5 (1.4–89.3)	< 0.001
		> 2 mmol/l	28	13.0 (11.1)	10.8 (1.8–56.4)
upright FVC	NIV(+)	≥ 70% pred	25	28.7 (20.8)	26.2 (2.4–78.5)	n.s.
		< 70% pred	35	22.3 (21.7)	16.9 (0.5–99.2)
	NIV(−)	≥ 70% pred	26	23.4 (20.7)	18.8 (2.3–89.3)	n.s.
		< 70% pred	11	19.5 (13.0)	16.1 (1.8–46.3)

Patients were stratified according to baseline respiratory sleep outcomes (using specific cut-off values) and NIV status. Mean survival is depicted in column 5, with standard deviation in brackets. Median survival is shown in column 6 (with range in brackets)

AHI apnea hypopnea index, p_tcCO₂ maximum transcutaneous carbon dioxide tension, $t_{{\text{CO}}_2}$  ≥ 50 cumulative duration of nocturnal hypercapnia ≥ 50 mmHg, EMBE early morning base excess, FVC forced vital capacity, NIV non-invasive ventilation

p values in the last column refer to the Mann–Whitney U test