Table 1

Patient characteristics

nGroup O−n=92)nGroup O+(n=87)p Value
Anthropometric data
 Age (years)9264.6 [57.3–71.9]8763.6 [57.1–72.1]NS
 Gender (number of men—%)4055 [60%]4158 [67%]NS
 Body mass index (kg/m2)9023.1 [19.6–25.9]8721.8 [19.1–25.0]NS
 Smoking greater than 20 pack-years (number of patients—%)380 [0–10]400 [0–10]NS
Neurological assessment
 Time from onset to diagnostic (months)929 [5–17]8612[6–16]NS
 Time from onset to NIV (months)6824[11–39]6422 [13–35]NS
 ALSFRS-R score (/48)8540 [35–43]8540 [36–43]NS
 Bulbar onset (n—%)8924 (27)8612 (14)0.03
 Norris bulbar score (/39)7236 [31–39]8438 [32–39]NS
 Gastrostomy in the follow-up (number of patients-%)9221 (23%)879 (10%)0.02
Respiratory assessment
 VC sitting/supine (L)58/631.46[0.92–2.05]
1.02 [0.54–1.65]
65/621.44 [1.12–2.05]
1.01 [0.77–1.53]
NS
 VC sitting/supine (% predicted)58/6340.5 [31–54]
39.5 [28–52]
65/6239 [32–53]
33 [27–46]
NS
 PiMAX (cm H2O and % predicted)6621 [12–31] and
21 [12–34]
6024 [13–55] and 25 [14–55]NS
 SNIP (cm H2O and % predicted)6819 [12–26] and
19 [13–28]
5920 [14–36] and 24 [16–36]0.04
 Cough peak flow (L/mn)81160 [110–250]66120 [70–200]NS
 pH before NIV/on NIV617.41 [7.39–7.43]
7.42 [7.41–7.43]
737.41 [7.40–7.43]
7.41 [7.40–7.43]
NS
 PaCO2 before NIV/on NIV (mm Hg)91/8748 [43–52]
43 [41–48]
85/8749 [46–55]
50 [44–55]
NS
<0.001
 deltaPaCO2 (mm Hg)864 [11–10]851 [11–10]NS
 PaO2 before NIV/on NIV (mm Hg)60/8773 [67–82]
78 [70–85]
72/8775 [68–82]
78 [72–86]
NS
NS
 TS90 before NIV/on NIV (% of recording)77/8430 [11–75]
0 [0–5]
64/7924 [7–66]
7 [1–17]
NS
<0.001
Non-invasive ventilation parameters
 IPAP (cm H2O)9213 [12–14]8713 [12–15]NS
 EPAP (cm H2O)924 [4–4]874 [4–6]0.01
 RR (/min)9116 [14–16]8616 [14–16]NS
 NIV use (hours per day)8710 [8–14]848 [6–10]<0.001
 Estimated Vt786440 [390–510]84417 [355–472]0.04
 Leaks (L/min)861 [0–16]841 [0–6]NS
 Face mask (n—%)9175[69–82]8775 [68–80]NS
  • Results are expressed as median [IQR].ALSFRS-R, revised Amyotrophic Lateral Sclerosis—Functional Rating Scale; EPAP, expiratory positive airway pressure; IPAP, inspiratory positive airway pressure; NIV, non-invasive ventilation; NS, not significant; PaCO2, arterial carbon dioxide tension; PaO2, arterial oxygen tension; PiMax, maximal inspiratory mouth pressure (measured from functional residual capacity); RR, back-up respiratory rate; SNIP, sniff nasal inspiratory pressure (measured from functional residual capacity); TS90, time spent with transcutaneous pulsed oxygen saturation less than 90%; VC, vital capacity; Vt, tidal volume.