Table 2 Participant characteristics (N = 400)*

General characteristics

N (%)*

 Mean (SD)

64.2 (15.2)

 Min to max

18.7 to 95.1

Male gender

212 (53)

 Current

43 (10.8)

 Ex

203 (50.9)

 Never

153 (38.5)

 I

44 (11)

 II

198 (49.5)

 III

127 (31.8)

 IV

30 (7.5)

 V

1 (0.3)

 VI

0 (0)

 None:

229 (57.3)

  Hypercapnia** on ABG

16

 At least one:

171 (42.8)

  Hypercapnia** on ABG

57

 Chronic obstructive pulmonary disease

113 (28.3)

 Obesity hypoventilation syndrome

30 (7.5)

 Bronchiectasis

19 (4.8)

 Cystic fibrosis

1 (0.3)

 Neuromuscular disease

24 (6)

 Chest wall deformity

11 (2.8)

Peripheral vascular disease

11 (2.8)

Diabetes

80 (20)

Oxygen administration

25 (6.3)

 NZ European

280 (70.0)

 Māori

26 (6.5)

 Samoan

13 (3.3)

 Chinese

1 (0.3)

 Indian

4 (1.0)

 Cook Island Māori

1 (0.3)

 Tongan

3 (0.8)

 Other

28 (7.0)

 Caucasian

34 (8.5)

 Middle Eastern

6 (1.5)

 Other

5 (1.3)

 Outpatient

341 (85.3)

 Ward

40 (10)

 HDU

18 (4.5)

 ED

1 (0.3)

ABG and oximetry data

Mean (SD), min-max*

Median (IQR)

 SpO₂, %

93.5 (3.8), 72 to 100

94 (92 to 96)

 Participants with SpO₂<90% (N, (%))

49 (12.3)

 Concern with SpO₂ data accuracy recorded by investigator (N, (%))***

16 (4.0)

 SaO₂, %

94.7 (3.8), 72.1 to 100

95.7 (93.2 to 97.1)

 Participants with SaO₂<90% (N, (%))

35 (8.8)

 PaO₂, mmHg

74.8 (21.3), 37.9 to 396

73 (64.7 to 83)

 Participants with PaO₂<60 mmHg (N, (%))

61 (15.3)

 PaCO₂, mmHg

40.3 (7.2), 25.4 to 87.2

39 (35.8 to 43.4)

 Hb, g/L

136.7 (18.8), 67 to 192

137 (126.5 to 149)

 All participants (N = 358)

2.1 (1.2), 0 to 7

1.8 (1.4 to 2.3)

 Current smokers (N = 40)

3.9 (1.7), 0.9 to 6.7

4.0 (2.4 to 5.4)

 Ex smokers (N = 183)

1.9 (0.9), 0.0 to 7.0

1.7 (1.4 to 2.2)

 Never smokers (N = 135)

1.9 (0.7), 0.0 to 4.2

1.7 (1.3 to 2.3)