Table 2.
Comparison of survey respondents and nonrespondents based on baseline data reported to Swedevox
| Characteristic at Starting LTOT | Nonrespondents (n = 462) | Respondents (n = 151) |
|---|---|---|
| Age, mean (SD), yr | 75.0 (10.6) | 74.7 (8.6) |
| Women, n (%) | 321 (69.5%) | 89 (58.9%) |
| BMI, mean (SD), kg/m2 | 27.8 (8.34) | 28.1 (7.63) |
| Cause for starting LTOT (grouped), n (%) | ||
| Airway disease | 321 (69.9%) | 113 (75.3%) |
| Parenchymal lung disease | 41 (8.9%) | 20 (13.3%) |
| Other | 97 (21.1%) | 17 (11.3%) |
| Missing | 3 (0.65%) | 1 (0.67%) |
| Years since LTOT start, median (IQR) | 2.5 (1.2–4.7) | 2.2 (1.0–3.8) |
| Arterial blood gas values, median (IQR) | ||
| PaO2 air | 6.7kPa (6.1–7.1) 50.3mm Hg (45.8–53.3) | 6.9kPa (6.3–7.2) 51.8 mm Hg (47.3–54.0) |
| PaO2 oxygen | 8.5kPa (7.9–9.1) 63.8 mm Hg (59.3–68.3) | 8.7kPa (8.0–9.4) 65.3 mm Hg (60.0–70.5) |
| PaCO2 air | 5.8 kPa (5.0–6.6) 43.5 mm Hg (37.5–49.5) | 5.6 kPa (4.7–6.4) 42.0 mm Hg (35.3–48.0) |
| PaCO2 oxygen | 6.0 kPa (5.1–6.9) 45.0 mm Hg (38.3–51.8) | 5.9 kPa (4.9–6.6) 44.3 mm Hg (36.8–49.5) |
| Spirometry, median (IQR) | ||
| FEV1, L | 0.9 (0.6–1.5) | 1.1 (0.7–1.5) |
| FEV1, % of predicted | 41.7 (28.2–62.1) | 42.0 (31.4–55.6) |
| Oxygen prescription at treatment initiation, median (IQR) | ||
| Time, h/d | 16 (16–24) | 16 (16–20) |
| Flow rate, L/min | 1.5 (1–2) | 1.5 (1–2) |
| CAT score, mean (SD) | 20.9 (6.6) | 20.0 (7.5) |
| WHO performance status, median (IQR) | 1 (1–3) | 1 (1–2) |
Definition of abbreviations: BMI = body mass index; CAT = chronic obstructive pulmonary disease assessment test; FEV1 = forced expiratory volume in 1 second; IQR = interquartile range; LTOT = long-term oxygen therapy; PaCO2 = partial pressure of carbon dioxide in arterial blood; PaO2 = partial pressure of oxygen in arterial blood; SD = standard deviation; Swedevox = Swedish National Registry for Respiratory Failure; WHO = World Health Organization.
Characteristics of respondents and nonrespondents were compared using Student’s t test (continuous variables with normal distributions), the Mann-Whitney U test (ordinal and continuous variables with non-normal distributions), and Pearson’s chi2 test (categorical variables).