Table 1 Baseline characteristics of patients with advanced cancer according to oxygen use
|  | Oxygen use (n = 35) | No oxygen use (n = 102) | Total (n = 137) |
|---|---|---|---|
Age, median (IQR), years | 74 (69–80) | 78 (69–83) | 77 (69–82) |
Sex, male, no. (%) | 18 (51) | 67 (66) | 85 (62) |
Systolic blood pressure, mean (SD), mmHg | 117.0 (21.9) | 104.1 (22.8) | 107.3 (23.1) |
 Unknown, no. (%) | 2 (5.7) | 1 (1.0) | 3 (2.2) |
Heart rate, mean (SD), beats/min | 102.7 (17.9) | 94.1 (17.8) | 96.3 (18.2) |
 Unknown, no. (%) | 1 (2.9) | 3 (2.9) | 4 (2.9) |
Respiratory rate, median (IQR), breaths/min | 23 (18–33) | 20 (16–27) | 20 (16–30) |
 Unknown, no. (%) | 13 (37) | 45 (44) | 58 (42) |
Oxygen saturation, median (IQR), % | 85 (82–87) | 86 (83–88) | 85 (83–88) |
 Unknown, no. (%) | 1 (2.9) | 0 (0) | 1 (0.7) |
Decreased level of consciousness, no. (%) | 14 (40) | 57 (56) | 71 (52) |
 Unknown | 0 (0) | 1 (1.0) | 1 (0.7) |
Dyspnea, no. (%) | 25 (71) | 19 (19) | 44 (32) |
 Unknown | 0 (0) | 0 (0) | 0 (0) |
Edema, no. (%) | 13 (37) | 48 (47) | 61 (45) |
 Unknown | 0 (0) | 6 (5.9) | 6 (4.4) |
Oral intake, no. (%) | |||
 Normal | 8 (23) | 10 (9.8) | 43 (31) |
 Reduced | 19 (54) | 55 (54) | 74 (54) |
 Impossible | 7 (20) | 36 (35) | 18 (13) |
 Unknown | 1 (2.9) | 1 (1.0) | 2 (1.5) |
ECOG performance status, no. (%) | |||
 1 | 0 (0) | 1 (1.0) | 1 (0.7) |
 2 | 9 (26) | 8 (7.8) | 17 (12) |
 3 | 17 (49) | 46 (45) | 63 (46) |
 4 | 9 (26) | 44 (43) | 53 (39) |
 Unknown | 0 (0) | 3 (2.9) | 3 (2.2) |
Cardiopulmonary comorbidity, no. (%) | 11 (31) | 4 (3.9) | 15 (11) |
 Heart failure | 5 (14) | 3 (2.9) | 8 (5.8) |
 Chronic obstructive pulmonary disease | 4 (11) | 1 (1.0) | 5 (3.6) |
 Interstitial lung disease or radiation pneumonitis | 4 (11) | 1 (1.0) | 5 (3.6) |
 Severe asthma | 1 (2.9) | 0 (0) | 1 (0.7) |
Primary tumor sites, no. (%) | |||
 Gastrointestinal | 11 (31) | 53 (52) | 64 (47) |
 Lung | 14 (40) | 23 (23) | 37 (27) |
 Urologic | 3 (8.6) | 14 (14) | 17 (12) |
 Hematologic | 4 (11) | 3 (2.9) | 7 (5.1) |
 Head and neck | 1 (2.9) | 4 (3.9) | 5 (3.6) |
 Unknown | 2 (5.7) | 2 (2.0) | 4 (2.9) |
 Gynecologic | 1 (2.9) | 2 (2.0) | 3 (2.2) |
 Breast | 0 (0) | 2 (2.0) | 2 (1.5) |
 Central nervous system | 1 (2.9) | 1 (1.0) | 2 (1.5) |
 Skin (melanoma) | 0 (0) | 1 (1.0) | 1 (0.7) |