Table A8: Summary of Study Design Characteristics*.
| Author | Study Design: Comparison |
Study Population | Intervention | Main Results (Original Study) | Comments |
|---|---|---|---|---|---|
| MRC (10) | MC RCT: LTOT vs. no LTOT | 87 patients with CB/E, CS FEV1 < 1.2 L, PaO2 40–60 mm Hg ≥ 1 episode of heart failure + ankle edema FU: up to 5 years |
LTOT (n = 42) vs. no LTOT (n = 45) FR 2 L/minute ≥ 15 hours/day including sleeping hours |
Mean age ~58 years, mean PaO2 ~50 mm Hg, FEV1 ~0.65 L LTOT 19/42 (45.2%) vs. CT 30/45 (66.7%), P = ?, Men (n = 66) > 500 days, risk of death: LTOT 12% vs. CT 29% (P = 0.04) Women (n = 21), LTOT 5.7% vs. CT 36.5% (P < 0.05) |
Severe hypoxemia, not blinded, differences in O2 source, usage check not standardized (adherence), hours? 1 DO (O2) |
| Gorecka et al (24) | MC RCT: LTOT vs. no LTOT | 135 patients with COPD FEV1/VC < 70%, PaO2 56–65 mm Hg FU ≥ 3 years or death, NS |
LTOT + UC (n = 68) vs. no LTOT + UC (n = 67) FR adjusted to > 65 mm Hg at rest ≥ 17 hours/day |
Mean age ~60 years, mean PaO2 60.4 mm Hg, mean O2 use 13.5 hours/day, FEV1 29.8%, 0 DO LTOT 38/68 (55.9%) vs. CT 32/67 (47.8%), no difference in survival (P = 0.982) |
Moderate hypoxemia, not blinded, UC included drug therapies, concentrator, adherence check, crossover? |
| Haidl et al (25) | RCT: LTOT vs. no LTOT | 28 patients with COPD + PaCO2 > 45 mm Hg at rest or exercise test, CS FEV1/VC < 70%, PaO2 > 55 mm Hg FU 3 years |
LTOT (n = 14) vs. no LTOT (n = 14) FR 2 L/minute, 15 hours/day |
Mean age ~64 years, mean PaO2 ~66 mm Hg, mean O2 use 10.4 hours/day, FEV1 ~40%, ↑ endurance time at 1 year (P = 0.04), ↓ dyspnea score at 1 year (P = 0.03), no difference in deaths after 3 years LTOT 4/14 (28.6%) vs. CT 3/14 (21.4%), P = ? | Mild hypoxemia, not blinded, concentrator, adherence check by O2 meter, 5 CTs given LTOT |
*
Abbreviations: CB/E, chronic bronchitis and emphysema; CO2, continuous oxygen therapy; COPD, chronic obstructive pulmonary disease; CS, current smokers; CT, control group; DO, dropouts; FEV1, forced expiratory volume in 1 second; FR, flow rate; FS, former smokers; FU, follow-up; L, litres; LTOT, long-term oxygen therapy; MC, multicentre; mm Hg, millimetres of mercury; MRC, Medical Research Council; NS, not significant; O2, oxygen; PaO2, arterial pressure of oxygen; RCT, randomized controlled trial; UC, usual care.