Ambulatory oxygen for COPD

Patient or population: adults with COPD who had exertional dyspnoea but did not fulfil the criteria for long‐term oxygen treatment
Settings: home and hospital
Intervention: ambulatory oxygen

Control: placebo/medical air

Exercise capacity (5‐ or 6‐minute walking distance on cylinder air)
Follow‐up: 2 to 12 weeks

Not estimable

331
(4 studies)

Not applicable

Meta‐analysis not possible; see effects of interventions for more information

Mortality
Follow‐up: mean 12 weeks

RR 4.17
(0.48 to 36.3)

179
(2 studies)

⊕⊕⊕⊝¹

Moderate

Although deaths occurred only in the intervention arm of the study (n = 3), they were not believed to be a direct result of the intervention

Quality of life (dyspnoea)
Measured on the CRQ, the output is a number from 0 to 7, where higher on the scale is better. MID is 0.5.

Follow‐up: 2 to 12 weeks

MD 0.28 (0.10 to 0.45)

341
(4 studies)

⊕⊕⊕⊝²

Moderate

Other CRQ domains were also reported, including fatigue MD 0.14 (95% CI 0.04 to 0.31; P value 0.009), emotional function MD 0.10 (95% CI ‐0.05 to 0.25; P value 0.20) and mastery MD 0.13 (95% CI ‐0.06 to 0.33; P value 0.17)

Dyspnoea
Follow‐up: 6 to 12 weeks

Not estimable

198
(3 studies)

Not applicable

Meta‐analysis not possible

Dyspnoea was measured in 3 studies using the Borg scale, and 1 study reported dyspnoea during exercise. One study observed improvement in dyspnoea after walking for 6 minutes with cylinder air or oxygen. Another study showed a clinically relevant reduction in dyspnoea scores for the oxygen group post 5MWD compared with placebo

Adverse events
Follow‐up: mean 12 weeks

OR 0.77
(0.21 to 2.81)

83
(2 studies)

⊕⊕⊝⊝
low^1,3

Only 1 of the adverse events appeared related to the intervention; this was strain due to carrying the cylinder

Hospitalisations

Not estimable

0
(0)

See comment

No studies reported data on hospitalisations

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
5MWD: 5‐Minute Walking Distance test; CI: Confidence interval; COPD: Chronic obstructive pulmonary disease; CRQ: Chronic Respiratory Disease Quesionnaire; MD: Mean difference; MID: Minimally important difference; OR: Odds ratio; RR: Risk ratio.

GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.