AmbOx trial: does ambulatory oxygen improve quality of life in patients with fibrotic interstitial lung disease?

We evaluated whether supplemental oxygen, used during routine daily activities, improves quality of life in patients with fibrotic interstitial lung disease (ILD). Study design: multicenter, randomized, cross-over controlled clinical trial (NCT02286063), evaluating quality of life during two weeks on ambulatory oxygen compared to two weeks off. Inclusion criteria: SaO2 ≥ 94% at rest, dropping to ≤88% on a 6MWT, stable symptoms during a 2 week run-in period. Primary outcome: health status assessed by KBILD questionnaire. Analysis: general linear model with the difference in health status as the dependent variable and treatment sequence as fixed effect. Patient views were explored through topic-guided interviews in a subgroup. Results: 41 patients randomised to ambulatory oxygen, 43 to no oxygen, crossing to the alternative arm after two weeks. Mean age 64.5±1.1 yrs, 58 males, 53 ever smokers, FVC 73.3±19.1%, DLCO 38.7±12.8%. 43 patients had possible/definite IPF. 76 patients completed the trial. Serious adverse events, equally distributed across arms, were not related to ambulatory oxygen usage. Ambulatory oxygen, compared to no oxygen, was associated with improvements in total KBILD score (difference: 3.7; p<0.0001), breathlessness and activity domain (difference: 8.7; p<0.0001), chest symptoms domain (difference: 7.6; p=0.009), but not psychological domain. Most patients reported symptom reduction and increased activity, but concerns were reported by some e.g. storage, dependency. Conclusions: the novel observation that ambulatory oxygen is associated with improved quality of life is expected to influence future ILD specific guidelines on ambulatory oxygen use.