Long-Term Oxygen Therapy Reduces Exacerbations and Hospitalisation in Chronic Lung Diseases: DISCOVERY Study

"COPD patients experienced a decline in total and hospitalized exacerbations, along with a reduction in all-cause hospitalizations. Similar benefits were observed in ILD and PH patients, while all groups showed an increase in outpatient visits following LTOT initiation," the researchers reported in the BMJ Journal Thorax.

While long-term oxygen therapy is recognized for improving survival in patients with chronic severe resting hypoxaemia, its effect on hospitalization remains uncertain. To address this, Yet Hong Khor, Respiratory Research@Alfred, School of Translational Medicine, Monash University, Clayton, Victoria, Australia, and colleagues investigated the impact of LTOT initiation on acute exacerbations and hospital burden in patients with chronic obstructive pulmonary disease, interstitial lung disease, and pulmonary hypertension.

For this purpose, the researchers conducted a longitudinal analysis of consecutive patients from the population-based Swedish DISCOVERY cohort who initiated long-term oxygen therapy between 2000 and 2018, with a follow-up period of at least three months. They compared the annualised rates of total and hospitalized acute exacerbations, all-cause hospitalizations, and all-cause outpatient visits in the year before and after LTOT initiation across each disease cohort. Additionally, in COPD patients, outcomes were assessed based on hypercapnic status.

The key findings of the study were as follows:

• COPD patients (n=10,134) experienced a significant decline in total and hospitalized acute exacerbations and all-cause hospitalizations after LTOT initiation.
• Patients with ILD (n=2,507) and PH (n=850) showed an increase in all-cause hospitalizations post-LTOT.
• All-cause outpatient visits increased across all disease cohorts following LTOT initiation.
• Similar trends were observed in hypercapnic and non-hypercapnic COPD patients.
• Sensitivity analysis of patients with 12 months of follow-up confirmed reduced acute exacerbations and all-cause hospitalizations in the ILD and PH groups.

The study highlighted the significant benefits of long-term oxygen therapy in reducing total and hospitalized acute exacerbations as well as all-cause hospitalizations in patients with chronic obstructive pulmonary disease, interstitial lung disease, and pulmonary hypertension over a 12-month follow-up period.

The researchers observed that patients initiating LTOT experienced fewer severe disease exacerbations leading to a reduced need for hospitalisation. However, they also noted a rise in all-cause outpatient visits across all disease groups, suggesting that while LTOT reduces severe exacerbations, it may necessitate closer outpatient monitoring and follow-ups.

"These findings provide valuable insights into the long-term clinical impact of LTOT and emphasize the importance of optimizing patient care strategies post-initiation," they concluded.

Reference:

Khor YH, Palm A, Wong AW, et al. Effects of long-term oxygen therapy on acute exacerbation and hospital burden: the national DISCOVERY study. Thorax Published Online First: 20 March 2025. doi: 10.1136/thorax-2023-221063