A recent study by Lindenauer, et al concluded that over time the difference in risk for hospital readmission and death was indistinguishable between patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) who received invasive ventilation vs patients who received non-invasive ventilation.1 However, a review of that study published in the American Journal of Respiratory and Critical Care Medicine suggests otherwise.2
The authors of the review noted that other large database studies of hospitalized patients demonstrated improved outcomes when treated with noninvasive ventilation compared with invasive ventilation. One study found an odds ratio of 0.54 (95% CI, 0.48-0.61) for mortality using noninvasive ventilation compared with invasive ventilation; however, no differences in hospital readmission were found between the two types of ventilation in that analysis. Likewise, comparable differences for subsequent outcomes have also been reported based on severity of disease, as measured by acidosis level, as well as the type of ventilatory support received during hospitalization.
Nonetheless, patients who receive noninvasive ventilation are more likely to have less severe disease, affecting their immediate and subsequent outcomes favorably. The review authors pointed out that this is demonstrated in the Lindenauer study data but not highlighted in the published manuscript. Lindenauer and colleagues do show a difference in 1-year mortality between the noninvasive and invasive groups (41.8% vs 45.7%), and death rates were lower at all time points (30, 60, 90, 180, and 365 days) in the noninvasive group.
The review authors argued that Lindenauer, et al failed to prove their point, and it is not known whether the difference in mortality can be attributed solely to disease severity, or if other factors such as hospital characteristics can explain these differences.
- Lindenauer PK, Dharmarajan K, Qin L, Lin Z, Gersohn AS, Krumholz HM. Risk trajectories of readmission and death in the first year following hospitalization for COPD [published online December 5, 2017]. Am J Respir Crit Care Med. doi:10.1164/rccm.201709-1852OC
- Soo Hoo GW, Esquinas AM. Risk trajectories of readmission and death in the first year following hospitalization for COPD: don’t short change non-invasive ventilation [published online March 22, 2018]. Am J Respir Crit Care Med. doi:10.1164/rccm.201802-0262LE