Sleep in Chronic Obstructive Pulmonary Disease: Evidence Gaps and Challenges

Figure 1

(a) Kaplan-Meier survival curves for survival among COPD patients, overlap syndrome patients without CPAP treatment, and overlap syndrome patients on CPAP treatment. This study included only severe OSA patients (AHI > 30), and CPAP was not randomly assigned (from [3], permission granted); (b) Kaplan-Meier survival curves for survival among patients with COPD and OSA overlap syndrome, stratified by CPAP use per night (from [22], permission granted).

(a)

(b)