1. Kaplan-Meier survival curves for outcomes among COPD patients, overlap patients on CPAP, and overlap patients not on CPAP. CPAP treatment was not randomly assigned, a source of potential bias, although markers of disease severity were similar, on average, in the treated and untreated groups.
Kaplan-Meier survival curves for outcomes among COPD patients, overlap patients on CPAP, and overlap patients not on CPAP. CPAP treatment was not randomly assigned, a source of potential bias, although markers of disease severity were similar, on average, in the treated and untreated groups. OSA = obstructive sleep apnea. (From Reference 78, with permission.)‏
Robert L Owens Respir Care 2013;58:32-47
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