Unintentional leaks, patient-ventilatory asynchrony, and obstructive or central events (either residual or induced by noninvasive positive pressure ventilation [NPPV]) occur in patients treated with NPPV, but the impact of ventilator settings on these disturbances has been little explored. The objective of this study was to investigate the impact of backup respiratory rate (BURR) settings on the efficacy of ventilation, sleep structure, subjective sleep quality, and respiratory events in a group of patients with obesity hypoventilation syndrome (OHS).