FIGURE 2.

Study flowchart. Of the 1851 participants enrolled in the ISAACC trial, 1255 patients with obstructive sleep apnoea (OSA) were considered for the present post hoc analysis. Respiratory polygraphy (RP) data were available for a total of 793 patients, of whom 33 had irregularities in the sleep recording and 33 involved inadequate arterial oxygen saturation (S_aO2) signal quality. The final study cohort comprised 727 OSA patients. AHI: apnoea–hypopnoea index; CPAP: continuous positive airway pressure.