Figure 2. Schematic showing the outcome of unattended home monitoring and automatic titrating continuous positive airway pressure (auto-CPAP) machine titration in the 63 subjects. Unsatisfactory diagnosis indicates subjects whose home diagnostic study results were unsatisfactory to establish a diagnosis of obstructive sleep apnea (OSA); PSMGY, polysomnography; OSA-NEG, sufficient diagnostic study results showed fewer than 10 apneas and/or hypopneas per hour of recording time; UARS, upper airway resistance syndrome; OSA, CPAP untitrated, subjects with OSA who did not complete sufficient auto-CPAP titration studies to establish an effective CPAP treatment pressure; and OSA, CPAP titrated, subjects completing diagnostic and auto-CPAP titration studies sufficient to establish a diagnosis of OSA and effective treatment pressure.