The mean AHI difference between SPT and APAP treatments for mild (AHI 5 to < 15 events/h), moderate (AHI 15–30 events/h), and severe (AHI > 30 events/h) categories of severity. The error bars are the 95% confidence intervals of the means. The mean group AHI differences were not different across OSA severity (P = .4235). AHI = apneahypopnea index, APAP = auto-adjusting positive airway pressure, OSA = obstructive sleep apnea, SPT = sleep position treatment.