The AASM 2012 recommended hypopnea criteria increase the incidence of obstructive sleep apnea but not the proportion of positional obstructive sleep apnea

Objective/Background This study compared the effects of using the 2007 and 2012 American Academy of Sleep Medicine (AASM) recommended hypopnea criteria on the proportion of positional obstructive sleep apnea (pOSA). The effect of modifying the minimum recording time in each sleeping position on the proportion of pOSA was also investigated. Patients/Methods 207 of 303 consecutive patients (91 of 207 were female) participated in polysomnography (PSG) for the suspicion of OSA met the inclusion criteria for this retrospective investigation. PSGs were scored for both the 2007 AASM recommended hypopnea criteria (AASM2007Rec) and the 2012 AASM recommended hypopnea criteria (AASM2012Rec). For each hypopnea criteria OSA patients were grouped as positional [either supine predominant OSA (spOSA) or supine independent OSA (siOSA)] or non-positional. Outcome measures such as SF-36, FOSQ, PVT, and DASS-21 were compared between groups. Results The AASM2012Rec increased the incidence of OSA compared to AASM2007Rec (84% vs 49% respectively). AASM2012Rec increased the number of patients with supine predominant OSA (spOSA) and supine independent OSA (siOSA) but did not change the proportion (spOSA: 61% AASM2012Rec vs 61% AASM2007Rec, siOSA: 32% AASM2012Rec vs 36% AASM2007Rec). OSA patients diagnosed by AASM2007Rec criteria had similar outcome measures to those diagnosed by the AASM2012Rec criteria. The AASM2012Rec increased the proportion of female OSA patients with spOSA and siOSA. A minimum recording time of 60 minutes in each position decreased the proportion of spOSA, but not siOSA patients when compared to a minimum time of 15 minutes. Conclusions This study demonstrates that, compared to AASM2007Rec, AASM2012Rec almost doubles the incidence of OSA but does not alter the proportion of OSA patients with pOSA. The proportion of female OSA patients with pOSA however, increases as a result of AASM2012Rec. Furthermore, the use of different minimum recording times in each sleeping position can alter the proportion of spOSA