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 (AASM_2007Rec) and the 2012 AASM recommended hypopnea criteria (AASM_2012Rec). 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 AASM_2012Rec increased the incidence of OSA compared to AASM_2007Rec (84% vs 49% respectively). AASM_2012Rec increased the number of patients with supine predominant OSA (spOSA) and supine independent OSA (siOSA) but did not change the proportion (spOSA: 61% AASM_2012Rec vs 61% AASM_2007Rec, siOSA: 32% AASM_2012Rec vs 36% AASM_2007Rec). OSA patients diagnosed by AASM_{2007Rec criteria} had similar outcome measures to those diagnosed by the AASM_2012Rec criteria. The AASM_2012Rec 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 AASM_2007Rec, AASM_2012Rec 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 AASM_2012Rec. Furthermore, the use of different minimum recording times in each sleeping position can alter the proportion of spOSA.