Amsterdam positional OSA classification: the AASM 2012 recommended hypopnoea criteria increases the number of positional therapy candidates.

PURPOSE: This study examined the effect of hypopnoea criteria on the prevalence of positional obstructive sleep apnoea (pOSA) identified under the Amsterdam Positional OSA Classification (APOC) system.

METHODS

Three hundred three consecutive patients undertaking polysomnography (PSG) for the suspicion of OSA were included in this retrospective investigation. PSGs were scored using both the 2007 American Academy of Sleep Medicine (AASM) recommended hypopnoea criteria (AASM2007Rec) and the 2012 AASM recommended hypopnoea criteria (AASM2012Rec). For each hypopnoea criteria, OSA patients were grouped according to the APOC categories (I, II or II) or else deemed non-APOC if they did not meet the APOC criteria. Outcome measures, such as Functional Outcomes of Sleep Questionnaire (FOSQ), MOS 36-item short-form health survey (SF-36) and psychomotor vigilance task (PVT), were also compared between the groups.

RESULTS

The AASM2012Rec increased the prevalence of OSA compared to AASM2007Rec. The AASM2012Rec trebled the number of APOC I patients compared to AASM2007Rec (297% increase) as well as increased the proportion of females in the APOC I group. AASM2012Rec did not change the number of APOC II and APOC III patients. In fact, the same patients were present in these categories irrespective of hypopnoea criteria. The proportion of non-APOC patients proportionally decreased with the AASM2012Rec criteria. There were no differences in outcome measures between the AASM2012Rec and AASM2007Rec groups.

CONCLUSIONS

This study demonstrates that, compared to AASM2007Rec, AASM2012Rec increases the prevalence of who could be successfully treated with positional therapy. The proportion of females with pOSA also increases as a consequence of AASM2012Rec.