P180 Apnoea-hypopnoea-index comparing the AASM 2007 and 2012 criteria in COPD/obstructive sleep apnoea overlap syndrome. (12th November 2019)

• Record Type: Journal Article
• Authors: He, BT; Sherif, M; Higgins, S; Schwarz, E; Luo, YM; Said, A; Steier, J
• Is Part Of: Thorax. Volume 74(2019)Supplement 2
• Page Start: A187
• Page End: A188
• Publication Date: 2019-11-12
• Subjects: Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thorax-2019-BTSabstracts2019.323
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Background: In 2007 and 2012, the American Academy of Sleep Medicine (AASM) updated their scoring criteria for nocturnal respiratory events. We hypothesised that this could have led to changes in the apnoea-hypopnoea index (AHI) and thus diagnosis of COPD associated obstructive sleep apnoea (OSA) overlap syndrome. Patients and methods: In a retrospective study, polysomnographical recordings (PSG) of 11 patients with COPD/OSA overlap syndrome were independently analysed using the AASM criteria from 2007 and 2012. The primary outcome was the difference in AHI between the AASM 2012 and the AASM 2007 recommended and alternative scoring rules, secondary outcomes were the percentage of hypopnoeas and the diagnosis of overlap syndrome. Data are presented as mean (standard deviation) if normally distributed, and as median (interquartile range) for non-normally distributed data. Results: The PSG of 11 obese, elderly and predominantly male patients with mild-moderate COPD were analysed (table). The AHI using AASM 2007 (recommended) criteria was 12.9 (5.8, 16.9) h -1 vs 18.7 (11.3, 24.7) h -1 using the 2012 criteria (p<0.001); with the altered AASM 2007 criteria, the AHI was 10.7 (4, 19.1) h -1 (p<0.001). With the 2012 classification, the number of scored hypopnoeas increased by +25.7% (p<0.001) compared to the AASM 2007 (recommended) criteria, 41% of these events were associated with arousal. Although non-significant for the AASM recommended classification, 18% of our cohort would not have been diagnosed with COPD/OSA overlap syndrome using the old criteria ( p =0.238), this was true for 36% of the cohort when the AASM 2007 altered classification was used ( p =0.045). Conclusion: The AHI significantly increases when the AASM 2012 instead of 2007 criteria are used in patients with COPD/OSA overlap syndrome, in parts due to a higher number of arousal-associated hypopnoeas. These observations will impact on the definition of the COPD/OSA overlap syndrome.