P022 Unattended home sleep studies have a high recording failure rate in a preoperative anaesthetic clinic cohort when done as a routine screening procedure for Obstructive Sleep Apnoea (OSA)

INTRODUCTION: Preoperative screening for OSA is strongly advised but attended laboratory sleep studies have limited availability. Portable unattended sleep monitors, such as ApneaLink, may provide a practical solution for large scale preoperative OSA screening. However, these unattended monitors may be prone to data recording failure. METHODS: We performed a prospective, uncontrolled, before-after study from March 2017 to December 2018 where patients from a pre-operative anaesthetic clinic were screened for OSA with an ApneaLink home sleep study (AHSS). 24 initial patients were provided with version 1 (v.1) recording instructions, while the next 24 patients received version 2 (v.2) which included colour, more detail and larger pictures compared to v.1. Recording failure was defined as an absence of recorded ApneaLink data. We analysed predictors of recording failure including instruction version and patient factors using logistic regression. RESULTS: Thirty-three of 48 (69%) patients successfully completed an AHSS. Failure rate was 31%. Median duration of recorded data was 480 minutes. The successful recording group was more likely to have used v.2 instructions than the failure group (61% vs. 27%; p=0.029). The odds ratio for successful recording using v.2 was 4.2 (95% CI: 1.1–16.2). Age, gender, country of birth, and number of days prior to surgery were not associated with recording failure. DISCUSSION: There was a high failure rate of AHSS for OSA screening from a preoperative anaesthetic clinic. Clear written instructions with greater use of colours and pictures may improve the recording success rate in this cohort.