Background: The prevalence of obstructive sleep apnoea (OSA) in the bariatric population has been reported to be as high as 60-83%. The Epworth Sleepiness Scale (ESS) is a validated, self-administrated eight-item questionnaire that measures subjective daytime sleepiness and thus helps to identify high-risk for OSA.
Objectives: To find the prevalence of OSA in patients undergoing bariatric surgery who do not routinely undergo polysomnography (PSG) and are screened by the ESS.
Methods: All consecutive 425 patients who underwent bariatric surgery in our tercier referral centre from January 2012 to June 2017 were included in this prospective study. Patient demographics and ESS score were recorded prior to the bariatric surgery and patients were divided into low-risk (ESS < 11), high-risk (≥ 11) and "known-OSA" groups.
Results: The community-based OSA prevalence was 14% (59 patients). ESS-positive predictive value was 60%. There was no significant difference in BMI and excess body-weight, but patients with OSA were older and had a lower female ratio (75% vs 42%). The unplanned ICU admission rate was comparable amongst the low- and high-ESS group (2.2% and 2.1%, respectively); similarly, the respiratory and chest complication rate were similar. The median hospital stay for patients diagnosed with OSA was a half day longer; the high-score patients stayed significantly longer than the low-score patients (p = 0.017).
Conclusion: In our study, the OSA prevalence was low (20%). We think that the ESS does not have significant predicting value before bariatric surgery and overall the OSA is "overhyped" in the bariatric pathway.
Keywords: Bariatric surgery; Gastric bypass; Obstructive sleep apnoea; Preoperative screening; Risk prediction.