Sudden death in individuals with obstructive sleep apnoea: protocol for a systematic review and meta-analysis

Obstructive sleep apnoea (OSA) is a form of sleep-disordered breathing, characterised by blockage of the airway, snoring, gasping for air during sleep, daytime sleepiness and fatigue. OSA is associated with increased risk of cardiovascular and cerebrovascular morbidity and mortality, and sudden cardiac death (SCD). The magnitude of this risk varies in the literature and therefore we aim to systematically assess this risk. This study protocol proposes a meta-analysis and systematic review aimed to estimate the magnitude of the association between OSA, 'sudden death' and cardiovascular death.

We will conduct a systematic review and meta-analysis of studies published from the inception of each database, which report the risk of 'sudden death' or cardiovascular death (including SCD) in individuals diagnosed with OSA versus persons without OSA. The primary outcome of interest in this study will be the relative risk of 'sudden death' in patients diagnosed with OSA in comparison to those without an OSA diagnosis. We will search the following electronic research databases: PubMed (MEDLINE), Cochrane, OVID (Healthstar), OVID (Medline), Scopus and Joana Briggs Institute EBP Database. This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines. The checklist for this document is included in the supplemental material. Two reviewers will screen articles for inclusion criteria, extracting appropriate data and evaluating the quality of the included studies. The methodological quality of studies will be appraised using an appropriate tool. Funnel plots and the Egger's test will be employed to evaluate potential publication bias. We will fit random-effects model with inverse-variance methods for the pooling effect estimates. We will conduct a meta-regression analysis, using numerous variables of interest including age, gender, race, body mass index, hypertension and diabetes, to explore sources of study heterogeneity.

CRD42020164941.

No ethics clearance was required for this protocol, for no primary data are being collected on research subjects. Only secondary analysis of pre-existing data in scientific databases will be evaluated. The findings of this meta-analysis will be published in a peer-reviewed journal and presented at scientific conferences. These results may assist professionals in the prevention and management of OSA and SCD.