Association of frailty status with adverse clinical outcomes in patients with COVID-19: protocol for a systematic review and dose–response meta-analysis

INTRODUCTION: Frailty status has been recognised as an important prognostic factor of adverse clinical outcomes in various clinical settings. Recently, the role of frailty status in adverse clinical outcomes for COVID-19-infected patients has received increasing attention with controversial results. Hence, we will conduct a comprehensive dose–response meta-analysis to quantitatively evaluate the association between frailty status and adverse clinical outcomes in patients with COVID-19. METHODS: The researchers will systematically search PubMed, EMBase, Cochrane Library, ISI Knowledge via Web of Science and MedRxiv or BioRxiv databases (from inception until December 2020) to identify all retrospective and prospective cohort studies. All-cause mortality during hospitalisation will be set as the primary outcome. Univariable or multivariable meta-regression and subgroup analyses will be conducted for the comparison between frail versus non-frail categories. Sensitivity analyses will be used to assess the robustness of our results by removing each included study one at a time to obtain and evaluate the remaining overall estimates of all-cause mortality. To conduct a dose–response meta-analysis for the potential linear or restricted cubic spline regression relationship between frailty status and all-cause mortality, studies with three or more categories will be included. ETHICS AND DISSEMINATION: In accordance with the Institutional Review Board/Independent Ethics Committee of the First Affiliated Hospital of Baotou Medical College, ethical approval is not an essential element for the systematic review protocol. This meta-analysis will be disseminated through publication in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42020220226.