Association of frailty and cognitive function disorders in old patients with COVID-19: a protocol of systematic review and meta-analysis

Introduction COVID-19 infections have become an urgent worldwide public health concern. Although it is primarily a respiratory disease, up to two-thirds of hospitalised COVID-19 patients exhibit nervous system damage and an increased risk of frailty. In this study,we aim to investigate the relationship between frailty and cognitive function disorders in patients with COVID-19 with a systematic review and meta-analysis approach. Methods and analysis This meta-analysis has been registered by the International Prospective Register of Systematic Reviews. We will search for relevant studies from PubMed, Embase, Chinese Biological Medical Database, China National Knowledge Infrastructure, Wanfang Database, the Cochrane Central Register of Controlled Trials databases, from their inception to 5 July 2021. We will also search reference lists of selected articles for additional studies. Our search strategy will have no language restrictions. We will employ a ?xed or random-effects model to calculate OR and 95% CIs for pooled data, and assess heterogeneity using Cochrane's Q and I-2 tests. The primary outcome will be the rate of cognitive disorders related to frailty in old patients with COVID-19. Ethics and dissemination Ethical approval is not essential since data will be extracted from previously published studies. The results of this meta-analysis will be published in a peer-reviewed journal. PROSPERO registration number CRD42021257148.