Prevalence of long-term effects in individuals diagnosed with COVID-19: a living systematic review

ObjectivePost COVID-19 condition refers to persisting or recurring symptoms weeks after acute COVID-19 illness which can significantly impact quality of life and health systems. It is important to understand the manifestation and magnitude of this condition. The objective of this living systematic review is to summarize the prevalence of symptoms and sequelae reported by people [≥]4 weeks after COVID-19 diagnosis. DesignSystematic review, meta-analysis and narrative synthesis. Data sourcesEmbase, Medline, PsychInfo, Cochrane Central and select grey literature up to April 14, 2021. MethodsWe adapted a previous search strategy used by the U.K. National Institute for Health and Care Excellence and updated it to search for new literature. Two reviewers screened references independently; one extracted data and assessed risk of bias and certainty of the evidence while another verified them. Prevalence data from laboratory-confirmed populations were meta-analyzed using a random effects model and synthesized separately in the short-term (4-12 weeks) and long-term (>12 weeks) periods after diagnosis. Data from clinically-diagnosed populations were synthesized narratively. ResultsOf the 4444 unique citations, 84 observational studies met our inclusion criteria. Over 100 post COVID-19 symptoms and sequelae were reported. Sixty-one percent (95% CI: 44-76%, low certainty) and 53% (95% CI: 41-65%, low certainty) of laboratory-confirmed individuals reported persistence or presence of one or more symptoms in the short- and long-term periods, respectively. The most prevalent symptoms in both periods included: fatigue, general pain or discomfort, shortness of breath, cognitive impairment and mental health symptoms. ConclusionsA substantial proportion of individuals reported a variety of symptoms [≥]4 weeks after COVID-19 diagnosis. Due to gaps in the research base, and the low certainty of the evidence currently available, further research is needed to determine the true burden of post COVID-19 condition in the general population and in specific subgroups. PROSPERO registration numberCRD42021231476.