Background: Estimating the prevalence of severe or critical illness and case fatality of COVID-24 19 outbreak in December, 2019 remains a challenge due to biases associated with surveillance, 25 data synthesis and reporting. We aimed to address this limitation in a systematic review and 26 meta-analysis and to examine the clinical, biochemical and radiological risk factors in a meta-27 regression.
28Methods: PRISMA guidelines were followed. PubMed, Scopus and Web of Science were 29 searched using pre-specified keywords on March 07, 2020. Peer-reviewed empirical studies 30 examining rates of severe illness, critical illness and case fatality among COVID-19 patients 31 were examined. Numerators and denominators to compute the prevalence rates and risk factors 32 were extracted. Random-effects meta-analyses were performed. Results were corrected for 33 publication bias. Meta-regression analyses examined the moderator effects of potential risk 34 factors.
35Results: The meta-analysis included 29 studies representing 2,090 individuals. Pooled rates of 36 severe illness, critical illness and case fatality among COVID-19 patients were 15%, 5% and 37 0.8% respectively. Adjusting for potential underreporting and publication bias, increased these 38 estimates to 26%, 16% and 7.4% respectively. Increasing age and elevated LDH consistently 39 predicted severe / critical disease and case fatality. Hypertension; fever and dyspnea at 40 presentation; and elevated CRP predicted increased severity. 41 Conclusions: Risk factors that emerged in our analyses predicting severity and case fatality 42 should inform clinicians to define endophenotypes possessing a greater risk. Estimated case 43 All rights reserved. No reuse allowed without permission.was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. : medRxiv preprint 3 fatality rate of 7.4% after correcting for publication bias underscores the importance of strict 44 adherence to preventive measures, case detection, surveillance and reporting. 45 46 A novel corona virus, first identified in Wuhan, China in late 2019, resulted in a 64 pandemic by the first quarter of 2020, contributed by the prolonged survival of the virus in the 65 environment and extended length of pre-or post-symptomatic and potential asymptomatic 66shedding. 1-4 While the virus is known to cause only a mild illness in a majority, severe illness 67 characterized by respiratory distress requiring hospital admission is not uncommon. 5 68 Furthermore, the virus has the potential to precipitate a life-threatening critical illness, 69 characterized by respiratory failure, circulatory shock, sepsis or other organ failure, requiring 70 intensive care. 6, 7