Basic Reproduction Rate and Case Fatality Rate of COVID-19: Application of Meta-analysis

BackgroundThe outbreak of novel coronavirus disease of 2019 (COVID-19) has a wider geographical spread than other previous viruses such as Ebola and H1N1. The onset of disease and its transmission and severity has become a global concern. The policymakers have a serious concern for containing the spread and minimising the risk of death. AimThis study aims to provide the estimates of basic reproduction rate (R0) and case fatality rate (CFR) which applies to a generalised population. MethodsA systematic review was carried out to retrieve the published estimates of reproduction rate and case fatality rate in peer-reviewed articles from PubMed MEDLINE database with defined inclusion and exclusion criteria in the period 15 December 2019 to 3 May 2020. The systematic review led to the selection of 24 articles for R0 and 17 articles for CFR. These studies used data from China and its provinces, other Asian countries such as Japan, Korea, the Philippines, and countries from other parts of the world such as Nigeria, Iran, Italy, Europe as a whole, France, Latin America, Turkey, the United Kingdom (UK), and the United States of America (USA). These selected articles gave an output of 30 counts of R0 and 29 counts of CFR which were used in a meta-analysis. A meta-analysis, with the inverse variance method, fixed- and random-effects model and the Forest plot, was performed to estimate the mean effect size or mean value of basic reproduction rate and case fatality rate. The Funnel plot is used to comprehend the publication bias. ResultsWe estimated the robust estimate of R0 at 3.11 (2.49-3.71) persons and the robust estimate of CFR at 2.56 (2.06-3.05) per cent after accounting for heterogeneity among studies, using the random-effects model. The regional subgroup analysis in a meta-analysis was significant for R0 but was not significant for CFR. The R0 values varied from 1.90 (1.06-2.74) persons to 3.83 (2.44-5.22) persons across the regions. The Funnel plot confirms that the selected studies are significant at one per cent level of significance. ConclusionWe found that one person is likely to infect two to three persons in the absence of any control measures, and around three per cent of the population are at the risk of death within one-and-a-half months from the onset of disease COVID-19 in a generalised population. The emergence of SARS-CoV-2 varies across regions, but the risk of death remains the same. ContributionThe estimates of R0 and CFR are independent of data from a particular region or time or a homogeneous population. These estimates are applicable to a generalised population. Therefore, the estimates of R0 and CFR are unequivocally applicable to developing country like India and its states or districts, in ambivalence. The assessments of R0 and CFR values across the developed nations make all of us aware of consequences of COVID-19, and hence these estimates are of crucial importance for government authorities for the practical implementation of strategies and control measures to contain the disease. O_TEXTBOXResearch Highlights O_LIThe robust estimate of Basic Reproduction Rate (R0) of COVID-19 based on a meta-analysis performed on the pieces of evidence available across countries is 3.11 (2.49-3.71) persons for a generalised population in the absence of any control measures C_LIO_LIThe robust estimate of Case Fatality Rate (CFR) based on a meta-analysis performed on the pieces of evidence available across countries equals to 2.56 (2.06-3.05) per cent for a generalised population in approximately one-and-a-half months from the onset of the disease COVID-19. C_LIO_LIA significant regional variation is evident for the Basic Reproduction Rate (R0) but not for the Case Fatality Rate (CFR) C_LIO_LIThe peer-reviewed articles with a small sample size do not suffer from publication bias in a meta-analysis of COVID-19. C_LI C_TEXTBOX O_TEXTBOXAdded Value of this StudyOut study combine available evidence of the parameter values, such as reproduction rate and case fatality rate, of the generalised epidemiological models for coronavirus disease of 2019 (COVID-19). In this way, we have reduced the dependency on data from a particular region or time or a homogeneous population. By applying meta-analysis, we estimated the robust estimate of reproduction rate and case fatality rate, which is applicable across heterogeneous populations. We proclaim that the reproduction rate of COVID-19 varies across subgroups of populations and regions and periods, but the case fatality rate remained the same. These estimates of reproduction rate and case fatality rate are worthwhile for developing countries like India and at a lower level of geography, in ambivalence. C_TEXTBOX