Risk factors affecting COVID-19 case fatality rate: A quantitative analysis of top 50 affected countries

Abstract

Background: Latest clinical data on treatment on coronavirus disease 2019 (COVID-19) indicated that older patients and those with underlying history of smoking, hypertension or diabetes mellitus might have poorer prognosis of recovery from COVID-19. We aimed to examine the relationship of various prevailing population-based risk factors in comparison with mortality rate and case fatality rate (CFR) of COVID-19.
Methods: Demography and epidemiology data were used, which have been identified as verified or postulated risk factors for mortality of adult inpatients with COVID-19. The number of confirmed cases and the number of deaths until April 16, 2020 for all affected countries were extracted from Johns Hopkins University COVID-19 websites. Datasets for indicators that are prevailing or postulated factors of COVID-19 mortality were extracted from the World Bank database. Out of 185 affected countries, the top 50 countries were selected for analysis in this study. The following seven variables were included in the analysis, based on data availability and completeness: 1) proportion of people aged 65 above, 2) proportion of male in the population, 3) smoking prevalence, and 4) number of hospital beds. Linear regression analysis was carried out to determine the relationship between CFR and the aforementioned risk factors.
Results: United States shows approximately 0.20% of confirmed cases and it has about 4.85% of CFR. Luxembourg shows the highest percentage of confirmed cases of 0.55% but a low 2.05% of CFR, showing that a high percentage of confirmed cases does not necessarily lead to high CFR. There is a significant association between CFR, people aged 65 and above (β=4.70; p = 0.035).
Conclusion: Countries with high proportion of older people above 65 years old have a significant risk of having high CFR from COVID-19. Nevertheless, gender differences and smoking prevalence failed to prove a significant relationship with COVID-19 mortality rate and CFR.