To Calculate Mortality, Many Methods are Utilized.
The Covid 19 Pandemic- 3 – Testing volume, healthcare system quality, treatment choices, government reaction, duration since the first epidemic, and demographic factors, such as age, sex, and general health, all impact these statistics, which vary by area and by time. In countries like Belgium, fatalities from suspected cases, even those without a test, are included, resulting in an increase in the number of cases.
Within a particular time frame, the death-to-case ratio is calculated by dividing the number of deaths linked to COVID-19 by the number of diagnosed cases. According to figures from Johns Hopkins University, the worldwide death-to-case ratio was 1.97 percent as of December 11th, 2021 (5,299,935 fatalities for 269,441,881 cases). Depending on the area, the number changes.
Official death tolls have been criticized for underreporting the true death toll, since comparisons of mortality rates before and after the pandemic reveal an increase in fatalities that cannot be explained only by COVID 19 Pandemic deaths.
The Economist estimated 9.5 to 18.6 million COVID-19 fatalities globally, whereas the Institute for Health Metrics and Evaluation estimated over 10.3 million.
The WHO assigned two codes for COVID-19, according to the US Centers for Disease Control and Prevention (CDC) on March 24, 2020: U07.1 for laboratory confirmation and U07.2 for clinical or epidemiological diagnosis when laboratory confirmation is equivocal or unavailable.
“Because laboratory test results are not typically reported on death certificates in the United States,” according to the CDC, “[the National Center for Health Statistics (NCHS)] is not planning to implement U07.2 for mortality statistics,” and U07.1 would be used “if the death certificate reports terms such as ‘probable COVID-19’ or ‘likely COVID-19’.” While the “underlying cause” “depends on what and where conditions are documented on the death certificate, the standards for coding and selection of the cause of death are projected to result in COVID 19 Pandemic being the underlying cause more frequently than not,” according to the CDC.
The WHO “does not discriminate” between SARS-CoV-2 and COVID-19 infection, according to the report.
The percentage of people who die from infection (IFR)
The infection fatality ratio (IFR), which is defined as the total number of fatalities related to the illness divided by the total number of infected persons, is a critical parameter in appraising a disease (including asymptomatic and undiagnosed infections).
To emphasize that this statistic is stated in percentage points, epidemiologists sometimes refer to it as the ‘infection fatality rate’ (not as a decimal). This statistic is known as the ‘infection fatality risk’ in other published investigations.
A research analysis published in Nature in November 2020 revealed a median range of 0.24 percent to 1.49 percent for population-weighted IFRs in different nations, excluding fatalities in aged care institutions.
In comparison to older individuals, children and younger adults had substantially lower IFRs (e.g., 0.002 percent at age 10 and 0.01 percent at age 25). (0.4 percent at age 55, 1.4 percent at age 65, 4.6 percent at age 75, and 15 percent at age 85). Across age groups, these rates differ by a factor of 10,000.  A fatal COVID-19 infection is two orders of magnitude more probable for middle-aged individuals than the annualized risk of a fatal vehicle collision, and significantly more hazardous than seasonal influenza.
According to this research, the majority of the disparities were due to age-related variations in the population and infection patterns particular to each age group.
The proportion of cases that die (CFR)
The case fatality ratio (CFR), which is the ratio of fatalities to diagnoses, is another statistic used to estimate mortality rate. Since the time between development of symptoms and death, and because testing is limited to symptomatic people, this statistic may be deceptive (and particularly on those manifesting more severe symptoms). “At this early stage of the pandemic, most estimates of fatality rates have been based on cases found via surveillance and estimated using basic methodologies, giving rise to highly varying CFR estimates by country – from less than 0.1 percent to over 25 percent,” WHO, August 4, 2020.
Pradeep Chopra, MD
The Long Covid Treatment Center
102 Smithfield ave.
Pawtucket, RI 02860