BLOG: Covid-19 results in much higher mortality than currently estimated- Dr Ishwar Gilada
Entire world has been held hostage and has come to a stand-still following lock-down of various degrees and intensities from place to place and country to country. Statistics is suddenly everyone's favourite subject. Each one is hooked onto global and nation-specific details as the Covid-19 pandemic unfolds at an ever increasing pace. I would like to deal specifically with discrepancies related to possible death rates using two different systems.
The current understanding on death rates in Covid-19 patients in different countries as mere 2% or between 1 to 4% according to different agencies is inaccurate and may lead to serious underestimates. The death rates different among different countries due to parameters like aging population, prevailing standard of healthcare, testing facilities, sudden upsurge in Covid-19 cases etc. The WHO so far indicates that the crude mortality ratio (the number of reported deaths divided by the reported cases) is between 3-4%" 1 , updating from its earlier stand of 2% 2 . The Worldometers that dynamically maintains global Covid-19 data, states CFR as 2% or 3%. However, the very basis of calculating the Covid-19 death rate is incorrect. If we do not analyze and interpret data properly, the scientific information disseminated currently through print, electronic and social media may lead to inadequate preparation to confront the Coronavirus pandemic. By and large CFR or gross death rate of Covid-19 as of now (i.e 6 th April, 2020) is 5.5%. This in itself has increased by 275% from the initial figure of 2%, (as evident below):
|Date||No of Covid-19 cases||Covid-19 deaths||CFR in Covid-19|
|1st Feb 2020||14553||304||2%|
|1st March 2020||88585||3050||3.7%|
|6th April 2020||1346004||746545|
On in depth analysis, the picture is different, with actual death rate potentially manifold from what we have been using for projections. Death being a terminal stage of a life, its exact number even in the context of Covid-19 is seen only in 'closed cases'; where the outcome is seen in the form of either recovered or dead. But, additional deaths will happen and will get recorded from the active cases as they transition through to the stage of outcome.
1) Of the recorded cases, 353099 had outcome: 79% recovered / discharged and 21% dead and is worsening each day. Of the current 'active cases', 95% have mild disease, while 5% are serious or critical. Whereas the cases with final outcome are static, the number of active cases are dynamic. In natural course of disease, some mild cases may worsen and progress to critical ones. Similarly some of the critical ones may recover and survive. Based on current knowledge and with conservative estimates, we can presume that only 5% of those with mild conditions may transition to the critical stage. Half of cumulatively counted critical ones may survive and remaining half may succumb. So this movement of cases from the first sub-group to the second may eventually take the total number of critical cases to 10% and mortality among them to 5%. This figure being numerically similar as the percentage of cases with 'serious/critical conditions', for statistical purpose, the number of currently critical ones would eventually equal the number of deaths. The mild cases can be presumed to represent 100% recoveries. Hence, as the cases start getting closed (i.e either recovery or death), the final plausible death rate may be closer to a staggering 9.1%! This comes from 122167 presumed deaths (47513 critical + 74654 deaths) in 1346004 detected cases.
2) The person who dies today of Covid-19, may have been in treatment for days to weeks. Mortality rates can be re-estimated by dividing the number of deaths on a given day by the number of patients with confirmed COVID-19 infection 14 days before. 3 It may be just 7 days if clinical facilities are compromised either due to inadequate or compromised medical care. Hence the number of total deaths as on 6th April had occurred from the Covid-19 diagnosed cases as on either 23 rd March (14 day-window) or 30th March (7 day-window) and calculated death rates as against CFR are as below:
|Reference date||Total cases||Total deaths||Death rate||calibrated deaths 6th April|
Using any criteria, the Covid-19 death rate ranges between 9 to 19.7%. With the most conservative estimatesit can be 10%; which is five times more than popularly thought of. Even rich and G7-countries like Italy(21%),
France(20%), Spain(15%) have very disturbing calculated CFR. Germany, Austria, Canada, USA, Switzerland and Scandinavia have death rates from 1.5 to 3% and with calculations it may be about 5%.
The most significant thing India has done is a relatively quicker nation-wide lock-down. That could help us stem the epidemic, reducing both morbidity and mortality related to Covid-19. Till date, India has done only 80000 Coronavirus tests, way lower than most countries globally, but the capacity is getting enhanced. In India-specific information, there is no division on number of critical or serious Covid-19 patients for India.
|Global Active Cases = 992905|
Global Closed Cases = 353099
|Mild Cases||Critical cases||Recovered||Deaths|
|Global||945392 (95%)||47513 (5%)||278445 (80%)||74654 (20%)||1346004|
At this stage we must make efforts to avert deaths among non-Covid 19 patients as well, as I fear that the care for other critical cases is already compromised and may get worse over next few months. That loss and those number of deaths will not be even part of any statistics!
1. WHO Coronavirus disease 2019 (COVID-19) Situation Report – 46 accessed on March 7, 2020
4. All numbers in tables accessed from https://www.worldometers.info/coronavirus
The author Dr. Ishwar Gilada, is Consultant in HIV and Infectious Diseases, Unison Medicare & Research Centre, President AIDS Society of India and Governing Council Member, International AIDS Society
Disclaimer: The views expressed in the above article are solely those of the author/agency in his/her private capacity and DO NOT represent the views of Medical Dialogues.