A new model that used data from China and several other nations has demonstrated that COVID-19 is deadlier than the 2009 H1N1 flu and its case-fatality ratio rises rapidly with age.

The research team determined that the overall case-fatality ratio in China was 1.38%. But, among those aged 60 and above, it was 6.4% and it rose rapidly up to 13.4% for those 80 and older.

“From extensive analysis of data from different regions of the world, our best estimates at the current time for the case fatality ratio of COVID-19 are 1.38. Although this value remains lower than estimates for other coronaviruses, including SARS and the Middle East respiratory syndrome (MERS), it is substantially higher than estimates from the 2009 H1N1 influenza pandemic," MDLinx quoted the research team led by Robert Verity, a research fellow at Imperial College in London.

The researchers analyzed 24 mainland Chinese patients, who died and 165 patients, who recovered outside of China. Their estimates suggested that the meantime from the onset of symptoms to death was 17.8 days and the meantime to hospital discharge for survivors was about 25 days.

The key findings of the study:

  • The data from over 70,000 patients suggested that the overall case fatality rate was 1.38%.
  • But, breaking it down by age group, they found that the ratio was 0.32% among people below 60 years old.
  • The estimates from China were in line with that of other nations. The overall ratio was between 1.4% to 4.5% among those over 60.
  • Rates of infected individuals likely to be hospitalized also increased with age: up to a maximum of 18.4% in older adults aged 80 and above.

They also included a parameter called exponential growth with a rate of 0.14 per day since a higher proportion of cases have been reported recently.

"The importance of this paper is that it narrows down reasonable estimates of case fatality rates," MDLinx quoted Dr. Mark Roberts, a professor, and chair of the department of health policy and management at the University of Pittsburgh.

"When you read newspaper reports you see estimates ranging from 4% to 0.5%. This is really important information for capacity planning: how many ICU beds and ventilators are you going to need. This is one of the better jobs of synthesizing data from multiple sources that I've seen," Roberts added.​

A French first aid worker from the Protection Civile Paris Seine holds an oxygen mask over the mouth and nose of a male patient suspected of being infected with COVID-19 a he lies in an ambulance
Representation. AFP / Lucas BARIOULET
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