The Pandemic Severity Index (PSI) was developed by the Department of Health and Human Services in 2007 in the USA, and improved by their Centre for Disease Control and Prevention. Interestingly, the concept of the PSI scale was designed to resemble the Saffir-Simpson Hurricane Scale classification scheme.
CDC Pandemic Severity Index Chart
| Category | Case Fatality Rate | Examples |
| 1 | Less than 0.1% | seasonal flu and swine flu |
| 2 | 0.1% – 0.5% | Asian Flu and Hong Kong flu |
| 3 | 0.5% – 1.0% | |
| 4 | 1.0% – 2.0% | |
| 5 | 2.0% or higher | 1918 – 1920 influenza pandemic (Spanish flu) |
So which Category does Covid-19 fit on the PSI scale ? As I mentioned yesterday, Views range from Category 1 (Brazil’s President Bolsonaro’s view that the virus is “a little flu” or the “sniffles”), Category 2 (S Korea, Iceland, Germany & Denmark referenced yesterday) to Categories 3- 4 ( WHO – based on my extrapolations yesterday of a death rate range of 0.85% – 1.28% , calculated from their reported 2% – 3% overall population Covid-19 infection rate), or somewhere in between.
I do not know the answer and neither does anyone else, as far as I can tell, including the WHO, and thousands of scientific experts, medical academics and economists around the World. I am just an old man in South Wales with a laptop, an Excel spreadsheet and time on his hands. Only time will tell who is right.
Urgent update – Pandemic Severity Index Category 5 ??
The coronavirus pandemic has already caused as many as 41,000 deaths in the UK, according to a Financial Times analysis of the latest data from the Office for National Statistics.
The estimate is more than double the official figure of 17,337 released by ministers on Tuesday, which is updated daily and only counts those who have died in hospitals after testing positive for the virus. The FT extrapolation, based on figures from the ONS that were also published on Tuesday, includes deaths that occurred outside hospitals updated to reflect recent mortality trends.
Source Financial Times online – https://www.ft.com/content/67e6a4ee-3d05-43bc-ba03-e239799fa6ab
Based on yesterday’s extrapolations from the WHO statistic of a 2%-3% Covid infection rate, using the FT extrapolation of 41,000 UK deaths yields a frightening death rate of between 2.02% and 3.02%. This would raise the PSI to Category 5 , potentially above that of the Spanish flu 1918-20. Someone please tell me I am wrong !!
Yesterday’s extrapolated calculations updated :
Total number of deaths in UK (Financial Times extrapolation (21st April 2020)
Based on WHO infection rate @ 2% = 41,000/1,356,000 = 3.03% Death rate
Based on WHO infection rate @ 3% = 41,000/2,034,000 = 2.02% Death rate
