Author Topic: estimating the cfr  (Read 220 times)

epsilon

  • Newbie
  • *
  • Posts: 27
  • welcome to ncovinfo , here we discuss the pandemic threat from the new 2019 Coronavirus
    • View Profile
Re: estimating the cfr
« on: February 07, 2020, 07:50:02 am »
Building upon the idea to only use the cases outside china (as a the most unbiased sample we have at this time),

[ Guests cannot view attachments ]


I thought about writing a little simulation program for calculating the probabilities (confidential intervals) of CFR given the known number of deaths among them (n=2 so far)  and the distribution of time-to-death which has been described as Weibull-like distribution in the literature so far:

[ Guests cannot view attachments ]

Luckily I found that this work has already been done by a Swiss research group who put their code and figures on github:

https://github.com/calthaus/ncov-cfr

They even regularly update their estimates based on new fatal cases outside china.

The most recent estimate is CFR = 2% (rightmost bar in the diagram)
Confidence: 5% probability that CFR is below 0.1% or above 8.8%

[ Guests cannot view attachments ]

https://github.com/calthaus/ncov-cfr/blob/master/figures/ncov_cfr.png

(Ironically: 2% is about the same number as given by the very naive and biased approach of the mass media to simply divide currently reported deaths by total cases)

Remaining biases are:
- Not counting for very mild/asymptomatic cases which would lead to CFR over-estimation.
- avg. time to death could be higher (for SARS it was over 3 weeks) which would lead to CFR under-estimation

Still, this is the first CFR estimate that I am reasonably confident in to be not too far off at least on the high side of the confidence interval. (regarding the low side I still hope that CFR will be lower in the end due to increasingly more very mild/asymptomatic infections)











 
« Last Edit: February 07, 2020, 08:31:45 am by epsilon »