Covid-19 IFR studies

Alvez_48

Alvez_48

Well-known member
Apologies for poor formatting (copy paste innit). An exhaustive list of IFR studies performed..


1) Covid-19 infection fatality rates (IFR) based on antibody studies
Population-based antibody seroprevalence studies.

CountryPublishedPopulationIFR (%)SourceGlobalMay 19Most countries
Three hotspots<0.20
<0.40StudyGermanyMay 4Heinsberg Cluster<0.36¹StudyIranMay 1Guilan province<0.12StudyUSAApril 30Santa Clara County0.17StudyDenmarkApril 28Blood donors (<70y)0.08StudyUSAApril 24Miami-Dade County0.18²ReportUSAApril 21Los Angeles County<0.20Study

1) The adjusted IFR is 0.278% (see page 9 of study); 2) Based on 300 deaths.

2) Covid-19 infection fatality rates based on controlled PCR studies
Controlled PCR studies in population subgroups.

CountryDatePopulationIFR (%)SourceUSAMay 10MLB employees0.00ReportFranceMay 10Aircraft carrier0.00ReportUSAMay 10Aircraft carrier0.09ReportUSAMay 1Tennessee prison0.00ReportItaly²April 28Health workers0.30StudyUSAApril 17Boston homeless0.00ReportUSAApril 17Boston blood donors0.00ReportShipApril 17Diamond Princess0.13¹StudyGreeceApril 16Repatriations0.00StudyUSAApril 13NYC pregnant women0.00Study

1) Age-adjusted IFR based on US population.

2) Deaths in Italian health care workers by age group (ISS, April 28, 2020)

3) Covid-19 infection fatality rates based on models
Covid-19 IFR based on epidemiological models or predictions. These values are often somewhat higher than the actual values based on serological antibody studies (see above).

CountryPublishedPopulationIFR (%)SourceFranceMay 13France0.70StudySwitzerlandMay 11Switzerland0.40StudyUKMay 7UK0.08¹StudyFranceMay 7France0.80²StudyGlobalMay 5Global0.17StudyIndiaMay 3India0.41StudyItaly
USAApril 20Lombardia
New York City>0.84
>0.50StudyChinaMarch 30Mainland China0.66StudyChinaMarch 13Wuhan city0.12StudyChinaMarch 9Mainland China0.50
 
Interesting to see the walk-in antibody testing site on Guernsey yesterday as part of the feature on how they'd eradicated the disease (in the short term!)
 
Not sure what that has to do with the post but bravo!

Just to add little section on hospitalisation rate:-

7) Hospitalization rate
Initial estimates based on Chinese data assumed a very high 20% hospitalization rate, which led to the strategy of ‘flattening the curve’ to avoid overburdening hospitals. However, population-based antibody studies (see above) have since shown that actual hospitalization rates are close to 1%, which is within the range of hospitalization rates for influenza (1 to 2%).

The US CDC found that Covid-19 hospitalization rates for people aged 65 and over are “within ranges of influenza hospitalization rates”, with rates slightly higher for people aged 18 to 64 and “much lower” (compared to influenza) for people under 18.

In local hotspots like New York City, the overall hospitalization rate based on antibody studies is about 2.5% (19.9% or 1.7 million people with antibodies and 43,000 hospitalizations by May 2).

The much lower than expected hospitalization rate may explain why most Covid-19 ‘field hospitals’ even in hard-hit countries like the US, the UK and China remained largely empty.
 
bear66 said:
Apologies for reading "Population-based antibody seroprevalence studies."

I'll read between the lines next time.
Click to expand...

You managed to miss the title and the first line of the post which is the only bit I wrote and then also managed to miss all of the content apart from the very first numbered point.
I'm almost offended! 🤣
 
The IFR studies were antibody studies. Sorry if that's offensive.

To build on my post, hopefully we'll soon see mass antibody testing in the UK as all the studies you've referenced have had to have massive statistical adjustments to provide a broad range of confidence levels.
 
bear66 said:
The IFR studies were antibody studies. Sorry if that's offensive.

To build on my post, hopefully we'll soon see mass antibody testing in the UK as all the studies you've referenced have had to have massive statistical adjustments to provide a broad range of confidence levels.
Click to expand...

What are you talking about?! IFR studies are study's that look at Infection Fatality Rate the clue is in the acronym, please read the post.

'2) Covid-19 infection fatality rates based on controlled PCR studies' (not anti body studies)

3) Covid-19 infection fatality rates based on models'
 
Thanks for that 'exhaustive' list. Just for the sake of balance, here's the abstract from the recently published systemic review of 13 different IFR studies that you appear to have missed:

Introduction: An important unknown during the COVID-19 pandemic has been the infection-fatality rate (IFR). This differs from the case-fatality rate (CFR) as an estimate of the number of deaths as a proportion of the total number of cases, including those who are mild and asymptomatic. While the CFR is extremely valuable for experts, IFR is increasingly being called for by policy-makers and the lay public as an estimate of the overall mortality from COVID-19.

Methods: Pubmed and Medrxiv were searched using a set of terms and Boolean operators on 25/04/2020. Articles were screened for inclusion by both authors. Meta-analysis was performed in Stata 15.1 using the metan command, based on IFR and confidence intervals extracted from each study. Google/Google Scholar was used to assess the grey literature relating to government reports.

Results: After exclusions, there were 13 estimates of IFR included in the final meta-analysis, from a wide range of countries, published between February and April 2020. The meta-analysis demonstrated a point-estimate of IFR of 0.75% (0.49-1.01%) with significant heterogeneity (p<0.001).

Conclusion: Based on a systematic review and meta-analysis of published evidence on COVID-19 until the end of April, 2020, the IFR of the disease across populations is 0.75% (0.49-1.01%). However, due to very high heterogeneity in the meta-analysis, it is difficult to know if this represents the "true" point estimate. It is likely that different places will experience different IFRs. More research looking at age-stratified IFR is urgently needed to inform policy-making on this front.
 
It is a pretty exhaustive list though isn't it...

As a doom monger you completely ignore anything that doesn't fit your narrative I note your comments conveniently only cover data up to over a month ago. The IFR will only fall even further as time goes on.

And yes laughing I was told off but I can't understand why bear was failing to grasp my simple post. 😋
 
The main reason that IFR is so hard/impossible to work out is because no-one yet knows how large the mild/asymptomatic portion of the population is, even with serological testing (given that people known to have been infected have not shown antibodies in tests). And if the innate response has dealt with the virus in many cases (including children and young people for instance) it is nigh on impossible to arrive at an accurate IFR.

Eventually, in a year or so, deaths as a percentage of population might give us an alternative benchmark (though even that will be flawed). Sweden's current deaths % of population is a shade under 0.04.
 
Alvez_48 said:
It is a pretty exhaustive list though isn't it...

As a doom monger you completely ignore anything that doesn't fit your narrative I note your comments conveniently only cover data up to over a month ago. The IFR will only fall even further as time goes on.

And yes laughing I was told off but I can't understand why bear was failing to grasp my simple post. 😋
Click to expand...

I'm not a doom monger at all. I am however a realist, who bases his judgement on the weight of evidence.

The basic difference between you and me is that you believe the virus is highly contagious and has, therefore, already infected a far higher proportion of the population (>50%), thus making the IFR smaller. My view is that the evidence suggests that the proportion of the population already infected is relatively small (<10%) and, therefore, the IFR is bigger.

The majority of the emerging evidence is pointing in the direction of a smaller incidence and therefore a higher IFR. However, there are some studies which are contradictory. What really matters, of course, is the IFR in this country, which we should start to get a better idea about as the ONS survey results begin to be published.

In the meantime, we have to work out how to get out of lockdown in a way which allows the economy to start up again, whilst managing the risk of a second wave. Using your assumptions, you would expect that risk was very small, so further measures would be unneccesary. Under my assumptions, you would expect the risk to be higher, so would want something like an effective test, track and isolate system in place.

That's basically all we're arguing about.
 
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The infection to fatality rate % can be key to estimating how many people have had the virus. As some know I have tried to work backwards from number of deaths to estimate infection numbers. The rate has to be across all society to make it useful. I would expect countries with overweight and older population to be have a higher fatality rate say UK opposed to Vietnam with a young population that is generally slimmer. So I would expect significant differences. Mind you Vietnam does not even have a rate, because no one has officially died there yet of the Virus.

I do believe in general in some form of herd immunity (we can't forecast a successful vaccine yet and if it happens its likely sometime in 2021 for most of us). With this in mind what interests me is the level of natural immunity to serious illness from CV19 in the population. . It is obviously significant with this virus, because very few younger adults and children suffer at all. Although we need to know if these younger people are carriers. The same with older people many of whom must have been exposed (to a very contagious virus for certain types) but have avoided any signs of the virus.

Based on the Diamond Princess statistics it would fair to say at least 50% of the population would never catch the Virus if exposed and show positive.

My guess is about 8 to 10% in the UK have been infected in a way to test positive at some stage, but there could another group who are invisible carriers and I haven't a clue on their number. That is invisible to tests even.
 
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Redwurzel said:
The infection to fatality rate % can be key to estimating how many people have had the virus. As some know I have tried to work backwards from number of deaths to estimate infection numbers. The rate has to be across all society to make it useful. I would expect countries with overweight and older population to be have a higher fatality rate say UK opposed to Vietnam with a young population that is generally slimmer. So I would expect significant differences. Mind you Vietnam does not even have a rate, because no one has officially died there yet of the Virus.

I do believe in general in some form of herd immunity (we can't forecast a successful vaccine yet and if it happens its likely sometime in 2021 for most of us). With this in mind what interests me is the level of natural immunity to serious illness from CV19 in the population. . It is obviously significant with this virus, because very few younger adults and children suffer at all. Although we need to know if these younger people are carriers. The same with older people many of whom must have been exposed (to a very contagious virus for certain types) but have avoided any signs of the virus.

Based on the Diamond Princess statistics it would fair to say at least 50% of the population would never catch the Virus if exposed and show positive.

My guess is about 8 to 10% in the UK have been infected in a way to test positive at some stage, but there could another group who are invisible carriers and I haven't a clue on their number. That is invisible to tests even.
Click to expand...

Billy doesn't believe in the people with natural immunity and t cell immunity ..
It's good news for the rest of us though because brings that herd immunity through quicker.
I think it will be all but gone in a couple of weeks but I'd guess there will be a seasonal hit come October which could be similar in effect to this one.
The key in my opinion is to open the feck up now to give as much shielding in November

P.s.Billy I'm just kidding I know your not really a doom monger but you do tend to be overly negative about any good looking news.
 
It makes logical sense... If the only immunity is from anti bodies and the numbers given are correct (7%) then you would see huge spikes in infection rates this past 8-12 days.

More tests being done per day - (interestingly papers including the 'hallowed' guardian have made it very difficult to find daily tests conducted now there aren't as many confirmed cases everyday... Wonder why?!)

Same or less people positive everyday

Despite far more socialising (and trust me it's going on everywhere).
 
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