On 3/4/20 10:41 am, jw...@internode.on.net wrote:
Here's a Fact Check article that also explores how the data is
presented and compared.League tables are always misleading or at least
can easily be misinterpreted.
https://www.abc.net.au/news/2020-04-03/fact-file-are-we-turning-coronavirus-corner-flatten-the-curv/12113410
Thanks Jan. But unfortunately the article's very muddy on deaths and
death-rates (in the section that starts 40% of the way down the page).
The graph's use of colour, and the inclusion of a legend that has an
unclear relationship with the lines, makes it almost unreadable.
And this buys into one of the most silly aspects of the entire
pseudo-statistical mess:
>There is a second type of death rate. This is sometimes referred to as
the "case fatality rate".
>This tells us the number of people who are dying as a proportion of
confirmed cases.
Let's leave aside the issue of uncertain and probably variable
test-reliability (as measured by false-positive and false-negative
proportions).
Countries have adopted very different approaches to testing, and have
changed their approach over time and space, sometimes frequently.
In most cases, the sample of the population that is being tested at any
given time is intentionally not random, but targeted.
But the basis of the targeting (the sampling frame, and the manner in
which the sample is selected from the sampling frame) is highly
variable, and the execution if it is challenging and highly error-prone.
One result is that within-country counts aren't comparable over even
short periods, let alone the whole 4-8 weeks to date.
A second result is that inter-country comparisons are completely
meaningless, because the confounding variables dominate the data.
The article's right to say that "the case fatality rate is not the same
as an actual mortality rate", and "countries with limited levels of
testing might appear to have higher mortality rates — particularly if
that limited testing is being restricted to those patients with more
severe symptoms".
But it fails to say what matters, which is that "the case fatality rate
is pseudo-data, shouldn't be reported, should certainly not be compared
between countries, and is useless as a basis for any kind of
decision-making".
What's needed is clarity about causes-of-death, and about what that
tells us can be done for those in danger.
Availability of breathing support? Probably above all, availability of
quality medical and nursing staff in appropriate hospital facilities.
But maybe also a severe hosing-down of the alarmism projected by
politicians, some health policy people, and the media.
----- Original Message -----
From: "Roger Clarke"
To:"link"
Cc:
Sent:Fri, 3 Apr 2020 10:01:35 +1100
Subject:[LINK] OT: The Quality of Reporting on "COVID-19-Linked"
Deaths
Ruminations on a Friday morning ...
The sports results and tables have been replaced by coronavirus (CV)
infection-counts and death-counts. And the media declares raw
numbers,
without providing any context to them.
This morning's ABC News says that yesterday's 'CV{-linked}'
death-toll was:
Italy 760
UK 559
Spain 800
To get some perspective, that needs moderation by two key variables:
the
countries' poulations and their normal death-rates.
Death-rates are quoted as number per thousand of population p.a.
So Normal Deaths per Day = (Population/1000 * Death-Rate p.a.) / 365
I haven't been able to quickly locate indicators of the degree of
variability of deaths per day around the averages shown above, but
there
could be wide variability. In particular, winter in some countries is
likely to have higher rates than less-cold times of year.
It's not possible with current information to relate CV-caused deaths
to
normal death-rates. As a proxy measure, I've shown below the ratio of
deaths yesterday compared with average daily deaths, as a percentage:
Country Population Death-Rate Deaths per Day CV Deaths Y'day %age
Spain 46m 91 1146 800 69
Italy 60m 10.4 1709 760 44
UK 67m 9.4 1725 559 32
A number of potentially important factors muddy the water:
1. Generally, reports fail to distinguish:
a. deaths where CV appears to be the only significant factor
b. deaths where CV was a significant factor, although not the only
one
c. deaths where CV may have been a factor (e.g. diagnosed with the
virus, but nature of death not consistent with CV-caused deaths)
d. deaths where CV was present but unlikely to have been a factor
The term 'excess deaths' or 'excess mortality' indicates a+b. In
German, the word is 'Ueberstirblichkeit', as per:
https://swprs.files.wordpress.com/2020/04/mortalitc3a4t-schweiz.png
This suggests that Switzerland is experiencing a 'normal'
late-winter-flu peak in deaths among over-65s.
It may be that there is a great deal of over-reporting due to the
inclusion of c. and d. in the numbers appearing in the media. Quoting
https://swprs.org/a-swiss-doctor-on-covid-19/, "[It may be that] all
test-positive deaths are assumed to be additional deaths".
2. It may be that a 'fear-of-the-virus' anxiety factor has
exacerbated
death rates, and even resulted in deaths of individuals who are not
infected. For example, populations in countries that are less prone
to
hysteria, such as Germanic northern Europe, evidence very low rates
in
comparison with warm-blooded, Mediterranean countries.
3. A variety of reports suggest a very large proportion of deaths has
been, throughout, among those over 70 (90%), and a large proportion
had
prior conditions that were life-threatening or could readily become
life-threatening (80%).
But, apart from a number of specific instances (Wuhan, Iran?, the
upper-mid Po Valley, parts of Spain, UK, US), it appears that even
deaths among the over-70s may be within the normal statistical range.
4. It appears that in both Italy and Spain, many hospitals and
aged-care facilities lost a large proportion of their staff, in many
cases early in the epidemic. That's because staff from Eastern
European
countries were terrified by panic-ridden reporting and fled home, and
large numbers of local staff tested positive and were isolated at
home.
This may have resulted in many saveable patients going untreated and
becoming casualties of the epidemic.
--
Roger Clarke mailto:roger.cla...@xamax.com.au
T: +61 2 6288 6916 http://www.xamax.com.au http://www.rogerclarke.com
Xamax Consultancy Pty Ltd 78 Sidaway St, Chapman ACT 2611 AUSTRALIA
Visiting Professor in the Faculty of Law University of N.S.W.
Visiting Professor in Computer Science Australian National University
_______________________________________________
Link mailing list
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http://mailman.anu.edu.au/mailman/listinfo/link
_______________________________________________
Link mailing list
Link@mailman.anu.edu.au
http://mailman.anu.edu.au/mailman/listinfo/link
--
Roger Clarke mailto:roger.cla...@xamax.com.au
T: +61 2 6288 6916 http://www.xamax.com.au http://www.rogerclarke.com
Xamax Consultancy Pty Ltd 78 Sidaway St, Chapman ACT 2611 AUSTRALIA
Visiting Professor in the Faculty of Law University of N.S.W.
Visiting Professor in Computer Science Australian National University
_______________________________________________
Link mailing list
Link@mailman.anu.edu.au
http://mailman.anu.edu.au/mailman/listinfo/link
