The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments section of a
UK news-site report
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given the
placebo, then if 50% of those developing Covid had been given the
placebo the Vaccine would be 0% effective. Someone other than the PR
dept should do the maths and say what the findings actually mean."
Is there some standard way of defining the effectiveness of a medical >treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
On Mon, 9 Nov 2020 16:08:35 +0000 (UTC), "David Jones" <dajhawkxx@nowherel.com> wrote:
The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments section
of a UK news-site report
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given the placebo, then if 50% of those developing Covid had been given the
placebo the Vaccine would be 0% effective. Someone other than the PR
dept should do the maths and say what the findings actually mean."
Is there some standard way of defining the effectiveness of a
medical treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
I assume that they were using the natural-language version of
effectiveness and failed to spell out the details. How many cases
were avoided or prevented?
Taking an "expected number of cases" as equal to Control, the
fraction of cases that were prevented comes to 8 of 9 -- 89%,
which rounds to 90%.
Is there another meaning?
Rich Ulrich wrote:
On Mon, 9 Nov 2020 16:08:35 +0000 (UTC), "David Jones"
<dajhawkxx@nowherel.com> wrote:
The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments section
of a UK news-site report
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given the
placebo, then if 50% of those developing Covid had been given the
placebo the Vaccine would be 0% effective. Someone other than the PR
dept should do the maths and say what the findings actually mean."
Is there some standard way of defining the effectiveness of a
medical treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
I assume that they were using the natural-language version of
effectiveness and failed to spell out the details. How many cases
were avoided or prevented?
Taking an "expected number of cases" as equal to Control, the
fraction of cases that were prevented comes to 8 of 9 -- 89%,
which rounds to 90%.
Is there another meaning?
I think the problem was the apparent direct transposition of the
percentage of observed cases having the placebo into the
"effectiveness", which is more noticably wrong for a lower
effectiveness.
The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments section of a
UK news-site report
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given the
placebo, then if 50% of those developing Covid had been given the
placebo the Vaccine would be 0% effective. Someone other than the PR
dept should do the maths and say what the findings actually mean."
Is there some standard way of defining the effectiveness of a medical treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
On Mon, 9 Nov 2020 18:58:45 +0000 (UTC), "David Jones" <dajhawk18xx@@nowhere.com> wrote:
Rich Ulrich wrote:
section >> > of a UK news-site reportOn Mon, 9 Nov 2020 16:08:35 +0000 (UTC), "David Jones"
<dajhawkxx@nowherel.com> wrote:
The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments
the >> > placebo, then if 50% of those developing Covid had been
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given
given the >> > placebo the Vaccine would be 0% effective. Someone
other than the PR >> > dept should do the maths and say what the
findings actually mean." >> >
Is there some standard way of defining the effectiveness of a
medical treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
I assume that they were using the natural-language version of
effectiveness and failed to spell out the details. How many cases
were avoided or prevented?
Taking an "expected number of cases" as equal to Control, the
fraction of cases that were prevented comes to 8 of 9 -- 89%,
which rounds to 90%.
Is there another meaning?
I think the problem was the apparent direct transposition of the
percentage of observed cases having the placebo into the
"effectiveness", which is more noticably wrong for a lower
effectiveness.
Right.
That question was from readers' comments, from some news report.
I don't recall if confusion was likely in the news report that I read.
The recent announcement about the vaccine for Covid-19 led to the
following question being included in the readers' comments section of a
UK news-site report
"Someone needs to look at this 90% effective claim. Its based on
finding that 90% of those that developed Covid had been given the
placebo ... but, assuming 50% of the overall subjects were given the
placebo, then if 50% of those developing Covid had been given the
placebo the Vaccine would be 0% effective. Someone other than the PR
dept should do the maths and say what the findings actually mean."
Is there some standard way of defining the effectiveness of a medical >treatment?
Note 43,500 in the total sample, 94 of whom developed Covid.
Sysop: | Keyop |
---|---|
Location: | Huddersfield, West Yorkshire, UK |
Users: | 113 |
Nodes: | 8 (1 / 7) |
Uptime: | 70:49:04 |
Calls: | 2,499 |
Files: | 8,667 |
Messages: | 1,913,105 |