Trying to make sense of the figures

Brendan Burgess

Brendan Burgess

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More detail about the number of tests.

www.rte.ie

Covid 19: 25 more deaths and 480 new cases

The Department of Health has confirmed 25 more deaths from Covid-19 in Ireland, bringing the total number of deaths from the disease to 288.
www.rte.ie www.rte.ie

The total number of Covid-19 cases now confirmed in Ireland is 8,089.

Initially the department had announced a figure of 7,054 but revised that this evening to include test results from Germany.

The department said to date there has been 14,000 samples returned from German labs, of which 1,035 were positive.

When those figures are included it brings the total number of confirmed cases in Ireland to 8,089.
 
OK. These were the figures before the correction.

4427
 
They actually tell you very little about the progress of the disease.

On April 10, there were 480 + 1,035 cases confirmed.

But these swabs were probably taken 7 to 10 days ago. And the people got the infection up to 21 days before that.

The actual numbers of new cases in the population today could be a lot higher or a lot lower. We just don't know.

We would suspect that with the physical distancing, the new infections are very low. But we just don't know.

Brendan
 
So the Department of Health should say something like

1,515 people
Who became infected with Covid between 1 March and 15 March
Were tested between 10 March and the 25 March
And we got the results back today to tell us that they were positive.

Brendan
 
They have to get on top of the testing ASAP. It’s quickly becoming an issue and could lead to people losing the faith! It’s also vital for the exit plan from these restrictions

It looks like they have it solved now with the new suppliers on board that can do 900k tests. Hopefully over the next week this gets sorted and we have a better picture of where we are at.

At least the death rate appears to be slowing as the amount of deaths seems to be level for the last week or so.
 
The test numbers tell you nothing because it’s so arbitrary.
The body count is the only true reflection, and the deaths per million.
The USA has been doing a better job than Ireland in terms of DPM!
 
Drakon said:
The body count is the only true reflection, and the deaths per million.
Click to expand...

Hi Drakon

But to plan ahead, we need to know whether the virus is still spreading or not. The death count tells us only about the infection rate 20 days ago.

But I suppose if the death rate starts to fall, it will tell us that the infection rate started falling three weeks ago,

Brendan
 
I'm probably getting into semantics here Brendan but I think your summary has two errors so to make full sense of the figures I'm going to point them out.

1. The results of the tests processed in Germany have been coming in gradually for at least a few days and they have been announced daily. The department just totalled them yesterday and added them to the total of positive tests processed in Ireland.

2. The 480 figure yesterday were more recent tests processed in Ireland.

Brendan Burgess said:
1,515 people
Who became infected with Covid between 1 March and 15 March
Were tested between 10 March and the 25 March
And we got the results back today to tell us that they were positive.
Click to expand...

So my understanding is:

"1,035 people
Who became infected with Covid between 1 March and 15 March
Were tested between 10 March and the 25 March
And we got the results back over the past few days to tell us that they were positive."

At this stage I think the number of confirmed cases is relatively unimportant, due to all the issues with the testing. Some of these issues were beyond the control of the authorities but I think they should have done more to keep the public informed on the amount of testing being done. The way the figures have been presented over the past couple of days has also left a lot to be desired.
 
There are four people in my house.
My wife tested positive.
I was sick for two weeks.
My son was sick for about five days.
My daughter was sick for one night.


The test figures would suggest one case.
Common sense suggests three cases, and possibly four.
 
This is from the update released by the Department yesterday. When questioned repeatedly about it Dr Holohan could see no problem with the presentation of the figures:

"480 new cases of COVID-19 in Ireland have been confirmed. There are now 7054 confirmed cases of COVID-19 in Ireland.

Including test results which have been sent to Germany for testing (which may include tests from older cases) the total figure of those who have been diagnosed with COVID-19 in Ireland now stands at 8,089."

(Italics added)
 
llgon said:
At this stage I think the number of confirmed cases is relatively unimportant, due to all the issues with the testing.
Click to expand...

Hi ligon

That is the point I was making.

It is an unreliable figure based on inadequate testing carried out 10 days ago.

It tells us nothing about how the virus is spreading today.

Brendan
 
Drakon said:
There are four people in my house.
My wife tested positive.
I was sick for two weeks.
My son was sick for about five days.
My daughter was sick for one night.
Click to expand...

Hi Drakon

How is your wife now?

Were you all tested and three of you came out negative?

I had been in contact with a confirmed case and was "under the weather". If I had Coronavirus, by the time I would have been tested , I would probably have recovered so I might have come up negative. If I had got the results 10 days after the test, it wouldn't have told me anything about my health on that day.

I presume that the test tells you only "You are positive". Or does it tell you "You are very heavily infected and will be a few weeks before you are no longer infectious" ?

Brendan
 
She’s fine, she’s back to work. Had one bad night where she’d difficultly breathing and considered calling the doctor, but our cases were mild.
I had been scheduled to have a test but after a week they changed the criteria and I never heard anything again.
My wife was the only one tested.
AFAIK she was told she was positive, that I was it, no further description.
She was meant to be re-tested five days after all symptoms cleared, and then a double check test again the day after that. But neither of those tests happened.
I assume I was positive as my symptoms were very similar to hers. Likewise with my son though his bout was shorter. My daughter, well, who knows. She was vomiting one night but may have been otherwise asymptotic.

I look forward at anti-body testing.
 
Drakon said:
She’s fine, she’s back to work.
Click to expand...

Drakon said:
She was meant to be re-tested five days after all symptoms cleared, and then a double check test again the day after that. But neither of those tests happened.
Click to expand...

That is very interesting. I presume that her doctor cleared her to go back to work?

Is it that simple. 5 days without symptoms means that you are no longer infectious?

Brendan
 
Brendan Burgess said:
Is it that simple. 5 days without symptoms means that you are no longer infectious
Click to expand...

When you can stop self-isolating
Only stop self-isolation when both of these apply to you:

  • you have had no fever for 5 days
  • it has been 14 days since you first developed symptoms
www2.hse.ie

If you have COVID-19

If you have COVID-19, you need to stay at home for 5 days and avoid contact with other people, especially people at higher risk from COVID-19.
www2.hse.ie www2.hse.ie
 
I am now convinced that the only reliable and meaningful figure is the number of deaths. The rest is noise as the new cases figures show.

4430


The best estimate we can get for the true number of new infections is by working back from the number of deaths.

If we assume that the death rate is 2% , it means that we had 700 new cases about 19 days ago. (I might not have the assumptions correct, but you get the methodology)

We should see the death rate falling if the restrictions introduced 16 days ago are having an impact.

Brendan
 
Iirc from other studies cfr is estimated to be more like .35% when counting asymptomatic and mild experiences. I.e. lots of folks that will not have turned up in our testing.
 
Even deaths can suffer from attribution issues and/or lack of testing. But I agree it is the most reliable number for trend.

although as I mentioned elsewhere it is a lagging rather than leading indicator.
 
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