To want to tear my hair out when people talk about the ‘R number’ increasing - IT DOESN’T MEAN WHAT YOU THINK IT MEANS!

[GinFling]

I am SO sick of everyone having a hot take on this virus - from friends and colleagues, and especially the media. Article after article about how the R value is increasing, nearly over 1, etc etc, and how this means we are heading for a second wave/disaster/the sky falling in. No, it is more complex and nuanced than that, and in fact it’s harder and harder to have a low R as the virus gets less prevalent. It is also hugely skewed by local outbreaks - such as in care homes and hospitals.

These two articles are quite helpful in understanding it:
www.bbc.co.uk/news/amp/health-52944037
unherd.com/2020/05/what-the-headline-covid-figures-dont-tell-you/

I wish everyone would just STOP using R to pretend to know what they’re talking about. We’re not all statisticians or virologists, for good reason.

[PMSpam]

Is anyone else thinking (while GinFling shrieks hysterically at everyone that they DON'T UNDERSTAAAAAAAND) "well, no matter what her hot flush is, I still don't want to be sitting next to the 1 in 1700 in the Palladium who's coughing their guts up...it'd be a bit churlish to shush them during Joseph if they were a few breaths off dying..."

[ginghamstarfish]

Don't know what a hot take is, but surely you know that many people talk about things they don't really know about. They're idiots.

[GimmeAy]

It's simple. If the R value goes above 1, it means you're infecting more than one person. So that person will be infecting more than just one person to replace themselves etc. etc. etc. So the number of those infected will be increasing rather than stabilising/staying 1 for 1 (one gets it, one recovers). You don't need to be a scientist to understand. If I'm infecting more than one person, and they're infecting more than one person, then the amount of people with it in the population will increase.

[GinFling]

@PMSpam I’ll ignore most of your hilarious post... But, given that for the vast majority of people, if they were that one person it would be no worse than nasty flu. So on balance, going to the shop, reopening schools, etc, is a risk worth taking. For sure mass gatherings are a way off, but the rest? Fine.

[Teateaandmoretea]

If I'm infecting more than one person, and they're infecting more than one person, then the amount of people with it in the population will increase.

In the community that is true.

However, a hospital can have an outbreak where lots of people get infected but it is contained to a group of people.

So there could potentially be a town with zero cases over a week. One person is admitted to hospital from a neighbouring area who has covid. They pass it to 5 people while in hospital. The R is 5 but the important thing is to contain the outbreak rather than worry about the statistic that 5 people caught it. If there are 1000 cases in every town it is a far more useful measure.

[HesterShaw1]

Gimme it's not that simple at all. That theory assumes all places have identical environments (inside vs outside, for example), and that everyone has an equal susceptibility to infection, which they don't. Some people will never get it. Some people are particularly vulnerable to getting it. And that's before we even look at their likelihood of developing the illness severely or whether they are one of the majority who remain largely unaffected.

Therefore R is just one way of measuring infection rates in an area.

[mocktail]

@GimmeAy I think that's the bit everyone understands. But it's a lot more complex than that.

1 person spreading the virus to 1 person gives an R rate of 1, potentially for an entire town or region. Whereas 10,000 people spreading the virus to 9,500 gives an R rate of 9.5. But it's clear which one is worse.

So R rate is only one part of the picture and is potentially very misleading once the number of cases becomes very low, and can be massively skewed by one relatively small outbreak in a care home or hospital.

[mocktail]

Sorry reading the first line back it sounds really patronising which it wasn't meant to I just meant I agree that R rate itself isn't complicated.

[GimmeAy]

They pass it to 5 people while in hospital. The R is 5 but the important thing is to contain the outbreak rather than worry about the statistic that 5 people caught it. If there are 1000 cases in every town it is a far more useful measure


The R value as measured overall is on a UK basis. Pockets will have higher and lower R values. But if the overall average R is above 1 in the UK population as a whole, that is not good.

[Beatingthisthing]

@mocktail. I think you meant 0.95 🙂

[HesterShaw1]

The R value as measured overall is on a UK basis. Pockets will have higher and lower R values. But if the overall average R is above 1 in the UK population as a whole, that is not good.

No it's not, but it also depends hugely on numbers of infections.

If the infection is now, what, 1 in 1700? the R rate is way less significant than it was back in March when it was much higher.

[Noextremes2017]

The OP is absolutely right.

R is used in a misleading way as a means of scaring the population so they comply with every stupid little over-complicated concession being made as we come out of lockdown.

Some on here are saying the media are to blame. Quite probably - and the role of the BBC throughout this has been shameful - just parroting everything the Government says without question.

But the Government and their SAGE advisors must take the bulk of the blame. As has been said on other posts - other countries are not obsessing over the R number. A few nights ago Vallance was giving some ridiculous over complicated explanation of R and it's significance like it was a precisely calculated number. It is based on small sample sizes and 'computer modelling' and at best it is a pure guess.

[GimmeAy]

Dear oh dear.

[GimmeAy]

It's easy to calculate. If today 1 person has it, and tomorrow, two people have it, it's pretty likely that the R value is 2.
If in the population today, 2000 people have it and tomorrow 6000 people have it, then the R value is 3.
If today 100 people have it and tomorrow, 100 people have it (same people who have it), the R value is 1. 1 for 1

[GimmeAy]

How you can't understand that the R value needs to be under 1 I can't understand.

Can you understand interest rates?

Think of it like R of 1 = 0% interest.
If you deposit £1 today, in a year you'll have £1
If you have an R value of 4 however if the interest rate is 400%
In a year you'll have £4 saved from your £1.

[jasjas1973]

@Noextremes2017

Merkel placed great store on the Rate going from 1.3 to 1.5 as she demonstrated to the public what that meant to the pressures on the German healthcare system.

Who has handled CV better - Germany or the UK ?
We still have, according to ONS, 14k to 64k weekly CV infections, its falling, which is great news but its still very high, we need it down in the 100s as we ease lockdown and in 4 months, go into the Autumn.

So, whilst we all have a valid POV, i will look at what public health officials say, rather than randoms on MNs many of whom seem only interested in defending Johnson.

[nellodee]

I am not so certain I do agree with you. How large does a single outbreak need to be to affect the R for an entire county? How low does the prevalence need to be?

Obviously, there are thresholds at which R becomes less meaningful, however, I am not absolutely certain we are at those thresholds yet.

[Snowdown24]

Take a deep breath mrs know it all!!

[nellodee]

Weighed against this is the political benefit of saying R is not meaningful anymore, just as it is exceeding 1.

[GinFling]

@GimmeAy a lot of other posters have explained it much better than you Very much not a case of not understanding the R value needs to below one- but that it is much more nuanced than that. Maybe RTFT?

[Noextremes2017]

@jasjas1973

To answer your question - apparently the Germans have handled it much better. But maybe their success was based on acting decisively at the start when our SAGE experts were changing their advice and opinion from one meeting to the next (possibly to appease their political masters - who knows?) That's not a point of view - just read the published minutes of SAGE meetings.
It hit us AFTER continental Europe so our decisions should have been better and more informed - based on more available data.

That Merkel can explain something more clearly than Johnson & Co is not surprising at all.

[GinFling]

@GimmeAy also rereading your post, it’s actually wrong. You said -
‘It's easy to calculate. If today 1 person has it, and tomorrow, two people have it, it's pretty likely that the R value is 2.’
Nope - the R will be 1, as the original person has affected one other person. So two people in total have it.

[Teateaandmoretea]

@GimmeAy

You need to stop sighing and dramatically ‘oh dear’ ing and at least try to understand the bigger picture outside the bloody R. It can and will go up and down, politicians are going talking nonsense crap about ‘local r’ and the northwest at one point ‘in places’ had an R of 1.01. Utter bollocks on so many levels.

[0v9c99f9g9d939d9f9g9h8h]

OP, I've never thought the R number meant what you have described as 'the belief'. I think you're assuming people are not as clever as you and being rather snotty about it.

[0v9c99f9g9d939d9f9g9h8h]

But, given that for the vast majority of people, if they were that one person it would be no worse than nasty flu. So on balance, going to the shop, reopening schools, etc, is a risk worth taking.

Ah. So that's what this is about. 'Understand' the science and come to my conclusions already...