This series on COVID tries to analyse data objectively and aims to avoid the twin dangers of fear and complacency; prevent a large second wave - and a second national lockdown.
No 7. Flu has not killed more people than COVID over the last few months - but staying at home has.
There has been a widespread misunderstanding of the graph below which the ONS releases every Tuesday with many reports and people saying that influenza has been killing many times more people than COVID-19 over the last three months.
This is mainly because of the way deaths are recorded by the ONS (who combine the categories for influenza & pneumonia) and also the difference between ‘dying of’ a disease (an actual underlying cause of death) and ‘dying with’ a disease (did not contribute to the death).
So why is this claim wrong?
First, most deaths from pneumonia are not caused by influenza - less than 5% over the whole of last year and much less outside of flu season. (November to March)
Second, we still don’t have the data from this year for ‘dying of’ versus ‘dying with’ influenza but from previous years, ‘influenza & pneumonia’ were an actual cause of death in about 30% of cases (versus more than 90% for COVID deaths this year).
(As the ONS release itself says: 'Figures for Influenza and Pneumonia represent where either of these causes have been mentioned anywhere on the death certificate meaning they will not necessarily be the underlying cause of death.')
And finally, from the flu surveillance data, there have actually been almost zero influenza cases in hospitals over the last few months, when levels are very low anyway as it was summer (but also lower than last year – as would be expected due to social distancing, etc. )
This has already been seen in the Southern Hemisphere (eg. Australia) where their winter flu season has been the lowest for years.
But what has been causing the death and suffering of thousands over the last few months is people still staying at home even when they were seriously ill - either to ‘protect the NHS’ or because they were too scared to come to hospital.
We urgently need to improve our public health messaging, and reassure the sick and help them overcome their fear of coming to hospital by providing individual ‘COVID risk calculators’ to help people understand their own risk - which is often overestimated.
And ideally, we need to provide separate COVID units / hospitals to give people more confidence to attend – which also means keeping COVID hospitalisations at a low enough level to enable this
In conclusion, I honestly think comparing COVID to influenza is an unhelpful distraction (it is far more deadly overall and esp. in the over 65s as I showed last week) – the response to COVID should be proportionate to its harms, and balanced against the harm of the response.
The key is to keep focusing on those measures which minimize overall harm – i.e. voluntary social distancing and self-isolation – which is the best way to prevent it being forced upon us through lockdowns.
This week, I will be posting a series of threads on the risks of a second wave - and of our response to it. I hope this will help us overcome the twin dangers of fear and complacency, prevent a second wave - and a second lockdown. This is no. 3: How deadly/dangerous is COVID-19?
There has been a lot of disagreement about how deadly Covid-19 is – with many people hugely overestimating the risk and others insisting it is no worse than flu. We now have much better evidence with actual data (as opposed to modeling) to answer this question.
Firstly, you need to look at the infection fatality rate (IFR) which is the percentage of those INFECTED who die (not just those who are diagnosed as positive cases - which is a huge underestimate of the actual number infected -eg in the UK, we have recorded roughly 400,000 cases
On the risks of a second wave - what can we learn from other countries experience?
The evidence is mixed and between-country comparison have lots of limitations so you can come to different conclusions based on which countries you look at. However, generally it is true that
those countries experiencing larger second waves after lifting lockdowns are those that had smaller first waves so more of their population remain susceptible to infection. But it is not true that the second waves are only causing cases and not deaths eg Israel, Romania, Morocco
The converse is also true (so far) in that countries with large first waves are having smaller second waves, and particularly in cities like New York where 20 per cent of the population has developed antibodies, there is no second wave yet. This was surprising as it was expected
I'm still seeing two widespread misunderstandings of this graph and the data.
The first is that cases are now as high as they were during the first wave – leading to unnecessary fear – and the second is that hospitalisations and deaths (and test positivity) are much lower now than when we had a similar number of cases – leading to unjustified complacency.
These case count (and test positivity) comparisons are completely misleading, because far more tests are being carried out now than in the first wave when they were only being done on those in hospital, not in the community.
💡?Time to ease the lockdown?💡
There are some encouraging signs that we are making good progress on meeting most of the governments five tests to ease the lockdown:
(Thanks to colleagues at CEBM Oxford for collating the data cebm.net/covid-19/covid…)
1. The NHS has sufficient capacity:
Daily hospital admissions for COVID-19 have fallen by 70% since the peak on April 2nd. Number of critical care beds with COVID-19 patients has fallen by >50% since the peak on April 8th and is now 20% (and never reached more than about 55%.)
2. A ‘sustained and consistent’ fall in daily deaths:
Deaths in hospital have fallen by about 70% from the peak on April 8th up to May 6th.