Update to various Covid-19 indicators for England:
• Another big drop in deaths.
• No further rise in Triage whilst Zoe down again.
• Positive tests down (just) overall, no change in school ages
A few other points to note …
1. Daily admissions drops back to 72 for Midlands (16 Mar), making me more suspicious that the leap to 116 on the 15th may have been a data problem.
2. 7-day ave for positive tests goes up to last Sat. Not a “school mass testing” day so not surprising no further increase ...
3. I've switched back to reporting 4-19 for school ages (rather than 10-19) as testing has also ramped up in primaries (though not as much as secondaries).
In any case, 4-19 more relevant going forward in seeing any impact of school opening itself (rather than mass testing) ...
4. Triage & Zoe should now be starting to reflect any effect of school re-opening. Good to see neither increasing in latest day's data, but still very early days of course.
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Although cases have plummeted worldwide since Christmas, most countries in Europe have started to see increases (small so far) in past couple of weeks.
This is true in places with few restrictions (Sweden/Finland) as well as those with strict lockdowns (Denmark/Belgium/Austria).
Czechia is a good example: more or less in lockdown since mid-October though with quite a few specific tightening & relaxations at different times.
Restrictions ramped up even more on 30 Jan, yet cases are rising faster than in most countries. Here is the comparison with Sweden.
Not all countries have seen an increase, e.g.:
Portugal (lockdown) & Spain (no lockdown, varying regional restrictions): still seeing decreases.
Italy (restrictions but no lockdown & some recent relaxing) & France (significant restrictions, no lockdown): fairly stable for now.
1. When there is a surge in infections, cases eventually come down whether or not there is a lockdown/significant restrictions. 2. Lockdowns/many restrictions have little (not necessarily no) impact on hospitalisations & deaths.
Some find this hard to accept, as it seems so obvious:
Transmission comes from contact, restrictions reduce contact, so surely restrictions must reduce transmission & hence admissions & deaths?
But there are lots of reasons why restrictions may have less benefit than expected:
1. People change their behaviour voluntarily in response to changes in infections.
You choose to take less risk when infections surge, more risk when infections low, but just as importantly ...
Restrictions were imposed to stop health services being overwhelmed.
Govt policy on reopening now seems to be based on an assumption that opening 1 thing inevitably increases transmission & so something else has to be kept shut.
There is little support for this in the data ...
E.g. A number of academic papers suggest opening schools has little or no impact on transmission rates:
Changes in prevalence will reflect changes in infections about 2 weeks earlier. Take age 2-year 6 group (mainly primary). Estimated prevalence increased until a peak on 24 Dec (implying infections peaked about 10 Dec). So infections started falling at a time schools were open.
Prevalence falls until 6 Jan (i.e. infections about 23 Dec) & then increases again. i.e. infections in primary kids started increasing again when schools were shut for holidays.
One reason I am sceptical about impact of Tier 3&4 is decline in infections from end-Dec is part of the normal longer run trend we see v. often: when cases rise, rate of growth increases, then declines & eventually goes negative. A bit like R declining but still > 1 for a while.
Here is rate of growth for Zoe estimates for England.
Growth rate turns -ve (i.e. estimated infections start to fall) on data from 3 Jan (implying infections falling perhaps 5-6 days earlier). But growth rate started falling from 16 Dec, i.e. before school hols or Tier 4.
V. little sign of tier changes/lockdown accelerating the trend. In fact, the inflection point around 23-28th Dec happens just when effect of school holidays/T3 then T4 in London/SE/E might have kicked in. Similarly, no sign of any accelerating of trend after lockdown.