Stringency index and various 'Covid-19 metrics in Europe (part 2, with lags !)
Follow up but this time using lags for Stringency index (after smart comments on reddit)
All data come from covid.ourworldindata.org / focus on Europe
First analysis is here : https://godlak.substack.com/p/stringency-index-and-various-covid
Overall RĀ² are very small; if we consider RĀ² as a measure of how well a linear (i insist on LINEAR) fit allows to ācaptureā or āexplainā a cloud of points (i.e. empirical observations) then the (linear) links or relationships between Stringency index and various ācovid-19ā metrics in Europe are very weakā¦
But i used the contemporary values of Stringency index in first part; one can argue that stringency (e.g. lockdown) needs ātimeā to achieve its expected goals !
Therefore I replicate first analysis using Stringency index values lagged by 7, 14 and 21 days respectively w/r to āusualā covid-19 metrics: Reproduction rate, Positive rate, New cases per million, Weekly hospi. admission / mil., Weekly ICU admission / mil., New deaths / mil.
Each time i remind the RĀ² from first analysis:
Reproduction rate vs Stringency index in Europe had an overall RĀ² = 2.36%
With longer lags R increases up to 21%, almost x 10
So one could interpret that stringency measures (i.e. NPI) āneed timeā to make a (linear) link appear with reproduction rate (the āfamousā R)
Remember that this R is strongly related to PCR intensity and positivity of PCRā¦
Positive rate vs Stringency index in Europe had RĀ²=3.99%
Lags make it worst, as it goes down to almost 0 with 21 days lag for Stringency index
Here NPI measures are less and less ālinearlyā linked to % PCR+ with timeā¦ Notice that the fitted line becomes then flatā¦
New cases per million vs Stringency index in Europe, RĀ²=1.09%
RĀ² goes down to almost 0 with longer lagsā¦ which makes sense: if you lockdown humans for instance and also lockdown PCR centers you mechanically reduce ācasesāā¦ in that case you can claim lockdown works but the devil is in the detailsā¦
Weekly hospi. admission / mil. vs Stringency index in Europe, RĀ²=1.52%
RĀ² goes down to ~ 0 again; linear link between NPI measures and hospi. becomes inexistant over timeā¦
Weekly ICU admission / mil. vs Stringency index in Europe, RĀ²=0.68%
RĀ² drops to 0 again
New deaths / mil. vs Stringency index in Europe, RĀ²=4.76%
(notice it is the largest overall RĀ² in the previous contemporaneous analysis)
RĀ² drops with every lag, to reach 0.88%
Overall, using these metrics and focusing on RĀ², expect the reproduction rate, all other ācovid-19ā metrics become even less linearly related to stringency index over time; which confirms the need for more analysis if NPI are not eventually completely useless and do more harm if we consider society, economy, and so onā¦