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As COVID19 rates start to increase this article might interest those who've not read it. Relevant well beyond anaesthetists and intensivists. https://onlinelibrary.wiley.com/doi/10.1111/anae.15220
Important to understand how risk changes as incidence does
Risk is of harm from COVID-19 is now informed by several mayor studies including @opensafely @ISARIC1 @ONS & @ICNARC
Here's how they fit together
Worth noting that fewer than 10% of COVID-19 deaths have been in ICU. We see a biased group....
Worth noting that fewer than 10% of COVID-19 deaths have been in ICU. We see a biased group....
Risk is an interaction between
Exposure (proximity and duration of contact with an infected person)
Mitigation of exposure risk
Individual susceptibility to harm if infected
I've tried to illustrate their dynamism here
Exposure (proximity and duration of contact with an infected person)
Mitigation of exposure risk
Individual susceptibility to harm if infected
I've tried to illustrate their dynamism here
Importantly mitigation is key to preventing harm as many previously shielded staff (and patients) may now be in hospitals https://icmanaesthesiacovid-19.org/workplace-shielding-and-doctors-at-higher-risk-of-harm-working-in-anaesthesia-and-critical-care-during-the-covid-19-pandemic
Arguably mitigation of risk ot healthcare staff is reduced by two recent changes
First NICE guidance that elective patients need only to isolate for 'up to 72 hours'
https://www.nice.org.uk/guidance/ng179/chapter/3-Minimising-the-risks-associated-with-COVID-19#all-planned-procedures-needing-anaesthesia-general-regional-and-local-or-sedation
First NICE guidance that elective patients need only to isolate for 'up to 72 hours'
https://www.nice.org.uk/guidance/ng179/chapter/3-Minimising-the-risks-associated-with-COVID-19#all-planned-procedures-needing-anaesthesia-general-regional-and-local-or-sedation
This is difficult to follow: we know incubation period is around 5 days, viral secretion <9 days and most disease transmission occurs in days 0-5 of infection including in asymptomatic patients
(So 14 days makes most sense - as it does for travel quarantine & self isolation)
(So 14 days makes most sense - as it does for travel quarantine & self isolation)
Excellent paper here on viral dynamics https://www.medrxiv.org/content/10.1101/2020.07.25.20162107v2
The second issue is the new PHE guidance which also reduces mitigation by removing transmission based pathways (eg airborne PPE) from low-risk COVID (green) pathways
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/910885/COVID-19_Infection_prevention_and_control_guidance_FINAL_PDF_20082020.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/910885/COVID-19_Infection_prevention_and_control_guidance_FINAL_PDF_20082020.pdf
So it is important to map individual risk and environmental risk (exposure/mitigation) when considering personal risk .
Many risk scores don't do this
Many risk scores don't do this
The paper offers a possible alternative risk tool
Finally don't forget that amongst all risk factors age pretty much trumps them all
Importance of age was emphasised by @d_spiegel yesterday on @BBCr4today
