Thread by @danamlewis

THREAD:

I have been asked in a few DMs about how to assess individual risk with #COVID19, and while I talked about it in a previous thread (

https://twitter.com/danamlewis/status/1234278377248288769?s=20

), here’s my attempt to explain it further:

1/ We currently have 3 pieces of information.

A: Death rates by age groups for those with #COVID19
B: Death rates by comorbidity for those with #COVID19
C: Newer, hazard ratio for 1 or 2 comorbidities that is a ratio of risk for hospitalization, ventilation, & death *combined*

2/ This means that the third piece of information, the hazard ratio, is a *broader* piece of information about risk of a *severe* case or outcome of #COVID19. Despite being a combined endpoint, it gives us a useful approximation of how to adjust the risks of any single outcome.

3/ To assess my individual risk of a severe outcome, I am looking at my age group risk of death with #COVID19 (e.g. 0.2%) and applying the hazard ratio of having one comorbidity (type 1 diabetes, so 1.59x). Therefore, 0.2%x1.59 is 0.3%.

So how am I using this information?

4/ First, this calculation helps me contextualize against “B” information (death rates by comorbidity). For diabetes (all types combined), it’s 7.3%. Compared to my “A” information (age group death rate, 0.2%), that’s a big spread and left me feeling uncertain.

5/ Therefore, the “C” information helps confirm the hypothesis that my risk of death if I get #COVID19 *is* still relatively close to my age group. So I am less worried about a severe case personally (than before), while still doing what I can to prevent getting it at all.

6/ However, in older age groups with much higher risk rates (e.g. an 80-year old with 1-2 comorbidities), their already high risk rate and any comorbidities, the C information really drives home how careful our community needs to be to help protect them from getting #COVID19.

7/ Again, none of this is saying what risk for getting #COVID19 is, but about the likely outcomes are if you do get a case. 80% are estimated to be relatively mild. But for me, the above information is helpful for calculating the risk of being in the other 20% if I get #COVID19.

8/ So what can you do to prevent getting #COVID19? Wash your hands. If you’re sick, or have a sick family member, stay home or work from home when possible. Distance yourself from the community where possible. (More in this thread here:

https://twitter.com/danamlewis/status/1233974451978436608?s=20

)

9/ Summary: the hazard ratios are useful for assessing risk of a *severe* case (hospitalization, ventilation, or death), and better understanding the scary-sounding comorbidity death data that is *only* broken down by age group or comorbidities, not both.

10/ Regardless of personal risk level of a severe case, we should all be increasing hand hygiene, staying home when sick, and protecting other members of our community by helping cut down and reduce transmission of #COVID19 (along with colds and the flu).