I’m deeply saddened to learn that Dr Joseph Sonnabend, one of the most important figures in the history of AIDS, died yesterday. I spent time with him in 2018 for one of the last interviews he ever gave. Let me tell you about this man and what he did:
More from Health
🚨New lockdown regulations just published, in force tomorrow
The Health Protection (Coronavirus, Restrictions) (No. 3) and (All Tiers) (England) (Amendment) Regulations 2021
https://t.co/L5jwlTDaIE
(Thread)
These are not a new set of regulations: they are amendments an old set of regulations
Which we thought were gone! But they are back
Welcome back No.3 regulations
A quick thing before we continue!
I have been analysing these laws for free for 9 months now - if you want to say thanks and have a few £ to spare please give to my @LawCentres fundraiser
They give free legal advice to people who need it
They also amend the All Tiers regulations
Oh god it's all amendments by paragraph references
Basically all of England now in Tier 4 and Tier 4 is amended but not by a huge amount
This really is a terrible way to make laws on the fly - who can possibly understand it?!
So, to explain, you need 2 documents open if you want to understand what is going on:
All Tiers regulations (Tiers 1-4, 2 December as amended) https://t.co/IraPQ112ak
And amendments https://t.co/L5jwlTDaIE
No sensible way of doing except by track changes, on it now, back soon
The Health Protection (Coronavirus, Restrictions) (No. 3) and (All Tiers) (England) (Amendment) Regulations 2021
https://t.co/L5jwlTDaIE
(Thread)

These are not a new set of regulations: they are amendments an old set of regulations
Which we thought were gone! But they are back
Welcome back No.3 regulations
A quick thing before we continue!
I have been analysing these laws for free for 9 months now - if you want to say thanks and have a few £ to spare please give to my @LawCentres fundraiser
They give free legal advice to people who need it
They also amend the All Tiers regulations
Oh god it's all amendments by paragraph references
Basically all of England now in Tier 4 and Tier 4 is amended but not by a huge amount
This really is a terrible way to make laws on the fly - who can possibly understand it?!

So, to explain, you need 2 documents open if you want to understand what is going on:
All Tiers regulations (Tiers 1-4, 2 December as amended) https://t.co/IraPQ112ak
And amendments https://t.co/L5jwlTDaIE
No sensible way of doing except by track changes, on it now, back soon
You gotta think about this one carefully!
Imagine you go to the doctor and get tested for a rare disease (only 1 in 10,000 people get it.)
The test is 99% effective in detecting both sick and healthy people.
Your test comes back positive.
Are you really sick? Explain below 👇
The most complete answer from every reply so far is from Dr. Lena. Thanks for taking the time and going through
You can get the answer using Bayes' theorem, but let's try to come up with it in a different —maybe more intuitive— way.
👇
Here is what we know:
- Out of 10,000 people, 1 is sick
- Out of 100 sick people, 99 test positive
- Out of 100 healthy people, 99 test negative
Assuming 1 million people take the test (including you):
- 100 of them are sick
- 999,900 of them are healthy
👇
Let's now test both groups, starting with the 100 people sick:
▫️ 99 of them will be diagnosed (correctly) as sick (99%)
▫️ 1 of them is going to be diagnosed (incorrectly) as healthy (1%)
👇
Imagine you go to the doctor and get tested for a rare disease (only 1 in 10,000 people get it.)
The test is 99% effective in detecting both sick and healthy people.
Your test comes back positive.
Are you really sick? Explain below 👇
The most complete answer from every reply so far is from Dr. Lena. Thanks for taking the time and going through
Really doesn\u2019t fit well in a tweet. pic.twitter.com/xN0pAyniFS
— Dr. Lena Sugar \U0001f3f3\ufe0f\u200d\U0001f308\U0001f1ea\U0001f1fa\U0001f1ef\U0001f1f5 (@_jvs) February 18, 2021
You can get the answer using Bayes' theorem, but let's try to come up with it in a different —maybe more intuitive— way.
👇

Here is what we know:
- Out of 10,000 people, 1 is sick
- Out of 100 sick people, 99 test positive
- Out of 100 healthy people, 99 test negative
Assuming 1 million people take the test (including you):
- 100 of them are sick
- 999,900 of them are healthy
👇
Let's now test both groups, starting with the 100 people sick:
▫️ 99 of them will be diagnosed (correctly) as sick (99%)
▫️ 1 of them is going to be diagnosed (incorrectly) as healthy (1%)
👇