Read on Twitter
Graphs like the ones below scare me. I can't see how one can spin this as anything other than a disaster in the making. https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html
People often complain that I'm looking at cases instead of some other metric: hospitalizations, deaths, contestants on the Bachelor who test antibody positive, whatever.
"Positive cases are determined by testing."
"You can't compare April to June."
"Deaths are what matter."
"Positive cases are determined by testing."
"You can't compare April to June."
"Deaths are what matter."
I look at cases for two primary reasons.
1) They are a leading indicator. Deaths lag cases by 2-3 weeks, at which point it's too late.
2) Cases are the causal drivers of new cases. Cases now are the best predictor of cases in a week.
1) They are a leading indicator. Deaths lag cases by 2-3 weeks, at which point it's too late.
2) Cases are the causal drivers of new cases. Cases now are the best predictor of cases in a week.
It's true that changes in testing make it difficult to directly compare case numbers between early April and late June.
But that's not what I'm interested in. I don't all that much care whether we're above the peak of the initial spike. What I care about is where we are going.
But that's not what I'm interested in. I don't all that much care whether we're above the peak of the initial spike. What I care about is where we are going.
So what I want to do is compare cases in Florida today with cases in Florida a week ago. Barring extraordinary circumstances, testing doesn't ramp up exponentially the way that cases have. On the timescale of a week, testing changes are usually a wash.
"What about deaths? Why shouldn't we care about these at least as much as cases? Deaths are not increasing in Florida."
Not yet, that's true.
But deaths are a severely lagging indicator or at least three reasons.
Not yet, that's true.
But deaths are a severely lagging indicator or at least three reasons.
1) It takes 2-3 weeks to progress from infection to death.
2) It often takes a week or more for deaths to be registered.
3) If the leading edge of a spike is driven by younger people, you need one or more rounds of transmission to reach a vulnerable population. But you will.
2) It often takes a week or more for deaths to be registered.
3) If the leading edge of a spike is driven by younger people, you need one or more rounds of transmission to reach a vulnerable population. But you will.
So the trajectory of deaths tells me about how who was infected a month ago was changing, a month ago.
I want to know how who is infected now is changing now, and what that bodes for the future.
I want to know how who is infected now is changing now, and what that bodes for the future.
