3 ms·

I don't see anything about sampling bias here. I would assume that people who have been ill, experienced mild symptoms, or who were exposed to confirmed cases w

I don't see anything about sampling bias here. I would assume that people who have been ill, experienced mild symptoms, or who were exposed to confirmed cases would be more likely to respond to the facebook ads recruiting testing volunteers. I'm sure we are significantly undercounting cases but I highly doubt we are off by a magnitude of 50x.

brink 7y ago
I know. 50-85x is hard to believe. How could we be that far off?
- jplayer01 7y ago
  It’s not hard to believe when you consider testing criteria.
- gfodor 7y ago
  The # of cases reported that I believe they are comparing against is the number of confirmed positive tests, not the number of assumed cases in the county based on some other model that is trying to project # infected. I don't think anyone thought that we had 100% coverage where all cases were tested. So we're not "wrong" if such a study as this sees a gap between reported confirmed cases and expected infected, it just means we have a better understanding of the testing gap, which is self evident in existence but the magnitude of which we don't know. Given all the other factors, an order of magnitude or more gap between tests and sick people doesn't seem completely out of the question. I would be curious if there are other models using a different methodology which could help us get a handle on the conditional probability chain leading to tests being done or not on an individual, to see if there is a similar set of conclusions.
- usaar333 7y ago
  It's impossible to believe. Currently, Santa Clara's crude CFR is 3.7%. NYC has similar demographics (and as bad nursing home hits?) -- 0.14% of the population has died from covid. That puts an upper bound of 26x (and that's if the entire population was infected)
  - irq11 7y ago
    You have no reason to believe that the Santa Clara CFR is correct, and dividing the CFR of one city by the IFR of another is meaningless.
gfodor 7y ago
They mention it, but state it's hard to ascertain. I agree with that assessment. Given the magnitude of the delta between confirmed cases and projected cases based on this study tho, it seems intuitively obvious there's a pretty big gap. (And not surprising, given the lack of testing, the asymptomatic nature of the disease, etc.)
all_usernames 7y ago
If the vast majority of people contracting the virus never have symptoms, or have symptoms mild enough that they don't seek a doctor, or they DO seek a doctor but can't get a test because of testing criteria restrictions, I think the 50-85x number starts to make a lot of sense.

brink 7y ago

I know. 50-85x is hard to believe. How could we be that far off?

jplayer01 7y ago
It’s not hard to believe when you consider testing criteria.
gfodor 7y ago
The # of cases reported that I believe they are comparing against is the number of confirmed positive tests, not the number of assumed cases in the county based on some other model that is trying to project # infected. I don't think anyone thought that we had 100% coverage where all cases were tested. So we're not "wrong" if such a study as this sees a gap between reported confirmed cases and expected infected, it just means we have a better understanding of the testing gap, which is self evident in existence but the magnitude of which we don't know. Given all the other factors, an order of magnitude or more gap between tests and sick people doesn't seem completely out of the question. I would be curious if there are other models using a different methodology which could help us get a handle on the conditional probability chain leading to tests being done or not on an individual, to see if there is a similar set of conclusions.
usaar333 7y ago
It's impossible to believe. Currently, Santa Clara's crude CFR is 3.7%. NYC has similar demographics (and as bad nursing home hits?) -- 0.14% of the population has died from covid. That puts an upper bound of 26x (and that's if the entire population was infected)
- irq11 7y ago
  You have no reason to believe that the Santa Clara CFR is correct, and dividing the CFR of one city by the IFR of another is meaningless.

gfodor 7y ago

They mention it, but state it's hard to ascertain. I agree with that assessment. Given the magnitude of the delta between confirmed cases and projected cases based on this study tho, it seems intuitively obvious there's a pretty big gap. (And not surprising, given the lack of testing, the asymptomatic nature of the disease, etc.)

all_usernames 7y ago

If the vast majority of people contracting the virus never have symptoms, or have symptoms mild enough that they don't seek a doctor, or they DO seek a doctor but can't get a test because of testing criteria restrictions, I think the 50-85x number starts to make a lot of sense.