Please help connect May and September antibody data; there appears to be an error about coronavirus-data

[mmontesanonyc]

Thanks for the question.

The answer lies in the fact that, per documentation, the data are person-level. That means that the data are not the number of tests, but the number of people tested.

Since many people get tested more than once, over time, it's possible to add more people positive without adding more people tested: somebody who initially tested negative, but later seroconverted and got tested again would appear in the data as a new "person testing positive" but not as a new "person tested."

[laurarpg]

How could we use this data then to approximate the percent of New Yorkers currently seropositive?

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On May 11, 2022, at 12:09 PM, M. Montesano ***@***.***> wrote:  Thanks for the question. The answer lies in the fact that, per documentation, the data are person-level. That means that the data are not the number of tests, but the number of people tested. Since many people get tested more than once, over time, it's possible to add more people positive without adding more people tested: somebody who initially tested negative, but later seroconverted and got tested again would appear in the data as a new "person testing positive" but not as a new "person tested." — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.

[mmontesanonyc]

These data can't help approximate the percent of New Yorkers currently seropositive. They're too heavily influenced by testing bias. There's no reason to assume that those who have chosen to get tests is a representative sample of all New Yorkers, and cumulative data on nearly 2 years of antibody testing can offer very limited insight into who is currently seropositive.