Member-only story
Cumulative Cases by Specimen Date
What does the Public Health England data table show?
In the Public Health England dashboard, there is a table of confirmed cases by specimen date. Journalist Robert Peston (ITV) sounded on Twitter:
As you can see it makes no sense at all. There is weird repetition and none of the columns reconcile.
This article aims to make sense of what the data table shows.
Thinking about cumulative cases
There are many graphs in Public Health England’s COVID-19 data dashboard. Among them, there is the total number of lab-confirmed SARS-CoV-2 cases in England. This table is by specimen date.
We need to think about what each line is showing. This is cumulative lab-confirmed cases by the specimen date.
The specimen date is the day that the tested person gave their sample. This is important for understanding the epidemic. Labs may send their analyses across in batches. Measuring cases by reporting date means we would be, in part…
