COVID Tracking Project Data Inaccuracies 6/22/20
Updated: Jun 24, 2020
I am attaching pdfs that display the spread of COVID-19 both through the entirety of the pandemic and from June 1st through June 21st. Most aggregators of pandemic data appear to be using the date a given case/test/death was entered, rather than when they actually occurred. Note that all figures presented are population weighted per million, rather than raw totals.
Cummulative Deaths, Cases, and Tests per Million (Data: COVID Tracking Project)
The COVID Tracking Project (CTP) is reporting that Arizona has observed 56887 tests/million, 7100 cases/million, and 181 deaths per million through the entirety of the pandemic. However, AZDHS sources differ considerably on the testing count, and slightly on case counts. AZDHS has 78260 tests/million (CTP under-reports by 28%), 7397 cases/million and 181 deaths/million. Using CTP data would cause one to conclude erroneously that the positive test rate in AZ is much higher than actually reported.
June 2020 Deaths, Cases, and Tests per Million (Data: COVID Tracking Project)
Over the month of June, the results are somewhat weirder. Due to reporting its data by day of entry rather than occurance, The CTP figures (and consequently, the incorrect "at the margin" analysis presented by most media outlets) present a very distorted view of the pandemic's progression in June, when viewed against AZDHS figures. From June 1-22, the CTP reports 26366 tests/million, 4398 cases/million, and 58.7 deaths/million. Over the same period, AZDHS reports 30062 tests/million (CTP under-reports by 12%), 4199 cases/million (CTP over-reports by 5%), and 36.3 deaths per million (CTP over-reports by 62%) .
Due to the mass-confusion about COVID reporting, It seems we cannot trust the shape of the data presented to us, even if the cumulative totals are (relatively) accurate.