Requirements to replace Ontario PHU datasets with the Ontario Ministry of Health dataset

[jeanpaulrsoucy]

Over the last few weeks, we have been forced to retire some Public Health Unit (PHU) datasets for Ontario which we have relied on since April 1, 2020. The first to fall was Chatham-Kent:

Chatham-Kent (ON) was rewritten (cases, deaths, recovered) back to 2020-04-01 using the Ontario Ministry of Health dataset. Previously we used the PHU’s dashboard, as we do for all other PHUs. However, there are significant discrepancies in cases, deaths and recovered between these two data sources, which made rewriting the whole time series the least disruptive option to the trends in the data.

This was done due to changes in reporting as a result of changes to PCR testing criteria in Ontario as of 2022. These changes in reporting have been replicated across most PHUs, but most changes have allowed us to continue reporting cases, deaths and recovered data as before. However, frequency of reporting has declined for some PHUs.

We have decided on the following criteria for retiring a PHU dataset and replacing it with the Ministry of Health dataset for that specific PHU:

• Changes to data reporting such that cases, mortality and/or recovered cannot be reported as before, OR
• Frequency of reporting drops below 3 times per years

We have decided that retiring 10 PHU datasets (out of 34) will trigger the archiving of all ON PHU datasets and the wholesale replacement of the ON case, mortality and recovered time series with the Ontario Ministry of Health dataset. At the moment, the following ON PHU datasets have been retired:

1. Chatham-Kent
2. Leeds, Grenville & Lanark
3. Eastern
4. Huron Perth
5. York
6. Grey-Bruce
7. Lambton
8. Haliburton Kawartha Pineridge
9. Durham