Thread by @JPSoucy

As of today, @TOPublicHealth will report new #COVID19 data only on Mondays, Wednesdays, and Fridays. This comes shortly after Quebec’s quickly-reversed decision to transition to weekly rather than daily updates. In this thread, I will argue TPH should restore daily updates.🧵

The #GTA is the epicentre of the #COVID19 epidemic in Ontario. As the country reopens, we must remain vigilant regarding the trajectory of the disease. The decision for #Toronto to provide less regular updates will make this picture needlessly murkier.

The official reasoning from TPH is that as daily case counts decline, daily numbers are less meaningful. There is some truth to this—we do have a tendency to seize upon individual numbers (the noise) rather than longer-term trends (the signal).

toronto.ca/wp-content/upl…

But this ignores the amazing work by so many researchers, journalists, and members of the public to use these data to create visualizations and summaries to better understand the trends arising from the daily numbers.

This is fundamentally an issue of #transparency and #OpenData. TPH has done an excellent job keeping us informed up until now and should maintain the current standard as we inch toward stage 3 of reopening.

This decision isn’t as consequential as what Quebec recently proposed (weekly updates). The delays in receiving new data will only be a few days at most. But there is little reason to purposely degrade the quality of the data that so many people rely on to stay informed.

Our team at the COVID-19 Open Data Working Group certainly uses these numbers every day to keep our #COVID19 #Canada #OpenData current.

github.com/ishaberry/Covi…

We use date of public reporting in our data, since this is the only consistent date between all of Canada’s health regions. This also avoids the issue of backdating new cases.

Many tools rely on our data to be updated daily. They will be affected too. To name a few, @imgrund’s Ontario re-opening metrics, @CoulSim’s regional trends, and rt-canada.ca.

TPH pulls its daily case numbers from the same system it inputs its case data into every day. The data to produce daily updates will continue to be entered regardless of whether they are being publicly reported 3 times a week or every day.

It’s a question of pulling the data and posting it on the website. I do not know if they will be forwarding data to the provincial system (iPHIS) every day or only 3 times per week.

Alternative solutions here are unsatisfactory. We could retroactively update previous days of data based on updates from TPH, but the problem here is that “report date” on the TPH dashboard is not public reporting date, but rather the date the lab sent the case to TPH.

It can sometimes take multiple days for a case to be actually entered into the system and be publicly reported from the day it was received from the laboratory (“report date”).

So newly reported cases will often be backdated to previous days, since those are the “report dates” by the Ministry definition. This is why our case time series does not line up with the one from TPH (we use their daily cumulative case number).

What about the provincial time series? (Again, I’m not sure if they will be submitting to the province daily) Well, this time series also does not line up with the TPH time series.

data.ontario.ca/dataset/confir…

This is due to differences in extraction times and because it reports only confirmed cases, whereas TPH reports confirmed and probable cases together. This is why the provincial data has ~1,300 fewer cases in Toronto than TPH.

The press release from TPH acknowledges there may be another surge in cases in the fall. At minimum, we will see further localized outbreaks, very likely in Toronto. Circumstances may yet force TPH to return to daily updates in some form.

Let’s hope TPH makes the right decision before that happens. #Transparency is an essential part of the public health response. It makes us feel like public health interventions are something we are all a part of, rather than something that is being done to us.

The cost of transparency here is very low. I call on @TOPublicHealth to maintain their existing high standard of data transparency by continuing to release #COVID19 #OpenData on a daily basis.

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