Alberta's new COVID stats page can be confusing. Here are the key numbers — and what they mean

Alberta's new respiratory virus dashboard provides weekly updates on the spread of COVID-19 in the province, but making sense of the numbers can be a challenge — and it's particularly difficult to figure out how many people have died.

For example, Albertans who visited the dashboard in mid-November were greeted by a front-page "highlights" package informing them there had been two deaths from COVID-19 during the past reporting week.

That was technically true.

Equally true — but less obvious — was the fact that there were actually 18 more deaths in that week's report, compared with the report from the week before.

How can both numbers be correct?

Here's what's going on.

Of the 18 additional deaths included in that week's report, just two occurred during the reporting week of Nov. 5 to 11.

That's pretty typical, given how long it takes for COVID deaths to be recorded and included in the provincial data. The process can often takes weeks, sometimes more than a month.

This reporting lag means many of the deaths in each weekly report actually happened in prior weeks.

Nowhere on the site, however, was it made explicit that 18 more people had died, in total, including those from prior weeks.

To figure that out, a visitor would have to recall the total number of deaths cited in the previous week's report, then subtract that from the total number of deaths in the most recent report.

The province's decision to present the data in this way can create a misleading picture, says Craig Jenne, a professor in the department of microbiology, immunology and infectious diseases at the University of Calgary.

"We see this number that seems really small, and it maybe leads to a false sense of security," he said.

"We've seen, almost without variance, numbers going up in subsequent weeks."