The Curve? Did we flatten the curve?

For 7 weeks, I have been tracking COVID-19 data in Canada and maintaining comparisons with Italy. Initially I wanted to understand a potential path for Canada's case volumes. Since we are now beginning to loosen restrictions, I wanted to take stock of the current situation. You can download the report at the following link:

Early time-adjusted data comparing Italy and Canada was incredibly close. Canada's interventions were put in place around March 14-15th and did not materialize in Canada's data for the subsequent two week period.

Things changed for Canada's case rate relative to Italy between March 30th and April 1st as a gap opened between Canada's actual cases and the time-adjusted forecast based on Italy's data.

From that point on, the gap between Canada and Italy's cumulative cases has steadily grown.

Did We Flatten the Curve?

Government graphs depicting the idealized 'curve' typically form an arc. On that basis, my assumption has been that public policy interventions are being measured against the new case rate curve since the cumulative case curve never actually declines.

With that assumption, I have been plotting Canada's new case rate v. Italy's (below). This shows that Canada has maintained a lower new case rate which indicates to me that Canada has flattened the curve at the national level and this flattening effect materialized around March 31st.

What I see in Canada's data v. Italy's is that although the national numbers went 'lateral', they are not declining at the same pace that Italy's did from their peak.

The Regional Situation

Like Italy, COVID-19 has not had a uniform impact across all regions in Canada. Several weeks ago, I observed a spike in Quebec's case rate, so I started looking at the provincial numbers more closely.

It became clear that Canada's national new case rate is disproportionately influenced by Quebec. Yesterday, Quebec's cases accounted for 61% of Canada's new cases while Quebec represents approximately 22% of the country's population:

Things changed in Quebec around April 14th

Quebec's case rate jumped off the Italian 'curve' on April 14th. Since then, Quebec's new case rate per 100K has been well above Italy's. My data indicates Italy's highest one day new case rate per 100K was 10.8. Quebec's rate has been higher than 10.8 for 6 days since April 14th.

Quebec's early March Break seems to explain why Quebec's case rate was higher through the first month of the outbreak. The cause of the case rate jump following April 14th is not as obvious, and I have no personal theories to explain this.

Isolating Quebec's cases from the rest of Canada, the trend is promising although for the past two weeks Ontario's new case rate has been stuck between 347 and 525 (average 434). That range is low, but the data suggests Ontario's rate is 'stuck' at that level.

The Trough?

Excluding the exceptional situation in Quebec, I feel we could be in a 'trough' on the 'curve' because restrictions are cautiously being lifted. With such prolonged social isolation and economic disruption, further moves to loosen restrictions are inevitable.

Sweden v. Quebec

I have done an analysis comparing Quebec with Sweden. The two share similar population scales and metropolitan population density. This has been an interesting comparison because of the much publicized minimal interventions imposed by the Swedish government. Comment if you are interested in seeing the Sweden/Quebec analysis and I will share it once I have more data.