On May 4, 2020, ISTAT (Italian institute of Statistics) reported death counts for 4433 municipalities over Italy, in the periods January 1-April 15 2020 together with median values of deaths counts in the same municipalities for the same period in the years 2015-2019. The data for 2020 was collected with exceptional speed and only the municipalities that passed a quality control standard are included. This allows us to explore the possible exceptionality of 2020, during which there is a COVID epidemic.

We note that the data is limited in a number of ways. The 4433 municipalities represent only a fraction of the population in Italy (there are a total of 7904 across Italy, and the 4433 cover 57% of the Italian population), and differently distributed in the regions.

In the displays that will follow and that are based on data for the 4433 municipalities, whenever possible without decreasing readability, the transparency of colors is proportional to the proportion of population per region or per province that lives in municipalities not included in this subset (more intense colors correspond to better covered region). Another limitation is that the period up to April 15 includes only a portion of the deaths attributed to COVID-19 in the 2020 epidemic (even if this is a much larger portion than the one in the previously released dataset which included mortality up to March 21st)

With these caveats in mind, we are now ready to compare the deaths counts in the 4433 municipalities over the 6 years reported. We start with an overall look of the data from each municipality, which indicates an excess of municipalities with positive relative increment in the death counts in the first 3.5 months of 2020 over the median of the preceding 5 years.

Because looking at single municipalities is challenging, we group them by the regions or the province to which they belong. It is important to keep in mind that regions differ in population size: we then report both counts per 1000 residents (to put regions all on the same “scale”) and total counts (to get a measure of the size of the difference in mortality). Colors used to represent regions are consistent throughout. We start with anoverall view of mortality per 1000 residents.

The following is another illustration of the same data, where rather than displaying the total population in the reporting municipalities, we emphatize which proportion of the regions’ population the reporting municipalities cover.

We now turn to absolute death counts, starting by comparing the total deaths in 2020 in Italy with the reference values.

Looking more specifically at the counts in the individual regions. For each region, the first bar (with a broken line on the perimeter) represents the reference counts, and the second the 2020 counts.

Let’s relate now the “excess” mortality in 2020 and the reported COVID-19 deaths. We only have COVID-19 death counts for regions, so we need to do this comparison at this level of aggregation. The GitHub site of the Protezione Civile which daily updates COVID-19 cases and death counts reports separately the two special provinces who make up the Trentino/Sudtirol region, so we need to pay a little attention to this.

We are now going to focus on the provinces of the Lombardia region, which is the one with the highesr reported cases and deaths from COVID-19, and the one whose overall death count has changed more dramatically. We start with an overall view of the death counts

Here is a detail of the per-capita deaths in the different provinces

And here a detail of variation in deaths counts