This chart shows the evolution over time of the ‘excess severity ratio’ across World Bank regions.
The excess severity ratio relates excess mortality accrued over the course of the COVID-19 pandemic to the level and profile of pre-pandemic mortality. The ratio itself is defined simply as the ratio between (1) the total number of estimated daily excess deaths (averaged over the course of a week) and (2) the total number of reported daily all-cause deaths in 2019 (averaged over the course of a year). Note that all-cause mortality from 2019 is averaged yearly in the interest of having a globally comprehensive sample.
The excess death estimates are derived from the excess death model by The Economist. We use the mid-point estimates that their model generates. Note that there may be a wide band of uncertainty around these estimates.
The excess severity ratio thus makes a comparison with the level of 2019 mortality. It compares excess mortality during the pandemic with all-cause mortality in 2019 over the same interval of time. If the ratio is, say, 10% then we can say that excess mortality corresponds in magnitude to about a 10th of the dying that happened in 2019 over a similar interval of time.
In the above chart, we focus purely on the evolution of the excess severity across World Bank regions and don’t make any comparisons with the top causes of death in 2019. See the related charts below for such comparisons.
Note that the expression of mortality in relative terms is a useful way to communicate the severity of the pandemic. Countries will have adapted to their specific patterns of mortality. Deviations from this pattern may create pressure points, such as on the health system. Comparisons with previous patterns give a country-specific and intuitive flavor of the severity of the COVID-19 pandemic. A statement such as “the excess mortality toll currently amounts to more lives lost than the loss of life due to the top cause of death n 2019” may convey a better feel for the severity of the pandemic than a reference to a crude mortality rate (total deaths per 100k people).
Pandem-ic uses the World Bank income classification as a major building block in the analysis of the impact of the pandemic.
The income classification groups countries in four buckets by per capita income levels: high-income countries (HICs), upper-middle-income countries (UMICs), lower-middle-income countries (LMICs) and low-income countries (LICs). We use the current FY2022 classification, which determines the thresholds of the buckets as follows:
See here for a dynamic visualization of how the income classification of countries has changed over time through the current FY2022 classification
A good part of this site also analyzes the pandemic by region (where we use the World Bank regional classification and the UN geo-scheme of subregions). In both cases (i.e. across income groups and regions), the universe of countries is based on the World Bank income classification. More on that in the next note.
The universe of countries on this website is determined as follows.
Note that the vaccination data is pulled from Our World in Data, which utilizes a slightly different universe of locations. In sticking with the above 196 countries and economies, we have made the following adjustments relative to the OWID universe.
For each of the above adjustments to the vaccination data, we make adjustments to the demographic data that vaccine information is related to (including population size, age structure and priority group size).
Finally, note that no adjustments are required to the totals for France as its overseas territories and dependencies are already included.