To determine how COVID-19 is being underreported in every state, 24/7 Wall St. calculated the total number of reported COVID-19 deaths as a percentage of excess deaths from all causes using data from the Centers for Disease Control & Prevention. The CDC uses historical data from 2013 to the present to estimated excess deaths, which represent the difference between the observed number of deaths in a given week and the expected number of deaths for that week based on CDC projections. The CDC weighs data on observed deaths to account for reporting lags and potential underreporting of deaths from all causes by jurisdiction.
24/7 Wall St. reviewed the number of excess deaths that occurred from Mar. 1 to May 9, 2020, in each state and compared it to the state’s reported number of COVID-19 deaths over the same period. Assuming that every COVID-19 death in 2020 is an unexpected excess death, we considered the difference between excess deaths and reported COVID-19 deaths to be not accounted for deaths, and the potential result of underreporting of COVID-19-related deaths. Due to data limitations, we looked at the period Mar. 1, 2020 to Apr. 25, 2020, for North Carolina and Apr. 5, 2020 to Apr. 25, 2020, for Connecticut.
Data on reported COVD-19 deaths, as well as positive, negative, and total test counts as of May 18, 2020, came from various state and local health departments and were adjusted for population using data from the Census Bureau’s 2018 American Community Survey. Data on land area by state used to calculate population density also came from the Census Bureau.