Estimates of excess deaths can provide information about the burden of mortality potentially related to COVID-19, beyond the number of deaths that are directly attributed to COVID-19. Excess deaths are typically defined as the difference between observed numbers of deaths and expected numbers. This visualization provides weekly data on excess deaths by jurisdiction of occurrence. Counts of deaths in more recent weeks are compared with historical trends to determine whether the number of deaths is significantly higher than expected.
Estimates of excess deaths can be calculated in a variety of ways, and will vary depending on the methodology and assumptions about how many deaths are expected to occur. Estimates of excess deaths presented in this webpage were calculated using Farrington surveillance algorithms (1). For each jurisdiction, a model is used to generate a set of expected counts, and the upper bound of the 95% Confidence Intervals (95% CI) of these expected counts is used as a threshold to estimate excess deaths. Observed counts are compared to these upper bound estimates to determine whether a significant increase in deaths has occurred. Provisional counts are weighted to account for potential underreporting in the most recent weeks. However, data for the most recent week(s) are still likely to be incomplete. Only about 60% of deaths are reported within 10 days of the date of death, and there is considerable variation by jurisdiction. More detail about the methods, weighting, data, and limitations can be found in the Technical Notes.
NOTES: Figures include all revisions received from the states and, therefore, may differ from those previously published. Data are provisional and are subject to monthly reporting variation. National data are calculated by summing the number of events reported by state of residence; counts are rounded to the nearest thousand (births and deaths) or hundred (infant deaths). Provisional counts may differ by approximately 2% from final counts, due to rounding and reporting variation. Additionally, the accuracy of the provisional counts may change over time. Data are estimates by state of residence. For discussion of the nature, source, and limitations of the data, see "Technical Notes" of the report, Births, Marriages, Divorces, and Deaths: Provisional Data for 2009. Available from URL: http://www.cdc.gov/nchs/data/nvsr/nvsr58/nvsr58_25.htm. Final counts of births, deaths, and infant deaths for previous years can be obtained from http://wonder.cdc.gov.
SOURCE: Provisional data from the National Vital Statistics System, National Center for Health Statistics, CDC.