As the COVID-19 pandemic continues to evolve, comparing disease prevalence by age, race or geographic areas helps analysts understand its spread and plan prevention strategies. Population data is used to calculate infection rates and in cooperation with the Census Bureau, we’ve compiled new age data for all 95 Tennessee counties to help improve the accuracy of age-based COVID-19 rates.
The Tennessee Department of Health (TDOH) provides daily updates on the number of new COVID-19 cases in Tennessee by age group as part of their downloadable datasets. Three age-related files are provided:
- Case counts by 10-year age groups by day
- Case counts by 10-year age groups by day for counties
- Cases age 5-18 years for counties
What can this data tell us?
When case counts are combined with population data for each age group, the rate of infection per 100,000 people can be calculated. Such rates help identify age groups with a greater frequency of cases reported. Rates also can be used to compare similar age groups across different-sized counties.
Charting the change in the total number of confirmed cases per 100,000 people over time shows how rate of COVID-19 infections varies by age group.
For example, between July 1, 2020, and August 1, 2020, the total number of COVID-19 cases in Tennessee grew from 660 per 100,000 people to 1,680 cases per 100,000. But as the chart show, the growth among 21 to 30 year olds was substantially higher over the same time. This age group grew 71% faster than the state as a whole and increased 1,064 per 100,000 people to 2,645 cases per 100,000.
Download 2019 Population by TDOH Age Groups
The U.S Census Bureau’s Housing and Population Estimates provide the most current data for Tennessee and its counties for use in disease incidence rate calculations. But, because the TDOH age groups do not align with the population estimate age breakdown, the Census Bureau’s standard data products cannot be used.
To resolve the alignment issue, we obtained single-year of age population estimates from the Bureau’s Population Division and compiled them into age groups that were compatible with the TDOH’s daily updates. Files are provided in Excel format and include additional detail about the steps used in preparing the modified estimates.