# Racial/Ethnic Disparity in US Covid Infection Rates

Death rates. Here are the updated, officially counted covid deaths per 100K population by race/ethnicity in the United States:

• Overall = 61 deaths per 100K
• White = 39 deaths per 100K
• Black = 93 deaths per 100K
• Hispanic = 60 deaths per 100K

Fatality as lagging indicator of infection. Official death counts probably underestimate the number of fatalities attributable to covid infection. However, the cumulative death rate is the most accurate indicator of the population’s infection rate. Using the IHME’s estimated US covid fatality rate of 0.85% for the US , here are the imputed cumulative infection rates by race/ethnicity:

• Overall = 61/(.0085 x 1000) = 7.2 percent infected
• White = 39/(.0085 x 1000) = 4.5 percent infected
• Black = 93/(.0085 x 1000) = 10.9 percent infected
• Hispanic = 60/(.0085 x 1000) = 7.1 percent infected

Age adjusted fatality rates. The 0.85% fatality rate estimate is an overall average for the US population. Age, however, is a significant predictor of covid mortality; e.g., per the CDC, 65-74 year olds infected with covid are 90 times more likely to die of the disease than are infected 18-29 year olds. All else equal, populations with a higher median age will have a higher mortality rate. Here is median age by race/ethnicity of the US subpopulations:

• Overall = 38 years
• White = 44 years
• Black = 34 years
• Hispanic = 30 years

Based on the CDC’s data, as well as national seroprevalence studies conducted in various countries, each additional year of population median age results in about a 10% higher mortality rate. Conversely, younger populations have a 10% per year lower mortality rate compared to the overall average. The year-by-year age adjustments are geometric rather than linear, compounded annually. So, calculating the age-adjusted covid fatality rates by race/ethnicity:

• Overall = 0.85% fatality rate
• White = 0.85% x 1.16) = 1.51% age-adjusted fatality rate = 1.78 times the overall rate
• Black = .0085/1.14 = 0.58% age-adjusted fatality rate = 0.68 times the overall rate
• Hispanic = .0085/1.18 = 0.40% age-adjusted fatality rate = 0.47 times the overall rate

Age-adjusted infection rates. Combine these intermediate calculations to arrive at cumulative US age-adjusted covid infection rates by race and ethnicity:

• Overall = 7.2 percent infected
• White = 4.5/1.78 = 2.5 percent infected
• Black = 10.9/0.68 = 16.0 percent infected
• Hispanic = 7.1/0.47 = 15.1 percent infected

## 6 thoughts on “Racial/Ethnic Disparity in US Covid Infection Rates”

1. This is the “all else equal” situation for age adjustment. I’m pretty sure that on average blacks and hispanics have higher comorbidities than whites, adding further distress to their corona vulnerability.

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2. In making prevalence estimates based on deaths, I failed to compensate for the time lags. Per the CDC, there’s an average 20-day lag from infection to death, plus another 20-day lag from death to reporting of that death. So the estimates of infection rates should include a projected additional 40 days’ worth of deaths to the cumulative count. At the current rate, that’s an additional 800 deaths per day x 40 = 32,000, or about 10 deaths per 100K population. That’s an increase of 16% overall. So, the age-adjusted estimates by race/ethnicity accordingly should be:
– Overall = 8.4 percent infected
– White = 2.9 percent infected
– Black = 18.6 percent infected
– Hispanic = 17.5 percent infected

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3. “CDC is in the process of a very large, sequential study across the entire United States, measuring serology … the preliminary results on the first round show that a majority of our nation – more than 90% of the population – remains susceptible,” [CDC director] Redfield said.

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