Age-adjusted death rates are weighted averages of the age-specific death rates, where the weights represent a fixed population by age. They are used to compare relative mortality risk among groups and over time. An age-adjusted rate represents the rate that would have existed had the age-specific rates of the particular year prevailed in a population whose age distribution was the same as that of the fixed population. Age-adjusted rates should be viewed as relative indexes rather than as direct or actual measures of mortality risk. However, you can select other standard populations, or select specific population criteria to determine the age distribution ratios. Premature death rate includes all deaths where the deceased is younger than 75 years of age. 75 years of age is the standard consideration of a premature death according to the CDC's definition of Years of Potential Life Loss. Starting with the 2019 vintage, the CDC no longer calculates rates for a county when the death count is less than 20, marking them as "unreliable." FRED records these instances as missing observations in the series. For more information see the Frequently Asked Questions about Death Rates (https://wonder.cdc.gov/wonder/help/cmf.html#Frequently%20Asked%20Questions%20about%20Death%20Rates).

The crude death rate is the number of deaths reported each calendar year divided by the population, multiplied by 100,000. Premature death rate includes all deaths where the deceased is younger than 75 years of age. 75 years of age is the standard consideration of a premature death according to the CDC's definition of Years of Potential Life Loss. Starting with the 2019 vintage, the CDC no longer calculates rates for a county when the death count is less than 20, marking them as "unreliable." FRED records these instances as missing observations in the series. For more information see the Frequently Asked Questions about Death Rates (https://wonder.cdc.gov/wonder/help/cmf.html#Frequently%20Asked%20Questions%20about%20Death%20Rates).