Number of deaths among residents under age 18 per 100,000 population. The 2023 County Health Rankings used data from 2017-2020 for this measure.
The child mortality rate can have a large impact on years of potential life lost (YPLL), so it is an important measure to reference when interpreting a county's YPLL rate.
Data and methods
National Center for Health Statistics - Mortality Files
Data on deaths and births were provided by NCHS and drawn from the National Vital Statistics System (NVSS). These data are submitted to the NVSS by the vital registration systems operated in the jurisdictions legally responsible for registering vital events (i.e., births, deaths, marriages, divorces, and fetal deaths). In prior years of the Rankings, Premature Death was calculated by the National Center for Health Statistics, but this year the Mortality-All County (micro-data) file was requested. This allowed us to calculate Premature Death and Life Expectancy ourselves. While most calculations of mortality rates can be downloaded from CDC WONDER, the calculation of Years of Potential Life Lost and Life Expectancy requires raw data files.
Key Measure Methods
Child Mortality is a rate
Child Mortality measures the number of deaths occuring before age 18 per 100,000 population. Rates measure the number of events (e.g., deaths, births) in a given time period (generally one or more years) divided by the average number of people at risk during that period. Rates facilitate data comparisons across counties with different population sizes.
Child Mortality is a rare event (statistically speaking)
Child death is a relatively rare event in most counties. Counties with smaller populations can see a lot of relative change in child death rates from year to year. Such changes are usually due to normal variation and are not necessarily caused by any actual change in the underlying risk of child death in the county. To help determine if the child death change in a county is due to normal variation or real change, we recommend examining the provided error margins. Error margins are statistical tools that aid interpretation of variation in measures. If the error margins overlap year to year, it’s less likely that the variation in Child Mortality reflects real underlying changes in community health.
What deaths count toward Child Mortality?
Deaths are counted in the county of residence, regardless of where the death occurred.
Some data are suppressed
A missing value is reported for counties with fewer than 10 child deaths in the time frame.
The numerator is the number of deaths occurring before the age of 18.
The denominator is the total population under the age of 18.
Can This Measure Be Used to Track Progress
This measure can be used to track progress with some caveats. Child death is a relatively rare event, especially in small counties. Statistics depend on large numbers of events to detect small changes, meaning that small changes in small communities may be difficult to detect. It is also important to note that the estimate provided in the County Health Rankings is a 4-year average.
Finding More Data
Disaggregation means breaking data down into smaller, meaningful subgroups. Disaggregated data are often broken down by characteristics of people or where they live. Disaggregated data can reveal inequalities that are otherwise hidden. These data can be disaggregated by:
We recommend starting with the CDC Wonder database, which contains information on death rates by race, ethnicity, age, gender, geography, cause of death, and more. Rates can be exported as crude or age-adjusted. Small counties might need to combine multiple years of data to see rates, as CDC suppresses any rates when there are fewer than 10 deaths.