Homicide rates are valuable to report because they provide specificity to violent crime and injury deaths. High levels of violent crime, including homicide, compromise physical safety and psychological well-being.
Homicides is a Rate
Homicides is the number of deaths from assaults per 100,000 population. Rates measure the number of events (i.e., deaths, births, etc.) in a given time period (generally one or more years) divided by the average number of people at risk during that period. Rates help us compare data across counties with different population sizes.
Deaths are Counted in the County of Residence for the Person Who Died, Rather than the County Where the Death Occurred
It is important to note that deaths are counted in the county of residence of the deceased. So, even if a homicide occurred across the state, the death is counted in the home county of the individual who died.
Some Data are Suppressed
A missing value is reported for counties with fewer than 10 homicide deaths in the time frame.
The numerator is the number of deaths in a county over a 7-year period due to homicide as defined by ICD-10 codes X85-Y09 (assault).
The denominator is the aggregate county population over the 7-year period.
This measure can be used to measure progress with some caveats. It is important to note that the estimate provided in the County Health Rankings is a 7-year average. However, in most counties, it is relatively simple to obtain single-year estimates from the resource included below. Homicide data can also be further broken down by year and method of assault. These breakdowns could help measure the impact of interventions specific to homicide prevention.
Years of Data Used
CDC WONDER mortality data
The Compressed Mortality File (CMF) is a county-level national mortality and population database spanning the years 1968-2017. Compressed Mortality data are updated annually. The number of deaths, crude death rates and age-adjusted death rates can be obtained by place of residence (total U.S., Census region, Census division, state, and county), age group, race (years 1968-1998: White, Black, and Other; years 1999-present: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, and White), Hispanic origin (years 1968-1998: not available; years 1999-present: Hispanic or Latino, not Hispanic or Latino, Not Stated), gender, year of death, underlying cause of death (years 1968-1978: 4 digit ICD-8 codes and 69 cause-of-death recode; years 1979-1998: 4-digit ICD-9 codes and 72 cause-of-death recode; years 1999-present: 4-digit ICD-10 codes and 113 cause-of-death recode), and urbanization level of residence (years 1968-1998: not available; years 1999-present: per the 2006 or the 2013 NCHS Urban-Rural Classification Scheme for Counties).
 Ellen IG, Mijanovich T, Dillman KN. Neighborhood effects on health: Exploring the links and assessing the evidence. Journal of Urban Affairs. 2001;23:391-408.
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