Methodology

Updated: May 2024

Firearm Deaths

Fatal injury data come from the Centers for Disease Control and Prevention (CDC)’s National Vital Statistics System (NVSS). The CDC compiles this data from death certificates, which are provided by vital registration systems from state and local jurisdictions.

EveryStat uses CDC data from the Wide-ranging ONline Data for Epidemiologic Research (WONDER), 2018–2022 underlying cause of death by single-race categories and 1999–2020 underlying cause of death by bridged-race categories databases.

Version: The most recent data from the CDC published on EveryStat is for 2022. Unless noted, and in order to account for normal fluctuations that occur between years, deaths are a five-year average of the years 2018 to 2022. Age-adjusted rates calculated by the CDC are used, except for analyses focused on specific age groups or at the county-level and for analyses of intimate partner homicides. For these analyses crude rates are used.

 

Intimate Partner Homicides

Statistics of intimate partner homicides (IPHs) among women aged 18 years or older are based on data from the CDC’s National Violent Death Reporting System (NVDRS). This is one of the few sources of homicide data that includes information about the relationship between the victim and offender. Participation in NVDRS has been growing over time: in 2020, 48 states and the District of Columbia submitted data for at least some counties. The national number of IPHs was obtained by applying the aggregate rate across the 48 states and the District of Columbia to US population counts of women aged 18 years and older. Similarly, for states with partial NVDRS coverage, IPH rates were applied to state population totals to estimate the number of IPHs for the entire state. Statistics on IPH are not provided for the two nonparticipating states (Florida and Hawaii). Rates of firearm IPH by race and ethnicity are not calculated if the denominator was less than 10,000 women aged 18 years or older to avoid unstable rates.

Version: The most recent data from NVDRS published on EveryStat is for 2020. Race and ethnicity rates are based on one (2020) to up to five (2016 to 2020) years of data depending on how long the state has participated in NVDRS, in order to have as much data as possible to produce stable estimates.

 

Firearm Homicides and Fatal Shootings by Police

While the CDC is considered to be the most comprehensive source for data on fatal firearm injuries, research shows its data on “legal intervention” (i.e., shootings by police or other law-enforcing agents) are greatly underreported and are often misclassified as homicides. To account for this, with the exception of the “Gun Deaths by Intent” pie chart, data on firearm homicides have been combined with shootings by police. 

To highlight the extent of this problem, the “Gun Deaths by Intent” pie chart includes a note with data on fatal shootings by police from the Mapping Police Violence database. 

Version: The most recent data from the CDC published on EveryStat is for 2022. Unless noted, and in order to account for normal fluctuations that occur between years, deaths are a five-year average of the years 2018 to 2022. Age-adjusted rates calculated by the CDC are used, except for analyses focused on specific age groups or at the county-level. For these analyses crude rates are used. The most recent data from Mapping Police Violence published on EveryStat is from 2023. In order to account for normal fluctuations that occur between years, deaths are a five-year average of the years 2019 to 2023.

 

Transgender Homicides

Data on the homicide of transgender and gender expansive people in the US and Puerto Rico are gathered by Everytown for Gun Safety through media reports. In this analysis, “transgender” and “gender expansive” identities include any victim who lived or identified as a gender different from that which was ascribed to them at birth.

Version: The data from the Everytown Transgender Homicide Tracker published on EveryStat is updated in real-time.

 

Nonfatal Firearm Injuries

Data on nonfatal firearm injuries are based on hospital discharges from the Agency for Healthcare Research and Quality’s (AHRQ) Healthcare Cost and Utilization Project (HCUP).

Everytown analyzes multiple data sets purchased through the HCUP Central Distributor to calculate nonfatal injuries

  1. National Emergency Department Sample (NEDS) of emergency department visits.
  2. National Inpatient Sample (NIS) of inpatient hospital admissions.
  3. State Emergency Department Databases (SEDD) for 27 states.
  4. State Inpatient Databases (SID) for 32 states.

Version: The most recent data on nonfatal injuries published on EveryStat are from 2020, the most recent national- and state-level estimates available from HCUP.

 

Economic Cost of Gun Violence

Data on the costs of gun violence are constructed from the calculation:

Total cost = cost per nonfatal injury or death x number of injuries and deaths

Costs per fatal and nonfatal injury are based on research by Ted R. Miller and other researchers at the Pacific Institute for Research and Evaluation. Costs to society include out-of-pocket payments for medical care, mental healthcare, emergency transport, police response, criminal justice and incarceration, employer costs, work loss for victims and perpetrators, and lost quality of life. Costs to taxpayers include government payments for medical care, mental healthcare, emergency transport, police response, criminal justice and incarceration, Medicaid, and Social Security Insurance payments. Further methodology of these unit costs is available from the Methodological Note.

The number of nonfatal firearm injuries used to calculate the total cost of gun violence for states was estimated from the 2019 Healthcare Cost and Utilization Project (HCUP) data on hospital emergency department and inpatient files (see Methodological Note). The number of firearm deaths used to calculate the total cost of gun violence for states was obtained from the CDC WONDER online database for 2019. 

Version: The most recent data on costs of gun violence published on EveryStat are in 2019 US dollars, based on 2019 firearm deaths and 2019 nonfatal firearm injuries.

 

Population Denominators

  • For national, state, and county-level deaths, population denominators are from CDC’s WONDER according to its single race and ethnicity categories.
  • For nonfatal injuries, population denominators are provided by HCUP.
  • For fatal shootings by police, population denominators are from the Census (including midyear estimates), accessible through https://data.census.gov/.

Suppressed, Unreliable, and Missing Data

Updated: May 2024

In order to protect individual identities, the CDC and AHRQ do not report data when the number of deaths or nonfatal injuries is fewer than or equal to 10 for any subnational estimates. For the calculation of percentages, when the numerator was fewer than 10, this is indicated as less than 5% or less than 1%. Further, the CDC considers population rates unreliable (large coefficients of variation) when the number of deaths or nonfatal injuries is fewer than or equal to 20. Data that are suppressed or considered unreliable have not been included in EveryStat.

Demographics

Updated: May 2024

Racial and ethnic categories in EveryStat are as defined by the CDC and considered “single-race.”  EveryStat contains six separate, mutually exclusive racial and ethnic categories.

American Indian/Alaska Native = American Indian / Alaska Native, non-Latinx

Asian/Pacific Islander  = Asian, non-Latinx + Native Hawaiian or Other Pacific Islander, non-Latinx

Black = Black, non-Latinx

Latinx = American Indian / Alaskan Native Latinx + Asian Latinx + Native Hawaiian or Other Pacific Islander Latinx + Black Latinx + white Latinx + more than one race Latinx

White = white, non-Latinx

More than one race = More than one race, non-Latinx

 

Children and teens are defined as individuals between the ages of 0 and 19 years. In statistics regarding the “leading causes of death,” however, children and teens are defined as those between the ages of 1 and 19. This distinction is made because the leading causes of death for newborns and infants less than 1 year of age are considerably different from those 1 year and older.

Analysis and Calculation

Updated: May 2024

Crude rates 

Crude rates were either obtained directly from the CDC or were calculated by Everytown by dividing the number of cases by the population denominator and multiplying by either 100,000 or 1,000,000.

Age-adjusted rates 

Age-adjusted rates per 100,000 people were obtained directly from the CDC and not calculated by Everytown.

Percent change = (new value – previous value) / previous value 

Percent change is used to compare new values to previous values. This formula is used when looking at the percentage increase or decrease.

Ranking

Rankings are based on all 50 states and Washington, DC, with 1st being the highest and 51st being the lowest. Firearm death rankings are based on age-adjusted rates. Nonfatal injury rankings are based on crude rates. Economic cost rankings are based on the average societal per-resident cost.

Hours between gun suicide deaths = 24 / average daily gun deaths

The number of hours between gun suicide deaths was calculated by dividing 24 (i.e., the number of hours in a day) by the average number of gun deaths each day. The daily average gun suicide deaths was calculated by dividing the yearly average by 365.25 days, which accounts for leap years. Averages are based on five years of most recent available data from the CDC: 2018–2022. Hours were converted to minutes if the result was less than one hour, or converted to days if the number of hours was greater than 72 hours.