dcyphr | Temporal Trends and Racial/Ethnic Inequalities for Legal Intervention Injuries Treated in Emergency Departments: U.S Men and Women Age 15-34, 2001-2014


In this study, the researchers analyzed U.S data about injuries inflicted by police and private security guards to understand trends over time and by race/ethnicity.


Police violence/brutality is a medical and public health concern. Public health and medical professionals have called for more research about the health consequences of policing. Recent research has examined relationships between racial discrimination by police on health, as well as how public health surveillance can be used to provide more data about police-related deaths and injuries.

However, basic epidemiological questions about police violence have not been answered. These questions include how the number of injuries related to police brutality has changed over time, or how many of these injuries are classified as “legal interventions” in hospitals according to the International Classification of Diseases (ID). There has also been little research on how private security guards use excessive force and cause injury, because they are not included in the ICD definition of legal intervention.

In this study, the researchers analyzed data about injuries caused by police and private security guards who were treated in emergency departments (EDs). In doing so, they tried to understand how many of these injuries happen, whether the number of injuries has changed over time, and whether the rate of these injuries happening varies by race/ethnicity.


From 2001-2014, there were 683,033 legal intervention injuries treated in EDs. 14.3% of these injuries belonged to women, and 86.5% belonged to men. For a small number of cases, gender was unknown and excluded from the study.

The rate of legal intervention injuries increased from 2001-2014 by 47.4%. Men experienced a 50.8% increase and women experienced a 26.2% increase.

Analysis of racial/ethnic differences found that black people were 4.90 times more likely to experience legal intervention injuries than white people. The rate at which black people experienced legal intervention injuries was similar for both men and women. The calculated rate differences demonstrate that if black people experienced legal intervention injuries at the same rate as whites, there would have been 242,320 less injuries from 2001-2014.

Estimates for the number of legal intervention injuries experienced by Hispanic people and other people of color were unreliable due to a high coefficient of variation. Although the estimate for Latinos for legal intervention injuries was higher than white people, the difference was not statistically significant.


The researchers found that legal intervention injuries are an important contributor to ED visits in people aged 15-34, especially for men. For men, the number of legal intervention injuries was similar to the number of people injured by motor vehicle accidents. In addition, the number of ED visits due to legal intervention injuries increased from 2001-2014, more for men than for women. Finally, black people were found to be 4.90 times more likely to be subjected to legal intervention injury. This is consistent with previous studies that found that black people are more likely to experience police violence and die from legal intervention injuries.

Limitations of this study include a high level of missing data, and also the lack of data of how legal intervention injuries were treated during the ED visits. There was also no data as to whether the use of force that caused these injuries was legally justified.


The researchers used data from the National Electronic Injury Surveillance System-All Injuries program (NEISS-AIP), which collects data about ED visits in 66 U.S hospitals. Collected data includes demographic characteristics of gender, age, and race/ethnicity. These visits are categorized in four kinds of injuries, including legal intervention. A visit is categorized as a legal intervention when an injury was inflicted by police or other legal authorities (including private security guards) while trying to enforce the law.

The data from the NEISS-AIP was accessed through the CDC. Data was available from 2001-2014, and had sampling/survey design accounted for to create nationally representative estimates for the number of injuries. The researchers restricted the data to ages 15-34, who were the highest risk for legal intervention injury, and made up 61.1% of legal intervention injuries over the study period.

Stata was used to analyze the data using linear regression. The researchers tested for trends in rates of legal intervention each year. They also calculated the rates and differences in rates in black, Hispanic, and other populations of color and compared them to those of white people. They conducted all analyses for both the entire population and also by gender.


Legal intervention injuries harm the individual, their families, and their communities. It is important for public health officials to monitor the prevalence of these injuries. This monitoring can provide data for the public that improves understanding of how large the issue of police violence is and whether it is getting better or worse over time.