Description

• Injury, intentional or not, is often predictable and preventable. Unintentional injuries are no longer considered “accidents” given that most injuries are preventable.
• As of 2020, unintentional injury is the 4th leading cause of death in the United States. Injury is the leading cause of death for people aged 1 to 44 years, accounting for some 80,000 deaths in 2020. It is also a leading cause of disability for people of all ages, regardless of sex, race/ethnicity, or socioeconomic status. Violence-related deaths accounted for >58,000 deaths in the United States in 2020 (>36,000 suicides and >21,000 homicides).

Epidemiology

Incidence

• Children mostly die of unintentional injuries: motor vehicle traffic (MVT), drowning, poisoning, and suffocation.
• MVT is the most common type of unintentional injury deaths in adolescents.
  ALERT
  Poisoning, which includes drug overdose, has been the leading cause of injury deaths in the United States overall since 2011 and is particularly deadly for persons ages 15 to 64 years, as the leading cause of injury deaths among 25 to 64 years and the second leading cause of unintentional injury deaths for 15 to 24 years.
• Approximately 4.4 million people worldwide die yearly from injuries, of which all forms of violence combine to cause nearly 1/3 of these deaths (World Health Organization [WHO]).
• Unintentional MVT deaths rank third in the United States for overall injury deaths, first in those aged 5 to 24 years and third in those aged 1 to 4 years and 25 to >65 years.
• Among leading causes of injury deaths in the United States, unintentional falls rank third overall. Firearms are related to the fourth and fifth leading causes of injury deaths in the United States, suicide and homicide, respectively.
• Homicide is the second leading cause of death in 2020 for persons aged 15 to 24 years in the United States.

Etiology and Pathophysiology

Multifactorial

Risk Factors

• Motor vehicle accident (MVA):
  • MVT deaths accounted for 40,698 deaths in 2020 with an age-adjusted rate of 11.9 deaths per 100,000 persons (CDC). Each year, approximately 3 million people are nonfatally injured in the United States from motor vehicle crashes (CDC). The leading cause of death for U.S. teens is MVAs (CDC). In the United States, 1 in 3 deaths involved drunk driving and almost 1 in 3 deaths implicated speeding (CDC).
  • Motorcyclists are more likely to die in a motor vehicle crash than car occupants. The risk of death is reduced by 37% with helmets (CDC).
  • Risk factors for involvement in an MVA include high speed, teenage drivers, consumption of alcohol or drugs affecting the central nervous system, fatigue, and distracted driving (handheld mobile phones and inadequate visibility).
  • Increased risk of death by MVA in the United States: not using seat belts, car seats, and booster seats; drunk driving; speeding (CDC)
• Pedestrians:
  • >7,000 pedestrians were killed by motor vehicles and an estimated 104,000 were treated in EDs for nonfatal injuries in the United States (2020; CDC, National Center for Injury Prevention and Control [NCIPC]).
• Bicycles:
  • In the United States, >800 bicyclists died and nearly 357,000 bicycle-related injuries occurred in 2020 (CDC, NCIPC).
  • Risk factors for cyclist injury include age (5 to 19 years for nonfatal injury, 50 to 59 years highest bicycle death rates), male sex, urban area at nonintersection location, and alcohol involvement.
• Sports- and recreation-related injury (CDC):
  • >2.6 million children (0 to 19 years old) are treated in EDs each year.
  • Prevention tips include the following: Use protective gear that is in good condition, fits properly, and worn correctly; sports program and/or school has instituted action plan to teach athletes ways to lower risk of getting a concussion and other injuries; monitor temperature to prevent heat-related injuries; and serve as a role model of safe behavior.
• Drowning: a leading cause of unintentional injury death among all children, particularly those 1 to 4 years of age
  • Children at increased risk include African Americans and those unattended in bathtubs, swimming pools, and recreational water activities (CDC, NCIPC).
• Suffocation: increased risk for children aged <1 year, unsafe sleeping environments (CDC)
• Falls (CDC, NCIPC):
  • The leading cause of nonfatal injuries accounting for >6.5 million nonfatal injuries in the United States in 2020
  • Most common cause of traumatic brain injuries (TBIs)
  • Risk factors for falls include lower body weakness, vitamin D deficiency, difficulties with walking and balance, use of medications (tranquilizers, sedatives, antidepressants, some over-the-counter medicines), vision problems, foot pain or poor footwear, and home hazards (broken/uneven steps, throw rugs, clutter).
• Violence: Risk factors include adverse childhood exposures (ACEs); lack of access to social, capital, community organization, and economic resources; familial instability; community and family violence; access to firearms; mental health; personal or household member alcohol and drug use; exposure to suicidal behavior; history of aggressive behavior; cognitive deficits; poor supervision; poor peer-to-peer interaction; academic failure; poverty; and lower socioeconomic class (CDC).
• Homicide and gun violence: Homicide is the second leading cause of death for persons aged 15 to 34 years in the United States (CDC). Most common victims are young males. Firearms are used in more than half of U.S. homicides.
• Suicide: Females are more likely to have suicidal thoughts, but males are 4 times more likely to complete suicide. Most common methods are firearms for males and poisoning for females (CDC, NCIPC).
• Adolescent violence (CDC):
  • In 2019, nearly 8% of students participated in a physical fight at school in the last year.
  • >9% of high schoolers reported not going to school on ≥1 day(s) in the last 30 days because they felt unsafe at school or on their way to or from school.
  • 4% of students have carried a weapon to school; >7% of students have been threatened or injured by a weapon at school.
• Bullying (CDC):
  • In 2020, 20% of students report being bullied on school property in the last year.
  • >15% of students report cyberbullying.
  • Bullying is associated with social, emotional, and academic difficulties.
• Interpersonal and intimate partner violence (IPV):
  • WHO reports about 38% of female homicides globally were killed by male partners, similar to CDC reports of nearly half of female homicide victims in the United States are killed by a current or former male intimate partner.
  • Approximately 1 in 4 women and almost 1 in 10 men have experienced sexual violence, physical violence, and/or stalking in their lifetime from an intimate partner (CDC).
  • Dating violence among teens:
    • Almost 1 in 11 female and approximately 1 in 15 male high school students report physical dating violence in the last year (CDC).
    • Approximately 1 in 9 female and 1 in 36 male high school students report sexual dating violence in the last year (CDC).
  • Risk factors include individual risk factors (such as low income, young age, heavy alcohol and drug use, depression and suicide attempts, unemployment, being a victim of physical or psychological abuse, witnessing IPV between parents as child, unplanned pregnancy), relationship factors (such as marital conflict, economic stress, association with antisocial and aggressive peers), community factors (such as poverty, low social capital), and societal factors (such as traditional gender norms or gender inequality, societal income inequality).
  • Protective factors include high friendship quality, social support, neighborhood collective efficacy (community cohesiveness, mutual trust, willingness to intervene for the common good), coordination of resources, and services among community agencies.

• The U.S. epidemic of drug overdoses (poisonings) includes >898,000 deaths from 2001 to 2020 from an overdose involving any opioid (prescription and illicit).
• In 2021, >107,500 drug overdose deaths occurred in the United States.
• Opioids, primarily synthetic fentanyl and fentanyl derivatives, are the main cause of drug overdose deaths. In 2021, opioids were involved in 75% of all drug overdose deaths; two out of three opioid-involved overdose deaths involved synthetic opioids.
• Preventive measures of opioid deaths include improve opioid prescribing, reduce exposure to opioids, prevent misuse, and access to naloxone and treat opioid use disorder.