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. Author manuscript; available in PMC: 2021 Jul 29.
Published in final edited form as: J Behav Med. 2019 Aug 1;42(4):724–740. doi: 10.1007/s10865-019-00035-2

Table 2:

Synthesis of Results, According to Type of Firearm Exposure and Type of Study

First author (year) Population Sample Size Primary Outcome Main Findings Limitations/Notable Strengths
Peer/Partner Violence
Retrospective Cohort Chong, VE (2015a) Patients treated at trauma center for injuries due to interpersonal violence between 2005–2010, median age 20 1,890 Recurrent violent injury

  • 62% of sample had firearm injury at index visit

  • Patients with firearm-related injuries at index event had significantly higher rates of recurrent violent injury than all other injury mechanisms (OR 2.28)

  • Patients from low socioeconomic status neighborhoods more likely to have recurrent violent injury than patients from high socioeconomic status neighborhoods (OR 1.48)

 Single center; approximation of socioeconomic status; chart review
Davis, J.S. (2013) All patients admitted to a level 1 pediatric trauma center with violent injury between 1991 and 2010, age 0–19 12,235 Recurrent violent injury

  • Rate of recurrent admission for injury after an initial penetrating trauma (firearm injury or stabbing) was twice that of patients with an initial blunt trauma (2.4% versus 1.2%)

  • 69% of patients with a recurrent injury who were initially treated for a firearm injury, were also injured by a firearm on their next admission.

  • 85% of deaths after a second injury, were due to firearm injuries. Recidivist death rates were highest for initial GSWs (15%), followed by stab wounds (4%), and motor vehicle accidents (2.9%)

 Single center; chart review
Tellez, M.G. (1995) Admissions to trauma center for violent injury from 1991–1993, age <25 552 Characteristics of recidivists, cost of reinjury

  • Among patients admitted for violent injury, 16% had had a previous violent injury (of whom 28% had had prior firearm injuries)

 Single center; chart review
Prospective Cohort (with random control group) Carter, P.M. (2015) 14-to-24-year-olds with drug use in the past 6 months presenting to urban trauma center with assault injury (n=349; n=70 with firearm injury) matched to 250 controls (drug-using nonassaulted youth) 599 Subsequent firearm aggression or victimization within 24 months of baseline assessment

  • In the full sample, 59% of exposure group reported violent firearm aggression, victimization, and/or firearm injury within 2 years after index ED visit compared to 42.5% in the control group (59.0% vs 42.5%; relative risk = 1.39; P < .001). Of those reporting firearm violence (n = 252), 96.4% (n = 243) reported victimization, including being threatened/shot at with a firearm (n = 238; 94.4%), sustaining a firearm injury requiring ED care (n = 19; 7.5%, mean ISS = 7.0), or death from a firearm (n = 2).

  • Among those who presented with firearm-related injury at index visit (n=70), 82% reported subsequent firearm violence

 Single center (but extremely high follow-up)
Sensitivity analysis Chong, V.E. (2015b) Markov model of outcomes of patients aged 12 to 20 presenting to urban trauma center with violent firearm injury, based on examination of all patients treated for violent injury 2005–2008 155 One year violent injury recidivism; cost-effectiveness

  • 2.5% recidivism rate among injured patients participating in violence intervention program compared to 4% recidivism rate among patients in usual care group (p 0.52)

  • Incremental cost of program = $2,941/QALY

 Non-randomized convenience sample; single center; unreported follow-up rate
Suicide and Self-Harm
Retrospective Cohort Brent, DA (1993a) Close friends and acquaintances of 26 adolescent suicide victims between 1988–1991, age-race-gender matched to controls from communities without recent adolescent suicides 146 Depression (K-SADS-E), PTSD (PTSD-RI), suicidal ideation and attempts, in the 7 months following peer suicide

  • 80% of adolescent suicides were by firearm

  • Exposed group was more likely than controls to have past psychiatric disorder (63% v 35%, p<0.00001)

  • Exposed were more likely to have new onset major depression (29% v 4.8%), PTSD (5.5% v 0%), and suicidal thoughts (6.8% v 2%) in the 7 months since the suicide event (p<0.01 for all), but not more likely to attempt suicide

 Low participation rate (but standardized interviews)
Brent, DA (1993b) 28 high school students exposed to a peer suicide on a bus compared to 28 demographically similar peers from another community 56 Depression/Anxiet y (K-SADS-E), PTSD (Post Traumatic Stress Disorder Reaction Inventory) assessed 2 months after event

  • Exposed group had higher rates of new onset psychiatric disorder (28% vs 4%, p=0.01), anxiety disorder (18% vs 0%, p=0.03) and PTSD (14% vs 0%, p=0.05)

  • Effect was moderated by closeness to both the victim and the event itself, as well as family history of suicide and other external stressors

 Small sample (but Standardized interviews)
Olfson, M. (2018) 12–24 year olds in Medicaid Analytic Extract from 2001–2007 with clinical diagnosis of self-harm 32,395 Repeat non-fatal self-harm or suicide in the year following index event

  • Adolescents who presented with self-injury from firearms were significantly more likely to die from suicide within a year compared to adolescents who presented with nonviolent self harm (adjusted HR 33.45, 95% CI 13.31–84.06). No difference in non-fatal self-harm rates was observed

 Limited to patients receiving Medicaid; relies on hospital billing codes (but excellent outcome capture)
Mass Shooting
Qualitative or cross-sectional Hawkins, N.A. (2008) Students (age 15–17) and parents (age 41–49) from Columbine High School in 1999 11 Qualitative analysis of emotional, cognitive, social responses in the weeks following the shooting

  • The 4 interviewed students and 7 interviewed parents reported both negative emotions (nervousness, guilt, irritability) and positive emotions (strong sense of social ties, feelings of affection towards family and friends) emotions. They overall had negative reaction to media coverage

 Small convenience sample; non-standard qualitative methods
Nader (1990) Long-term follow up of the original sample from Pynoos (1987) 100 Score on the DSM-III PTSD Reaction Index 14 months following the sniper attack

  • Although symptoms decreased compared to one-month follow-up, there continued to be a relationship between proximity to the shooting and continuing post traumatic stress symptoms on the PTSD Reaction Index

 Non-systematic sample (but validated assessments)
Omar, H.A. (1999) Students age 15–17 from 2 high schools in Lexington, KY 412 Emotional responses 10 days following Columbine shooting

  • 80% of surveyed adolescents felt “sad” about the shooting, 16% disgusted, 13% outraged, 3% indifferent

 Convenience sample; non-standardized assessments
Pynoos (1987) Students (age 5–13) exposed to a sniper attack on the school playground 159 Score on the DSM-III PTSD Reaction Index one month following the sniper attack

  • Among the 15% of the student body that was sampled, proximity to the shooting was strongly related to acute stress symptoms as reported on the PTSD Reaction Index

  • Moderate to severe PTSD was reported by 77% of youth who were on the playground at the time of the attack, vs 17% of those who were on vacation

 Non-systematic sample (but validated assessments)
Schwarz, E.D. (1991) Children and adults exposed to shooting at an “upper middle class” suburban elementary school 128 PTSD at 8–14 months post-shooting (DSM III criteria), using self-report measures

  • Among respondents (21% of total potential sample), 50% of children met liberal threshold for PTSD diagnosis, 27% met moderate threshold, 8% met conservative threshold

  • 39% of parents met liberal threshold for PTSD diagnosis, 19% met moderate threshold, 3% met conservative threshold

 Non-systematic sample (but validated assessments)
Prospective Cohort Bugge, I. (2015) Survivors of 2011 mass shooting at youth summer camp in Norway 325 Post traumatic stress symptoms (measured using PTSD-RI)

  • Among respondents (58% of survivors), rates of post-traumatic stress symptoms differed between non-injured (43.8%) and moderately or severely injured (62.2%, 60.9% respectively), with higher levels of symptoms for youth with higher levels of injury (p<0.05 for all)

 Non-systematic sample (but validated assessments)
Dyb, G. (2014) Survivors of 2011 mass shooting at youth summer camp in Norway 325 Correlation between use of by nationally deployed mental health services and mental health symptoms (post-traumatic stress, depression/anxiety, and somatic illness)

  • Among respondents (66% of survivors), 86.9% reported outreach by crisis team; 65.2% reported using the services of a general practitioner; and 73.1% reported receiving specialized mental health services from a psychologist or psychiatrist

  • Survivors receiving specialized mental health services had higher levels of post traumatic stress symptoms, depression/anxiety and somatic illness. They reported lower rates of outreach from the crisis team

  • 13.7% of survivors reported that they had received inadequate support

 Non-systematic sample (but validated assessments)
Hafstad, GS (2014) Survivors of 2011 mass shooting at youth summer camp in Norway 325 Post traumatic stress disorder, measured using PTSD-RI (DSM IV and V criteria)

  • Among those interviewed (66% of survivors), prevalence of PTSD 6 months following shooting (assessed using strict criteria) was 11.1% by DSM IV and 11.7% by DSM 5

 Non-systematic sample (but validated assessments)
Haravuori, H (2011) Survivors of 1 school shooting in Finland in 2007, compared to youth from another high school 231/526 Post traumatic stress symptoms (measured using Impact of Events Scale)

  • Responding survivors (49% of those exposed) who had been interviewed by a journalist had higher IES scores than those not interviewed, or than those not exposed. Those who watched more media reported subjectively feeling worse, but had similar IES scores (after adjustment for severity of exposure and demographics)

  • Youth from the comparison community with greater media exposure did NOT have higher IES scores

 Non-systematic sample (but validated assessments)
Haravuori, H (2016) Survivors of 2 school shootings in Finland in 2007 and 2008, mean age 17.6 228 Post Traumatic Stress Disorder (assessed using K-SADS-PL)

  • Among respondents (26% of all exposed), rates of PTSD at 16 months post-incident ranged from varied by diagnostic criteria: 22.8% (DSM-IV), 37.3% (ICD-10), 28.9% (three-factor ICD-11), and 32.5% (two factor ICD-11)

 Non-systematic sample (but validated assessments)
Stene, L. E. (2015) Survivors of 2011 mass shooting at youth summer camp in Norway 285 Health services utilization and mental health symptoms

  • Among respondents (57.3% of survivors), higher levels of mental distress and higher levels of somatic symptoms at 4 months post-shooting were associated with mental health utilization at 14 months after the attack

 Non-systematic sample (but validated assessments)
Stensland, S.O. (2018) Survivors of 2011 mass shooting at youth summer camp in Norway, matched to controls from population based Young-HUNT3 study 1,917 Recurrent migraine and tension-type headache

  • Survivors who responded to the interview (59% of all survivors) had a significantly higher rate of migraines (aOR 4.27, 95% CI 2.54–7.17), tension-type headaches (aOR 3.39, 95% CI 2.22–5.18), and overall headaches (aOR 3.26, 95% CI 2.22–4.79) compared with non-exposed youth, even adjusting for terror, severity of injury, psychological distress, and demographics

 Non-systematic sample (but validated assessments)
Suomalainen, L. 2011 Survivors of 1 school shooting in Finland in 2007, compared to youth from another high school 231/526 Post traumatic stress symptoms (measured using Impact of Events Scale)

  • Responding survivors (49% of those exposed) had significantly higher odds of post-traumatic stress (aOR 3.8, 95% CI 2.4–6.1) and post-traumatic stress disorder (aOR 6.0, 95% CI 3.5–10.5), as well as higher overall rates of psychiatric distress, at 4 months post-incident, D39compared with non-exposed youth, after adjustment for demographics and perceived social support

  • Rates of substance use were similar among survivors and non-exposed youth

 Non-systematic sample (but validated assessments)
Thoresen, S (2016) Parents of survivors of 2011 youth mass shooting in Norway 531 Post traumatic stress symptoms and depression/anxiety assessed at 4–5 months and 14–15 months following the event, using self-report measures (PTSD-RI and HSCL)

  • Among respondents (65.5% of parents of survivors), the mean PTSD-RI score was 5x higher for parents of survivors than expected based on general population means at wave 1 (4–5months after the shooting). PTSS symptoms improved by wave 2 (14 months after the shooting), but was still 4x higher than would be expected

  • The depression/anxiety score of survivors’ parents was 3x higher than would be expected at wave 1, and 2.5x higher at wave 2

 Non-systematic sample (but validated assessments)
Unintentional Injury
Retrospective Cohort Ponzer, S. (1997) All non-fatal accidental firearm injuries in children under 18 in Stockholm from 1972–1993 (n=141), age and gender matched to controls, mean age 13.2 282 Injury recidivism, hospitalization, conviction of crime

  • Higher rates of hospitalization due to subsequent injury (OR 2.42) and other diseases (OR 4.0)

  • Higher rates of criminal conviction (OR 2.33 for all crimes, OR 6.33 for assault and battery)

  • Higher rates of future imprisonment (OR 14.0)

 Determination of intent by chart review (but systematic sample, excellent follow-up)
Unspecified/Mixed
Cross sectional Slovak, K. (2001) Rural public school students in grades 3–8 in 1998 in Ohio, mean age 11.4 549 Anxiety, depression, PTSD, anger, dissociation (measured by Trauma Symptom Checklist for Children)

  • Respondents (80% of eligible) who reported gun violence exposure in the last year (75% of sample) had significantly higher levels of anger, dissociation, and PTSD, after adjustment for potential covariates

 Cross-sectional (but strong sampling, validated assessments)
Retrospective Cohort Carter, P.M. (2017) Children <19 yo presenting to 16 Pediatric Emergency Departments between 2004–2008 with firearm injuries of any type 1,758 Recurrent injury in the next 12 months

  • 51.4% of injuries were due to assault, 33.2% were “unintentional” (per chart review)

  • 20% of patients had been seen in the ED in the preceding year for any reason

  • 22.4% returned to the ED within the next twelve months for any reason; <1% (n=13) returned for second firearm injury

 Chart review (but multi-center)
Gill, A.C. (2002) Pediatric patients 12 months-17 years treated at a multidisciplinary trauma clinic following hospitalization for traumatic injury, mean age 8.55 337 Post traumatic stress disorder (DSM IV)

  • 40 patients had firearm injuries (12%); patients with firearm injuries had a significantly higher rate of PTSD (45%) at some point in the year after injury, compared with patients with other injury mechanisms

 Single site; only hospitalized patients presenting to trauma clinic
Prospective Cohort Bergman, B. (1996) All non-fatal pediatric firearm injuries from 1972–1993 in Stockholm, age and gender matched to uninjured controls, mean age 13.9 yrs 192 Recurrent injury, hospitalization due somatic injury or psychiatric illness, conviction of crime

  • Childhood firearm injury victims more likely than controls to be hospitalized in the future for any reason (55% vs 37.5%)

  • 16.4% of rehospitalized patients were admitted for psychiatric disorders compared to 1.2% of controls

  • 32.3% of injured patients convicted of crime compared to 7.3% of controls

 Chart review (but excellent follow-up rates)
Boynton-Jarrett, R. (2008) NLSY- Nationally representative sample of adolescents aged 12–18 at baseline followed for 8 years (1997–2004) 8,224 Self-rated health (SRH)

  • Cumulative Exposure to Violence (CEV) score estimates the number of self-reported violence exposures (including gun violence, bullying, robbery, arson)

  • CEV score had a graded effect on SRH; CEV >5 associated with 4.63 times the odds of poor self-rated health. Youth with gun violence exposure were more likely to have poor self-rated health than those without violence exposure

 Non-validated measures of gun violence exposure (but strong sampling methods)
Gibson, P.D. (2016) Patients 0–18 presenting evaluated by the trauma service for any type of firearm injury from 2000–2011 896 Recurrent firearm injury

  • 8.8% of patients had another firearm injury over the following 12 years, and 0.9% had multiple firearm injuries

  • Individual risk factors for recurrent firearm injury included: male, African American

  • Neighborhood risk factors for recidivism included: median income, % unemployed, child poverty rate

 Single center, non-standard follow-up
Hamrin, V. (1998) All patients admitted to pediatric trauma center from June 1994-Sept 1995 with firearm-related injury, ages 11–15 16 Acute stress disorder (DSM III criteria)

  • 56% of children met criteria for acute stress disorder within 24 hours of their injury; the most common symptoms were flashbacks, anxiety and sadness

 Small sample; likely assessing trauma prior to the event as assessed too early for ASD
Hamrin, V. (2004) Patients admitted to pediatric trauma center for firearm injury between 1995–1999, matched to medically hospitalized controls, mean age 14.7 56 Acute stress disorder (ASDS) (measured by Child Posttraumatic Stress Disorder Reaction Index)

  • 75% of patients with firearm injuries screened positive for acute stress disorder within 2 days of their injury, compared to 14% of medically admitted patients

 Convenience sample; non-standardized assessment; assessed too early for ASD