epidemiology of major trauma and trauma deaths in los angeles county

Epidemiology of Major Traumaand Trauma Deaths in Los Angeles County

Demetrios Demetriades, MD, PhD, FACS, James Murray, MD, Bonnie Sinz, RN, Deidre Myles, RN,Linda Chan, PhD, Lakshmanan Sathyaragiswaran, MD, Thomas Noguchi, MD,Frederick S Bongard, MD, FACS, Gill H Cryer, MD, and Donald J Gaspard, MD, FACS

Background: Our objective was to study population-based trauma-related injuries and deaths in the countyof Los Angeles and to identify trends and progress to-wards meeting the “Year 2000 National HealthObjectives.”

Study Design: We did a retrospective study for the year1996. Data were obtained from the Trauma Registry ofthe Emergency Medical Services of the Department ofHealth Services, and the Coroner’s Department of theCounty of Los Angeles. Traumatic injuries and deathsper 100,000 of the population were calculated accordingto mechanism, race, age, and gender.

Results: During 1996, there were 12,136 major traumaadmissions in the 13 trauma centers in Los AngelesCounty. Another 1,929 victims died at the scene or werecertified dead at nontrauma centers and were taken tothe Coroner’s Department (total 14,065 victims). Theoverall major injury rate was 151.0 per 100,000 popu-lation and the death rate was 30.9 per 100,000. Thetrauma death rate per 100,000 population was 56.4 forAfrican-Americans, 33.5 for Hispanics, 26.3 for Cauca-sians, and 11.6 for Asians.

Homicides were the leading cause of traumatic deaths(45.3%) followed by traffic accidents (31.9% of deaths).Firearms were responsible for 3,899 major injuries ordeaths (41.7 per 100,000 population). The overall ho-micide rate per 100,000 population was 14.0, with amuch higher rate for African-Americans (40.4 per100,000) and Hispanics (18.7 per 100,000) than Cau-casians (4.0 per 100,000) or Asians (3.4 per 100,000).African-American males were at very high risk for homi-cide (73.3 per 100,000), and in the age group 15 to 34

years, this problem reaches epidemic proportions (164.2per 100,000).

Traffic accidents accounted for 69.0 major injuriesand 9.6 deaths per 100,000 people. Males were at sig-nificantly higher risk of dying in traffic accidents thanfemales. People over 60 years of age were at significantlyhigher risk of traffic-accident death than younger peo-ple, for both passenger and pedestrian groups(p < 0.01).

Firearm-related suicides were responsible for 4.6deaths per 100,000 population. Caucasian males over65 years were at much higher risk of suicide by penetrat-ing trauma (29.5 per 100,000) than were Hispanics (6.3per 100,000), Asians (5.4 per 100,000), or African-Americans (no deaths) in the same gender and agegroup.

Conclusions: Trauma remains a major health problemin the county of Los Angeles. Despite the significantreduction of intentional trauma in 1996, it still exceedsnational figures and is much higher than the targeted“Year 2000 National Health Objectives.” Aggressiveprevention strategies need to focus on the populationgroups at excessive risks of injury by assault, traffic ac-cidents, and suicides. (J Am Coll Surg 1998;187:373–383. © 1998 by the American College of Sur-geons)

Periodic reevaluation of the epidemiology of fataland nonfatal traumatic injuries is essential for qualityimprovement purposes, redistribution of emergencymedical services resources, and adjustment of pre-vention efforts. In the current manuscript, we ana-lyzed all major injuries and trauma deaths in LosAngeles County in 1996.

Los Angeles County is the most populous countyin the United States with an estimated population of9,373,955 in 1994.1 The Emergency Medical Ser-vices (EMS) is the largest in the country with 13trauma centers, 40 public and private paramedic pro-vider services, and 2,300 paramedics. Six of the

Received March 20, 1998; Revised June 4, 1998; Accepted June 8, 1998.From the Division of Trauma, Department of Surgery, University of SouthernCalifornia (Demetriades, Murray); Emergency Medical Services, Departmentof Health Services of Los Angeles County (Sinz, Myles); Department of Epide-miology and Biostatistics, LAC 1 USC Medical Center (Chan); Coroner’sDepartment (Noguchi, Sathyaragiswaran); Harbor-UCLA Medical Center(Bongard); UCLA Medical Center (Cryer); and Huntington Memorial Hospi-tal (Gaspard), Los Angeles, CA.Correspondence address: D. Demetriades, MD, PhD, HCC, University ofSouthern California, 1510 San Pablo St., Suite 514, Los Angeles, CA 90033.

373© 1998 by the American College of Surgeons ISSN 1072-7515/98/$19.00Published by Elsevier Science Inc. PII S1072-7515(98)00209-9

trauma centers have “secure catchment areas” andaccept patients from strict geographic boundaries.The other seven trauma centers have “open catch-ment areas” and receive patients from any locationprovided the transport time is , 20 minutes; air am-bulances are used if ground transport time is . 20minutes. Trauma victims are transported to the near-est trauma center. Patients with airway obstructionproblems or cardiac arrest from blunt trauma or ex-trathoracic penetrating injuries are transported to thenearest hospital. All admissions to trauma centersmeeting the criteria for major trauma definition (Ta-ble 1) are entered into the Trauma Registry, which iscontrolled by the EMS of the Department of HealthServices (TEMIS System).

The purpose of the present study was to performa population-based surveillance of both fatal andnonfatal traumatic injuries and identify trends overtime.

METHODSThe study included all traumatic deaths and

trauma registry patients in the county of Los Angelesfrom January 1, 1996 to December 31, 1996. Datawere recovered from the trauma registry database ofthe EMS of the Department of Health Services andthe Coroner’s Department of the County of Los An-geles. Criteria for inclusion in the trauma registry arelisted in Table 1. Minor traumas not fulfilling the

registry criteria were not included. Also excludedfrom the study were deaths due to burns, drowning,or poisoning.

Statistical AnalysisInjuries and traumatic death rates per 100,000

population were derived from 1994 population esti-mates for the county of Los Angeles from the USBureau of the Census.1 Age-gender-ethnic specifictrauma mortality rates were derived for Los AngelesCounty for four age groups (under 15, 15 to 34, 35to 54, and 55 to 74) and four ethnic groups (Cauca-sian, African-American, Hispanic, and Asian). Table2 shows the population and ethnic distribution inLos Angeles in 1994. Crude and adjusted relativemortality risks and 95% confidence intervals com-paring gender and ethnic groups were derived andtested for statistical significance using the eqidemiol-ogy software EPI-INFO, version 6 (Centers for Dis-ease Control and Prevention, Atlanta, GA). No at-tempts were made to analyze mortalities per traumacenter because this information is outside the scopeof this study, and the different types of trauma seenby the various trauma centers may make any com-parisons misleading.

RESULTSDuring 1996 there were 12,136 major trauma

admissions to the 13 designated trauma centers inLos Angeles County. Another 1,929 victims were

Table 1. Standard Criteria for Major Trauma

Adults with systolic blood pressure , 90 mmHg or childrenwith systolic blood pressure , 60 mmHg

No spontaneous eye openingPenetrating cranial injuryPenetrating thoracic injury between the midclavicular linesGunshot wounds to the trunkBlunt injury to the chest, with unstable chest wall (flail chest)Penetrating injury to neckDiffuse abdominal tenderness following blunt traumaPatient surviving falls from heights . 450 cm (. 15 ft)Intrusion of the motor vehicle into the passenger space

Table 2. Population and Race Distribution of LosAngeles County, July 1994*

Population %

Caucasian 3,374,246 36Hispanic 3,736,866 40Asian/Islander 1,143,976 12African-American 1,062,408 11Native American 59,359 1Total 9,373,955 100

*US Bureau of the Census, 1994.

Table 3. Injury, Mortality, and Fatality Rate by Mechanisms of Injury, 1996

No. ofinjuries

No. ofdeaths

Injury rateper 100,000

Death rateper 100,000

Fatality rate(%)

Traffic accidents 6,467 900 69 10 13.9Assaults 5,120 1,308 55 14 25.5Falls 1,274 141 14 2 11.1Self-inflicted* 539 513 6 5 95.2Other/unknown 665 32 7 0.3 4.8Total 14,065 2,894 150 31 20.6

*Excludes poisoning, drowning, burns.

374 Demetriades et al Epidemiology of Trauma and Trauma Deaths J Am Coll Surg

dead at the scene or were certified dead at nontraumahospitals and were taken to the Coroner’s Depart-ment. Including this group of victims, the total num-ber of major trauma patients for this period was14,065.

The most common cause of injury was trafficaccidents, which were responsible for 45.7% of allcases. Assaults followed closely with 36.2% of allcases. Overall, 2,895 victims of trauma died (mortal-ity 20.6%). Homicides were the leading cause ofdeath and were responsible for 45.3% of all traumadeaths; traffic accidents were next with 31.9% of alldeaths. Table 3 shows the injury and mortality ratesper 100,000 population and the fatality rate accord-ing to mechanism of injury.

Firearms were responsible for 2,802 majortrauma admissions to trauma centers and another1,097 deaths that occurred at the scene or at non-trauma hospitals, for a total of 3,899 cases or 41.7cases per 100,000 population. These figures includeassaults, suicides, and accidental shootings. Of the1,306 homicides, firearms were responsible for 1,184(90.6%). Of the 512 suicides, firearms were involvedin 429 (83.6%). Drowning and poisonings were notincluded in the present study.

The race-specific injury and mortality rates per100,000 persons is shown in Table 4. The African-American population with an injury rate of 300.4and death rate of 56.4 per 100,000 was at a muchhigher risk of injury or traumatic death than were therest of the population groups. Asians had the lowestrisk with 62.7 injuries and 11.6 deaths per 100,000.Table 5 shows the age, gender, and race-specific mor-tality from all mechanisms of injury. Overall, maleswere about 4.5 times more likely to die of traumaticinjuries than were females (crude relative risk 4.41,95% CI 4.02 to 4.84, p , 0.001; adjusted relativerisk 4.57, 95% CI 4.15 to 5.02, p , 0.0001). Thisdifference applied across all races, although it wasmore prominent in Hispanics. The adjusted relativerisk was 6.09 (95% CI 5.17, 7.18) for Hispanics,

Table 4. Race-Specific Injury and Mortality Rates per100,000 Persons in Los Angeles County

1994Population

estimate

Injuriesper

100,000

Traumadeaths per100,000

Caucasian 3,374,246 100.2 26.3Hispanic 3,736,866 166.9 33.5African-American 1,062,408 300.4 56.4Asian/Islander 1,143,076 62.7 11.6Total* 9,373,955 151.4 30.9

*Includes other ethnicity.

Table 5. All Mechanisms of Injury: Age, Gender, and Race-Specific Mortality Rates per 100,000 Persons

< 15 y 15–34 y 35–54 y 55–74 y Total

Caucasian male 4.8 42.8 41.9 52.1 40.1Caucasian female 2.7 11.0 12.4 17.9 12.9Hispanic male 8.8 95.7 52.7 51.4 56.6Hispanic female 5.7 10.6 8.8 13.3 9.3African-American male 7.4 182.5 100.8 71.4 98.3African-American female 7.6 26.1 21.6 12.7 18.5Asian male 1.5 20.3 12.7 35.5 17.0Asian female 0.0 5.1 3.4 18.2 6.6Total male 6.8 79.9 48.0 52.6 50.5Total female 4.6 12.0 11.2 16.2 11.4

Table 6. Race and Age-Specific Adjusted Relative Mortality Risk–All Mechanisms of Injury

RaceAll ages

RR (95% CI)< 15 y

RR (95% CI)15–34 y

RR (95% CI)35–54 y

RR (95% CI)55–74 y

RR (95% CI)

Caucasian/non-Caucasian 0.70 (0.64, 0.76) 0.60 (0.37, 0.97) 0.49 (0.43, 0.57) 0.89 (0.76, 1.03) 1.08 (0.88, 1.32)p , 0.0001 p 5 0.04 p , 0.0001 p 5 0.12 p 5 0.50

Hispanic/non-Hispanic 1.27 (1.17, 1.37) 1.85 (1.28, 2.67) 1.42 (1.28, 1.51) 1.07 (0.91, 1.24) 0.90 (0.70, 1.15)p , 0.0001 p 5 0.001 p , 0.0001 p 5 0.44 p 5 0.43

African-American/non-African-American 2.08 (1.90, 2.28) 1.38 (0.86, 2.22) 2.51 (2.23, 2.83) 2.27 (1.91, 2.70) 0.47 (0.23, 0.95)

p , 0.0001 p 5 0.23 p , 0.0001 p , 0.0001 p 5 0.04Asian/non-Asian 0.35 (0.29, 0.41) 0.12 (0.03, 0.50) 0.24 (0.18, 0.32) 0.24 (0.16, 0.35) 0.77 (0.50, 1.08)

p , 0.0001 p , 0.0008 p , 0.0001 p , 0.0001 p 5 0.15

RR (95% CI) 5 adjusted relative risk, 95% confidence interval.

375Vol. 187, No. 4, October 1998 Demetriades et al Epidemiology of Trauma and Trauma Deaths

5.37 (95% CI 4.34, 6.65) for African-Americans,3.30 (95% CI 2.83, 3.85) for Caucasians, and 2.87(95% CI 1.95, 4.16) for Asians.

Table 6 shows the adjusted relative mortality riskof traumatic death according to race and age. Over-all, Caucasians and Asians had a significantly lowerrisk of traumatic death than other race groups. Themortality rate per 100,000 population according torace and mechanism is shown in Figure 1.

The homicide rate per 100,000 population was40.4 for African-American, 18.7 for Hispanics, 4.0for Caucasians, and 3.4 for Asians. Figure 2 showsthe homicide rate per 100,000 population accordingto race and gender. Overall, males were 8.3 times

more likely to be victims of homicide than were fe-males (25.0 versus 3.0 per 100,000). African-American males were about 12 times and Hispanicmales about 5.5 times more likely to die of homicidethan were Caucasian or Asian males. African-American females were at a significantly higher riskof homicide than were females in other populationgroups (Table 7). Figure 3 shows the firearm-relatedhomicide rate per 100,000 population according torace. The people aged 15 to 34 years were at very highrisk of becoming homicide victims in all race groups.In African-American males in this age group, thehomicide rate was 164.2, in Hispanic males 67.1, inCaucasian males 11.2, and in Asian males 8.9 per

Figure 1. Distribution of deaths per 100,000 according to race and mechanism.

Figure 2. Homicides per 100,000 persons according to race and gender.


Figure 3. Firearm-related homicides per 100,000 according to race.

Figure 4. Penetrating homicides per 100,000 according to race and gender, ages 15 to 34 y. GSW, gunshot wound.

Table 7. Homicides by Penetrating Trauma: Age, Gender, and Race-Specific Mortality Rate per 100,000 Persons

< 15 y 15–34 y 35–54 y 55–74 y All ages

Caucasian male 0.7 11.2 6.5 5.1 6.4Caucasian female 0.0 2.0 2.2 1.5 1.6Hispanic male 3.3 67.1 25.4 8.0 34.1Hispanic female 1.0 4.0 3.3 0.7 2.6African-American male 2.2 164.2 60.6 16.1 73.3African-American female 2.3 19.4 11.1 4.2 10.6Asian male 0.0 8.9 5.7 11.2 6.0Asian female 0.0 1.5 1.1 1.3 1.0Total male 2.2 53.6 18.4 7.6 25.0Total female 0.8 5.0 3.5 1.6 3.0


100,000 population (Fig. 4). The vast majority ofthese homicides were committed with a firearm.African-American females in this age group had asignificantly higher homicide rate than did females inthe other race groups, but significantly lower thanAfrican-American males in the same age group (Ta-ble 7).

There were 921 traffic-related deaths (594 vehi-cle occupants and 327 pedestrians), representing31.9% of all trauma deaths in 1996.The overall mor-tality per 100,000 persons was 9.6. The mortality per100,000 population according to race is shown inFigure 1. Figure 5 shows the mortality according torace per 100,000 from traffic accidents. Table 8

shows the age, gender, and race specific mortality per100,000. The risk of traffic-related death increasessignificantly after the age of 55 years, in both malesand females. The highest risk groups were African-American or Hispanic males over 55 years of age(Table 8). Figures 6, 7, and 8 show the mortality forpassengers and pedestrians, according to race, gen-der, and age.

Pedestrian deaths were more common inAfrican-Americans and Hispanics than in Cauca-sians or Asians. Table 9 shows the age, gender, andrace-specific mortality from pedestrian accidents.

There were 513 suicides, excluding poisonings(17.7 of all trauma deaths). Firearms were used in

Figure 5. Mortality because of traffic accidents per 100,000 according to mechanism and race..

Figure 6. Automobile deaths per 100,000 persons according to race and gender.


429 cases (83.6%), jumping from a height in 47(9.2%), knives in 23 (4.5%), and other mechanismsin 14 (2.7%). Caucasians had the highest suicide rateper 100,000 population and Asians the lowest (Fig.1). Males were at a significantly higher risk of com-mitting suicide than were females in all age groupsover 15 years of age. Caucasian males, over 65 yearsof age, were at a higher risk of suicide than any otherrace or age group (Fig. 9). Table 10 and Figure 10show the age, gender, and race-specific suicide rateper 100,000. Suicides by fall from heights may beunderpresented because many undocumented casesmay have been classified under unintentional falls.

Figure 7. Pedestrian deaths per 100,000 according to race and gender.

Figure 8. Deaths per 100,000, motor vehicle occupants and pedestrians by age. MVA, motor vehicle accident.

Table 8. Traffic Accidents: Age, Gender, andRace-Specific Mortality Rate per 100,000 Persons

< 15y

15–34y

35–54y

55–74y Total

Caucasian male 2.9 14.5 15.7 16.5 13.9Caucasian female 1.9 4.9 5.1 10.6 6.5Hispanic male 4.6 16.8 16.7 27.5 13.9Hispanic female 4.1 5.8 4.5 9.8 5.8African-American

male 5.2 11.2 19.0 33.9 14.7African-American

female 5.3 5.5 7.8 5.7 6.1Asian male 0.8 8.3 3.2 19.4 7.9Asian female 0.0 2.0 2.3 13.0 4.2Total male 3.8 14.4 14.8 21.5 13.3Total female 3.3 5.1 4.9 10.1 5.9


There were 141 deaths from falls from a height,excluding confirmed suicides (1.5 deaths per100,000). The death rate according to race groups isshown in Figure 2. Seventy-three percent of the vic-tims were male and 27% were female.The age groupsover 50 years of age accounted for 54.6% of all deathsfrom falls.

DISCUSSIONAlthough trauma has been recognized as a major ep-idemic in the United States, very few studies haveexamined the injury and fatality rates and epidemio-logical patterns in a defined geopolitical area.2,3 Thelarge size of Los Angeles County, its demographiccomplexities and the magnitude of the trauma prob-lem make such studies important to get an accurate

picture of the severity and nature of the trauma prob-lem and to plan new prevention strategies.

Severe trauma affected 151.4 people and resultedin 30.9 deaths per 100,000 population in the countyof Los Angeles. Although traffic accidents were theleading cause of severe injury, homicides were by farthe leading cause of traumatic deaths. Homicideswere responsible for 45.3% and traffic accidents for31.9% of trauma deaths. Despite the reduction ofthe homicide rate from a high 23.7 per 100,000 in1980 and 22.1 per 100,000 in 1990 to 14.0 per100,000 in 1996 (Fig. 11), it is still significantlyhigher than the national average of 8.4 or the Cali-fornia average of 11.3 in 1995. The number of ho-micides in the last 35 years kept increasing from 296in 1961 to a peak of 2,116 in 1992. The homicide

Figure 9. Suicides with penetrating trauma per 100,000 persons according to race and gender.

Table 9. Pedestrian Accidents: Age, Gender, andRace-Specific Mortality Rate per 100,000 Persons

<15y

15–34y

35–54y

55–74y Total




Table 10. Suicides:* Age, Gender, and Race-SpecificMortality Rate per 100,000 Persons

< 15y

15–34y

35–54y

55–74y Total




*Excluding poisoning, drownings, burns.


figures for 1996 are the lowest in the last 16 years(Fig. 12). It is difficult to identify any specific inter-ventions to account for these changes. Improvedeconomy, better policing methods, stricter penalties,and more efficient prevention programs could allhave contributed. We hope to evaluate the possiblerole of these factors in a future study.

The African-American population, at a homiciderate of 40.4 per 100,000, is at a much higher riskthan are other population groups (2.5 times higherthan Hispanics, 11.2 times higher than Caucasians,and 12.7 times higher than Asians). A similar patternin homicides in children over 14 years of age in Los

Angeles was reported in a previous study.4 Homicidesin the age group 15 to 34 years is a major epidemic inAfrican-American males, with 164.2 killings by pen-etrating trauma per 100,000 population. This is farabove the targeted maximum of 72.4 per 100,000envisioned by the “Year 2000 National Health Ob-jectives.” Hispanics in the same age group followwith 67.1 homicides per 100,000, which is also wellabove the maximum of 33.0 per 100,000 envisionedby the “Year 2000 National Health Objectives” (Ta-ble 11). The overall firearm-related homicide rateamong African-Americans was 40.9 per 100,000,which is well above the Healthy California 2000 tar-

Figure 10. Suicides per 100,000 persons according to age.

Figure 11. Annual homicide deaths per 100,000 persons, 1980 to 1996.


get (no more than 30.0 firearm-related deaths per100,000 population among African-Americans).5

The role of firearms needs to be reexamined evenmore intensively than it has in the past few years.Firearms were used in 90.6% of homicides and83.6% of suicides. In 1993, firearms accounted for75% of homicides in California.6 Firearm assault vic-tims had a high probability of dying at the scene.Five-hundred and nine (43.8%) of the 1,163 firearmhomicides were pronounced dead at the scene andwere transported to the Coroner’s Department.

Analysis of the traffic-related deaths showedsome interesting patterns. Males had a significantlyhigher passenger death rate than did females, in allrace groups. In pedestrians, the overall mortality ratewas significantly higher in males, but in Asians therewas no difference. The age group over 55 years of agewas at a significantly higher risk of dying from trafficaccidents, especially pedestrian accidents, than wereyounger age groups. The reasons for this observationneed to be investigated and appropriate measures

taken. We analyzed trauma epidemiology only for1996, and we cannot make any comparisons withprevious years. The role of alcohol, safety belt use,and airbags in survival has not been studied. Theseissues merit a separate study, and we hope to performsuch a study in the near future.

The suicide rates are grossly underestimated inthe present study because poisoning, overdosing, anddrowning are not included. Furthermore, many sui-cides by falls from heights are not included because oflack of documentation. Firearm-related suicides ac-counted for 429 cases (4.6 per 100,000) and the ratewas much higher for Caucasians (9.8 per 100,000).Caucasian males over 65 years of age were at thehighest risk of suicide by penetrating trauma, with29.5 deaths per 100,000.

In summary, we investigated the epidemiology oftrauma in a large and demographically diverse met-ropolitan area.Trauma remains a major cause of mor-tality and hospitalization. Intentional trauma is theleading cause of traumatic deaths, and firearms play a

Figure 12. Number of homicides per year, 1961 to 1996.

Table 11. Healthy California “Year 2000 National Health Objectives” and Current Figures in Los AngelesCounty: Violent and Abusive Behavior

ObjectivesYear 2000 aims

(deaths per 100,000)Los Angeles County figures

(deaths per 100,000)

Overall homicides ,7.2 14.0Homicides in African-American males 15–34 years ,72.4 164.2Homicides in Hispanic males 15–34 years ,33.0 67.1Homicides in African-American females 15–34 years ,16.0 19.4Overall firearm-related deaths ,11.6 17.2


major role. Although homicides decreased signifi-cantly, they still remain above the national or Cali-fornia figures, and far exceed the objectives of “Year2000 National Health Objectives.” Certain race andage groups are at an exceedingly high risk for homi-cide deaths. Epidemiological patterns and trendswith other mechanisms such as traffic accidents andsuicides have also been identified and discussed.

Acknowledgment: The authors would like to ex-press their appreciation to Mr. J. Muto from the Cor-oner’s Department for his help and to Mrs. D. Mc-Mahon for preparing the manuscript.

References1. U.S. Bureau of the Census: Estimates of the Population of Counties

by Age, Sex, Race, and Hispanic Origin: 1990 to 1994. PE-47,PE-48, PPL-49, PPL-50, 1996.

2. Coben JH, Dearwater SR, Forjuoh SN, Dixon BW. A population-based study of fatal and non-fatal-firearm-related injuries. AcadEmerg Med 1997;4:248–225.

3. Bretsky PM, Blanc DC, Phelps S, et al. Epidemiology of firearmmortality and injury estimates: State of Connecticut, 1988–1993.Ann Emerg Med 1996;28:176–182.

4. Sorenson SB, Richardson BA, Peterson BA. Race/ethnicity patternsin the homicide of children in Los Angeles, 1980 through 1989.Am J Public Health 1993;83:725–727.

5. California Department of Health Services, Year 2000 NationalHealth Objectives, Priority Area 7, Violent and Abusive Behavior.

6. Chu LD, Sorenson SB. Trends in California homicide, 1970–1993.West J Med 1996;165:119–125.


epidemiology of major trauma and trauma deaths in los angeles county

Documents