Injury EpidemiologyInjury Epidemiology

An Introduction

readings

Thomas Songer, PhDUniversity of Pittsburgh

What are Injuries?

Causes of Injuries

• Abnormal Energy Transfer–Mechanical Energy (moving objects)–Thermal–Electric–Chemical

–Radiation

Energy Transfer and Injuries

• Penetrating• Non-Penetrating• Compression• Burn

Percentage of all Injury Deaths Caused by Mechanical Energy, 1986

31%

22%

8%

13%

26%

Motor VehicleFirearmsFallsOther Mech. E.Not Mechanical

United StatesBaker, 1992

• Motor Vehicle Crashes• Homicide• Suicide• Sports and Recreation• Drownings• Poisonings• Falls• Occupational Injuries• Burns• Asphyxiation

Where does epidemiology tie in?

Leading Causes of Death in Developed Regions, 1990

(Based on number of deaths)1. Ischemic Heart Disease2. Cerebrovascular Disease3. Lung Cancer4. Lower Respiratory Infections5. COPD6. Colon and Rectum Cancer7. Stomach Cancer8. Road Traffic Accidents9. Self-Inflicted Injuries

10. Diabetes Mellitus GlobalBurden of Disease

Leading Causes of Death Worldwide, 2000(Based on number of global deaths)

1. Ischemic Heart Disease2. Cerebrovascular Disease3. Lower Respiratory Infections4. HIV/AIDS5. COPD

6. Perinatal Conditions7. Diarrhoeal Diseases8. Tuberculosis9. Road Traffic Injuries10. Lung Cancers

WHR 2001

Leading Causes of Death in the United States, 1992

(Based on number of deaths)1. Heart Disease2. Malignant Neoplasms3. Cerebrovascular Disease4. COPD5. Accidents/Injuries6. Pneumonia7. Diabetes mellitus8. HIV infection9. Suicide

10. Homicide

Leading Causes of Death, USA, 2000(number of deaths)

1. Heart Disease2. Neoplasms3. Cerebrovascular Disease

4. Chronic Pulmonary Disease5. Accidents/Injuries6. Diabetes mellitus

7. Influenza and pneumonia8. Alzheimer’s Disease

9. Nephritis, nephrotic syndrome10. Septicemia

Years of Life Lost Prior to Age 70, 1987

0

1000

2000

3000

4000

5000

Injury Cancer CHD AIDS Stroke

Baker, 1992

Motor Vehicle Crash Death Rates among Males by Country, 1980

0

20

40

60

80

Rat

e pe

r 10

0,00

0 po

p.

USA France Japan GER UK

Age group

Alcohol Involved Crashes by Time of Day

1991 GES

Number of Crashes

0

50

100

150

Num

ber

(tho

usan

ds)

6-10 10-2 2-6 6-10 10-2 2-6Afternoon Early Morning

Do injury patterns differ around the

world?

Mortality Rates by Cause of Death

1

10

100

1000

India China DevelopingCountries

OECDCountries

Comm. NCD Injury

deaths per 100,000 population

Source: World Bank,Investing in Health, 1993

Injury Mortality Rates of U.S. Male Travelers by Region, 1975,1984

0

100

200

300

400

25-34 35-44 45-54 55-64 65+

rate

per

100

,000

Developing Developed

Age Group Hargarten, 1991

Crude Injury Mortality Rates in Males by Level of Economic Development

0

20

40

60

80

100

120

140

SriLan Egypt Thai Chile Mex Arg Swe USA

pe

r 1

00

,00

0 p

op

ula

tion

GNP $ 400 760 810 1320 1973 2350 13,160 17,980

Changes in Mortality in Mexico

0

20

40

60

80

100

120

1950 1955 1960 1965 1970 1975 1980

Rat

e p

er 1

00,0

00 p

op.

Injuries Malaria Heart Dis. Diabetes

Frenk 1991

Adjusted Male Mortality from Homicide: Selected countries

0

15

30

45

60

75

Japan Switz Israel USA - white

USA- AA

rate per 100,000 pop.

Fra Can Chile USSR

1989-1991

Injury Control

DefinitionsDefinitions

• Reducing the incidence of disease• Reducing the prevalence of disease

• Ongoing programs aimed at reducing the incidence and/or prevalence of disease

PreventionPrevention

ControlControl

Last, Dictionary of Epidemiology

A Model of Injury Control

Monitorincidence

Identifyrisk factors

Intervene Evaluate

Identifymorbiditymortality

cost

socialgenetic

environmentalhealth care

Advances in the Epidemiology of Injuries as a Basis for Public PolicyAdvances in the Epidemiology of

Injuries as a Basis for Public Policy

William Haddon, MD, MPHWilliam Haddon, MD, MPH

Public Health Reports 1980; 95(5):411-421

HostEnvironment

Agent

Human

Environment

Vehicle

Injuries and the Epidemiology Triad

PhysicalSocial

Risk factors for motor vehicle crashes

Human

Environmental

Vehicular

FailureDesignSpeed

AgeGenderExperience

AlcoholFatigue

Road ConditionsTrafficWeather

The Haddon Matrixuse for planning, resource allocation, strategy identification

Human Vehicle Environment

Pre-event

Event

Post-event

The Haddon Matrix

Human Vehicle Environment

Pre-event

Event

Post-event

alcohol

no seatbelt

no air bag

night, rain

tree too close to road

slow emergencyresponse

Crash Injury Prevention Strategies for the International Traveler

Traveler Vehicle Environment

Pre-event

Event

Post-event

Avoidalcohol

use seatbelts

Avoid nightdriving

Know localmedical system

Choosesafe cars

Ten Methods for Limiting Physical Energy Transfer

1. Prevent the development of energy form

2. Reduce the amount of energy

3. Prevent the energy release

4. Alter the rate of energy release from it’s source or it’s spatial distribution

5. Separate structures from the energy release by space or time

Methods to limit energy transfer...

6. Place a barrier between the released energy and susceptible structures

7. Modify surfaces that can be impacted

8.Strengthen structures susceptible to damage from energy transfer

9. Prevent the extension of existing damage

10. Carry out intermediate and long-term repair and rehabilitation