Disaster Epidemiology Lessons From Bam

Earthquake Dec 26, 2003 Iran

Part 5: The methodological lessons from Bam earthquake

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Ali Ardalan MD, MPH, PhD student in Epidemiology

Learning objectives:

To understand some applications and limitations of epidemiologic studies in earthquakes

To understand the application and methodology of Rapid Health Assessment in Bam.

To learn about the application of Geographic- based sampling method in Bam.

To learn about important points of ethical issues of research in disasters

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Challenges and problems facing Epidemiologists following the disasters Political environment

Changing social conditions and demographics

Difficulty in applying standard epidemiologic

techniques in the context of great destruction

Lack of time for organizing epidemiologic

investigation

Absence of well defined population counts

Lack of active collaboration between scientists from different disciplines 3

Rapid Health Assessment after

the earthquake

Objectives:

To identify, define and prioritize potential impacts in disaster

situations

To help mobilize resources and

direct them to where they are most

needed.

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Rapid Health Assessment The principles of methodology:

Simple consensus-based qualitative assessment process

Not replace the quantitative studies, but fills a gap until such studies are appropriate.

Can be used from the time disaster happens till some month later, or for any major stage-change in an extended crisis.

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Rapid Health Assessment Source of information:

Direct observation of the field

Reviewing of the pre-disaster records

Reviewing of community profiles in the news and on the Internet, and diverse reports.

Interviewing with local and national authorities

Interviewing with affected people 6

Rapid Health Assessment in the

Bam Earthquake

As part of a joint mission of the

World Health organization (WHO) with the

Iranian Ministry of Health (MoH), a rapid

assessment was conducted on the health

status of the affected population and health

activities in Bam on Dec 27, 2003.

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Survey Methodology-Phase 1:

Feasibility study

Interviews with local disaster

managersDirect observation

of the field

Assessment of population-based

design

requirements8

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10

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Ethical issues of population-based research in disasters

The most important point,

People must be informed that the interviews are unrelated to providing

information for personal service deliveries to deal with their needs.

Verbal consent

Confidentiality of individual information

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Geographic-based sampling design in disasters

A very useful tool in Bam,

because of lack of a sampling

frame of residential tents.

Geographic-based sampling plan

Cross-road

Square

Selected start point

Geographic zone

Section 1

Section 3

Section 2

Main street

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500 m

Minor street, Alley

Movement direction

Tent

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Cross-road

Square

Selected start point

Main street

Geographic-based sampling plan

500 m

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Minor street, Alley

Movement direction

Tent

Cross-road

Square

Selected start point

Main street

Geographic-based sampling plan

Cross-road

Square as selected

start point

Main street

Minor street, Alley

Tent

Movement direction

500 m

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Geographic-based sampling plan

Limitation of cross-sectional studies in post-disaster period of Bam

earthquake

Potential selection bias in determining the risk factors of

mortality and injuries and also their

incidence estimations

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Population movement After the earthquake

Zones

Earthquake-stricken

area

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77%

15%

7%1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

Bricks,concrete,

steel

Clay andmud bricks

Mud bricksbearing

walls, withsteel roof

Othermodern

style20

The main construction materials of earthquake-stricken population houses based on a cross-sectional study on 19th and 20th days of post-disaster period in Bam

A consequence of cross-sectional studies in post-disaster period of Bam

Total death: 40 % of

population

Death by

cross-sectional

study

18 %

Selection

bias

- 45 %

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Conclusion:Considering the limitations of cross-sectional and case-control studies, it seems a retrospective cohort approach, for instance, based on before-quake list of governmental employees, would be decreases the aforementioned problem.

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