disaster epidemiology lessons from bam earthquake dec 26, 2003 iran part 5: the methodological...
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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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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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