Session 5, Part 1
Epidemiology Applications:
Disaster and Environmental Epidemiology
Learning Objectives
Session 5, Part 1
• Identify epidemiology methods that can be
used regardless of epidemiologic specialty
• Describe the Community Assessment for
Public Health Emergency Response
(CASPER) process
• List 4 functions of environmental
epidemiology
Overview
Session 5, Part 1
• Framework for epidemiology
specialties
• Disaster epidemiology methods
• Environmental epidemiology
Framework for Epidemiologic
Applications
Reminder:
What is Epidemiology?
“Study of the distribution and determinants of
health-related states or events in specified
populations, and the application of this study to
the control of health problems.”
--From A Dictionary of Epidemiology, 3rd ed.
• Study risk associated with exposures
• Identify and control epidemics
• Monitor population rates of disease and exposure
*Last JM, ed
Goals of Epidemiology in a
Health Department
• Collect and use high quality data
• Understand limitations of data
• Work to improve data collection and quality
• Use analytic results for planning and evaluation
of disease and injury prevention programs
• Contribute new information for the
understanding and prevention of disease and
injury
Methods for Accomplishing
Epidemiologic Goals
• Acute response
• Ongoing surveillance
• Epidemiologic analysis
• Dissemination of results
• Advocacy and enforcement
Disaster Epidemiology
Disaster Epidemiology-Defined
• CDC defines as: The use of epidemiology
to assess the short- and long-term
adverse health effects of disasters and to
predict consequences of future disasters
• Unites various topic areas of
epidemiology, e.g. communicable disease,
chronic disease, injury, mental health, etc.
Disaster Epidemiology
Methodologies
• Rapid assessments using CASPER methods
• GIS and GPS Technology
• Examples of rapid needs assessment/
CASPER in disaster and non-disaster
settings
– Example 1: PHRST 5 Tool
– Example 2: Hurricane Irene in NC, 2011
– Example 3: Community Health Assessments
– Example 4: KI distribution survey in NC, 2010
Definition of CASPER
• Format:
– Face-to-face survey with
people living in affected area
• Target audience:
– Decision-makers
• Benefits
– Quick and low-cost
– Accurate and useful
information
Hurricane Hugo, near Charleston, SC, September, 1989.
Source: CDC Public Health Image Library
Purpose of a CASPER
Determine type and
magnitude of needs to plan
and implement relief efforts
What CASPERs are NOT
• Do not deliver food, medicine, medical
services or other resources to the affected
area
• Do not provide direct services to residents
such as cleanup or home repair
CASPER
Sample Selection
• Select a sample area
– Storm path, damage reports, service areas
• Randomly select 30 population weighted
geographic clusters in sample area
• Randomly select 7 households within each
geographic cluster
• 210 total surveys, 10 survey teams
GIS as a CASPER Tool
• Tools for storing, manipulating, analyzing and
displaying spatial data
• Used to construct maps that communicate
spatial data
– Raster-based: Data and image stored in a
regularized grid made of pixels [Satellite]
– Vector-based: Data and image stored separately in
map layers (points, lines, polygons) – [EpiInfo’s Epi
Map, ArcMap]
• Map layers use x-y coordinate system based on
latitude and longitude
GPS (Global
Positioning System)
Field Data Collection
GIS Software
Field
Team 1
Field
Team 2
Field
Team 3
Field
Team 4
Field
Team 5
Field data collection using handheld computers equipped with GPS, GIS
software and data collection forms.
ARCPad GIS Software on
Handheld Computer
ArcPad
Routing
Function
Customized Form
ArcPad
programmed to
automatically insert
cluster # in
database for
complex samples
analysis
ArcPad form
programmed to
automatically
insert census
block group
population in
survey
Assigns a
unique case ID
or incident #
Creating Forms in ArcPad Studio
Example 1:
PHRST Tool for CASPER
PHRST
Toolbar
created for
ArcMap
Stage 1
Stage 2
Site selection toolkit freely available from UNC (cphp.sph.unc.edu/sharpgis/)
Example 2:
Hurricane Irene, 2011
Hurricane Irene
CASPER Results
• 205 interviews
– 27.8% of respondents
evacuated
– Only 35% of county
residents knew an
evacuation order had
been issued
– Evacuation rates highest
among those living in 100
year flood plain
Example 3:
Community Health Assessments
• Identify factors that affect the
health of the population
• Determine the availability of
resources to meet identified
needs
• Collaborate with community
leaders, public health,
hospitals, private practitioners,
academic partners
Community Health Assessments
• CHA Report
– Gives information about
the health of the
community
– Describes community
capacity to improve the
lives of residents
• CASPER
– Reduces the number of
surveys needed
– Allows for efficient and
more accurate data
collection
Example 4:
KI Distribution Survey, 2010
• Very low household coverage
rates (<5%)
• Knowledge of KI positively
correlated with:
–
–
–
–
Age
Length of residence,
EPZ awareness and
White race
• Low levels of concern about
nuclear accident
Disaster Epidemiology Recap…
• CASPERs fulfill vital public health function
• Use of incident command system (ICS) is vital to
rapid deployment of resources
• Handheld computers, GIS and GPS adds value
to field data collection in rapid needs
assessments
–
–
–
–
Eliminates double data entry
Provides routing and direction-finding for field teams
Improved randomization through GIS
Ability to quickly analyze and map data
Environmental Epidemiology
Mission of Environmental
Epidemiology
• Reduce incidence and severity of disease
and adverse health conditions due to
environmental exposures
• Identify populations at risk of
environmental exposures
• Understand and prevent disease and
adverse health conditions
Environmental Epidemiology
Programs
May exist alone or in combination with other
epidemiologic disciplines:
• Injury
• Chronic
• Occupational
• Zoonotic
• Toxicology
Core Functions of
Environmental Epidemiology
• Conduct site-specific assessments
• Conduct health, environmental, and
biological surveillance
• Respond to community concerns
• Conduct health professional and
community education
Technical Assistance and
Partner Relationships
• Cooperation and coordination with
EPA and local health departments
• State departments of Environment
/ Environmental Management /
Natural Resources
– Chemical release
– Planning and public
communications
– Human-environment interaction
• State-based hazard and
pollution programs
Preparedness
• Technical support for response planning
and implementation
• Education and outreach
– High-risk populations
– First responders
• Identify vulnerable populations
• Chemical terrorism fact sheets
Other Programs in
Environmental Epidemiology
• Toxins, occupational exposures
– Blood lead
– Asbestosis
– Silicosis
•
•
•
•
Pesticides
Air pollution
Hazardous waste
Special studies
Summary
• Epidemiology methods can have many
applications
• Disaster epidemiology to assess disaster
impacts, guide response and prepare for
future disasters
• Environmental epidemiology monitors
populations for health repercussions of
environmental contamination
References
•
•
•
•
•
•
Last JM. A Dictionary of Epidemiology. 3rd ed. New York, NY: Oxford
University Press; 1995.
Law D. Introduction to Geographic Information Systems. Methods in Field
Epidemiology Lecture Series. Department of Epidemiology, University of
North Carolina at Chapel Hill School of Public Health; 2005.
Malilay J, Flanders WD, Brogan D. A modified cluster-sampling method for
post-disaster rapid assessment of needs. Bull World Health
Organ. 1996;74(4):399-405.
MacDonald PDM. Methods in Field Epidemiology. Burlington, Mass: Jones
& Bartlett Learning; 2012.
Beitsch LM, Brooks RG, Grigg M, Menachemi N. Structure and Functions of
State Public Health Agencies. Am J Public Health. 2006;96(1):167-172.
Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1470433/.
Accessed December 29, 2011.
Health Studies Branch - Preparedness and Response for Public Health
Disasters. [Web page.] National Center for Environmental Health, Centers
for Disease Control and Prevention. Available at:
http://www.cdc.gov/nceh/hsb/disaster/. Accessed March 1, 2012.