Epidemiology Applications: Disaster and Environmental Epidemiology

Session 5, Part 1

Learning ObjectivesSession 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

OverviewSession 5, Part 1

• Framework for epidemiology specialties

• Disaster epidemiology methods

• Environmental epidemiology

Framework for Epidemiologic Applications

Reminder: What is Epidemiology?

• Study risk associated with exposures• Identify and control epidemics• Monitor population rates of disease and exposure

*Last JM, ed

“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.

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

CASPERSample 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 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.

Field Data Collection

GIS Software

ArcPad Routing Function

ARCPad GIS Software on Handheld Computer

Assigns a unique case ID or incident #

ArcPad form programmed to automatically insert census block group population in survey

ArcPad programmed to automatically insert cluster # in database for complex samples analysis

Customized Form

Creating Forms in ArcPad Studio

Example 1: PHRST Tool for CASPER

PHRST Toolbar

created for ArcMap

Site selection toolkit freely available from UNC (cphp.sph.unc.edu/sharpgis/)

Stage 1

Stage 2

Example 2: Hurricane Irene, 2011

Hurricane IreneCASPER 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

• 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

Community Health Assessments

• 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

Example 4: KI Distribution Survey, 2010

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.