Rapid Needs Assessments and GIS. Goals Describe the uses of rapid needs assessments in post-disaster...

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Rapid Needs Assessments and GIS

Transcript of Rapid Needs Assessments and GIS. Goals Describe the uses of rapid needs assessments in post-disaster...

Rapid Needs Assessments and GIS

Goals Describe the uses of rapid needs

assessments in post-disaster settings Understand the sampling

methodology used with rapid needs assessments

Discuss how geographic information systems can be used with rapid needs assessment

Provide examples of other types of rapid surveys in public health

Rapid Needs Assessments Provide information about

community needs in disaster aftermath (1)

Provide information to match emergency needs with available resources

When used with rapid mobilization of resources can reduce adverse public health consequences (2)

Rapid Needs Assessments

Rapid needs assessments can: establish the extent/possible evolution

of an emergency measure the present/potential public

health impact determine existing response capacity

and identify any additional immediate needs

inform priority response actions (3)

Methodology Accurate sampling is important World Health Organization Expanded

Programme on Immunization (EPI) cluster sampling methodology(4)

EPI method is a 2-stage cluster sample 1st stage - 30 clusters (geographical areas)

selected 2nd stage - 7 points (housing units) within

each cluster

EPI Method

Easy to implement in the field Requires few resources Yields reasonably valid and precise

estimates

Two-stage cluster sampling Has been adapted over the years for

various purposes. (6) 1960s – tool for local health departments to

assess community coverage of immunization, service coverage

1970’s – modified and used with smallpox eradication in West Africa

1980s – adapted by WHO for EPI program 1990s – revised to include community

volunteers, incorporate census data and random sampling of second-stage participants. Adapted by CDC for rapid needs assessments after disasters

EPI Cluster Sampling Example

Hurricane Andrew, Florida, 1992 EPI cluster-sampling method used Clusters defined in grid of quarter-

mile square areas using street maps of 2 communities hit hardest by hurricane

Cluster samplingHurricane Andrew Street map of

Homestead-Florida City with super-imposed sampling frame of quarter-mile square clusters used during rapid needs assessment after Hurricane Andrew. (6)

Cluster SamplingHurricane Andrew

Survey--interviews conducted at 7 housing units in each of 30 clusters

Separate surveys conducted at 3, 7, and 10 days after hurricane landfall

Surveys used to provide information to public health officials for directing and monitoring relief units (6)

Modified EPI Cluster Sampling 1996, EPI cluster sampling method

modified Added features included the ability

to: Estimate size of overall post-disaster

population Estimate numbers of persons with

specific needs Assess number of damaged/destroyed

housing units

Modified EPI Cluster Sampling Disaster site divided into blocks/clusters First stage, a sample of n clusters (n=30

as in EPI method) such that: Clusters with more housing units are likely to

be included (probability proportional to estimated number of housing units)

Second stage, equal probability of k housing units is chosen (k=30 as in EPI method): Interview conducted at each housing unit

Modified EPI Cluster Sampling Interviewer makes multiple attempts to conduct

an interview at a selected housing unit EPI method—interviewer moves to adjacent housing

unit after single interview attempt If repeated attempts do not result in interview, a “0” is

recorded for that site Allows for collection of more information than

EPI method (housing units are counted, those damaged/destroyed are noted, all persons in selected households are counted)

Data can be used to estimate size of overall disaster population

Modified EPI Cluster Sampling Adopted by CDC

as the standard for conducting rapid needs assessments after disasters

First used in North Carolina after Hurricane Isabel in 2003

Rapid Surveys for Community Assessments Rapid survey method used with post-

disaster needs assessments can be adapted for other community assessments Example: Rapid survey in Hispanic area of Los

Angeles to look at immunization status (9)

Example: North Carolina county health departments conducting community health assessments and assessing population vulnerabilities prior to potential catastrophic events (10)

Geographic Information Systems Geographic information systems (GIS)

can be a useful tool for conducting rapid needs assessments or rapid surveys

GIS can provide a more scientific approach to second stage randomization Random points can be selected and plotted Interviews are conducted with a resident of

the house located nearest to the random point

Reduces potential selection bias by interview teams

Advantages of Using GIS

Using GIS allows use of global positioning system (GPS)-based routing

GPS Aids team in navigation Provides more up-to-date maps Replaces paper maps

Advantages of Using GIS

GIS can replace paper-based surveys with computer-based surveys

GIS software can be uploaded onto handheld computers for field deployment

Computer-based data entry can save time, reduce data entry errors

Summary Rapid needs assessment is an

essential component of disaster relief operations (6)

Rapid needs assessments allow public health officials to quickly identify and prioritize areas of need

Methods used with rapid needs assessment can be extended to other areas of public health

References 1. Surveillance and rapid needs assessment. Centers for

Disease Control and Prevention. Web site. http://www.cdc.gov/nceh/hsb/disaster/surveillance.htm. Accessed April 24, 2008.

2. Lillibridge SR, Noji EK, Burkle FM. Disaster assessment: The emergency health evaluation of a population affected by a disaster. Ann Emerg Med. 1993;22:1715-1720.

3. World Health Organization. Rapid health assessment proocols for emergencies. Geneva, Switzerland: World Health Organization; 1999:1.

4. Frerichs RR. Rapid surveys. Department of Epidemiology, School of Public Health, University of California, Los Angeles Web site. http://www.ph.ucla.edu/epi/rapidsurvey.html. Updated May 26, 2008. Accessed June 4, 2008.

References  5. Lemenshow S, Robinson D. Surveys to measure

programme coverage and impact: A review of the methodology used by the Expanded Programme on Immunization. World Health Stat Q. 1985;38:65-75.

6. Hlady WG, Quenemoen LE, Armenia-Cope RR et al. Use of a modified cluster sampling method to perform rapid needs assessment after Hurricane Andrew. Ann Emerg Med. 1994;23(4):719-725.

7. 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.

8. Centers for Disease Control and Prevention. Rapid community health and needs assessments after Hurricanes Isabel and Charley—North Carolina, 2003—2004. MMWR Morb Mortal Wkly Rep. 2004;53:840-842.

References 1. Frerichs RR, Shaheen MA. Small-community-

based surveys. Annu Rev Public Health. 2001;22:231-247.

2. Horney J, Snider C, Gammons L, Ramsey S. Factors associated with hurricane preparedness: Results of a pre-hurricane assessment. J Natural Dis. 2008;3(2):143-149.