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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 sampling Hurricane Andrew Street map of Homestead-Florida City with superimposed sampling frame of quartermile square clusters used during rapid needs assessment after Hurricane Andrew. (6) Cluster Sampling Hurricane 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 clustersampling 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.