Disaster Epidemiology

CASPER stands for Community Assessment for Public Health Emergency Response. It is an epidemiologic technique conducted in the field. CASPERs are designed to provide public health leaders and emergency managers with household-level information about a community. Compared to other reliable survey techniques, CASPERs are quick, relatively inexpensive, and flexible.

CASPER Overview

CASPERs are a type of rapid needs assessment (RNA). The CDC coined the term CASPER to distinguish this type of RNA from other types used during disaster response. CASPERs and rapid needs assessments (RNAs) have been conducted in Texas communities since 2001. 

CASPERs follow a specific sampling design called two-stage cluster sampling. This type of sampling proceeds through two stages. The first stage allows health departments to determine which sections (clusters) in the community will be sampled. Random sampling is used to select clusters during this first stage. The number of clusters to select is set at 30 by the CASPER sampling design. Certain other criteria must be met to conduct this type of sampling (i.e., set a sampling frame, and follow how clusters are defined).

This first stage of sampling can be conducted by one or a few health department staff. Maps of the selected clusters are usually made to help with the second stage of sampling.

The second stage allows health departments to know which homes to approach (visit) within the selected clusters. Homes are approached (selected for a visit) using a process called systematic random sampling. CASPER teams of 2-3 health department staff are needed to conduct this type of sampling in the field.

CASPER data collection is also conducted by CASPER teams in the field. Teams are assigned clusters (chosen during first stage sampling) and approach homes within their assigned cluster(s) using the systematic random sampling process. When a home is visited, the head of household in the home is asked by a CASPER team member if they consent to an interview. If consent is provided, the head of household answers questions about their household. If consent is not given, CASPER teams continue visiting homes using the systematic random sampling process until the targeted number of households that need to be interviewed is reached. The targeted number is set at 210 per the CASPER methodology and at least 80% of 210 (168) is needed to generate population estimates.

The area where CASPER data collection is conducted is only within the specific sampling frame set for a CASPER. By design, the CASPER data collection process occurs within a short duration of time (usually days). This allows the cross-sectional epidemiologic design of a CASPER to remain intact.

Deaths resulting directly or indirectly from a disaster can serve as an important indicator of a disaster’s severity and impact on the affected population.  The DSHS State Medical Operation Center (SMOC) conducts disaster-related mortality surveillance primarily for common major natural disasters (i.e., hurricanes).

The purpose of disaster-related mortality surveillance is to:

• Identify the number of deaths related to the public health emergency and provide basic demographic information to public health and emergency management officers
• Identify the causes of death related to the disaster to inform public health interventions
• Assess the direct and indirect impact; and
• provide information on disaster-related deaths to inform future planning and mitigation efforts.

Reporting Disaster Deaths 

Disaster-related deaths should only be reported to DSHS when the DSHS State Medical Operation Center (SMOC) conducts disaster mortality surveillance operations.  

Medical certifiers will receive instructions on how to report disaster deaths to DSHS from the SMOC and the Vital Statistics Section (VSS) during a disaster response activation. Medical certifier offices include local medical examiners (if one exists locally), Justice of the Peace offices, and physician certifiers.

Reporting Form

The Disaster-Related Mortality Surveillance Form is completed by Texas medical certifiers when reporting disaster deaths to the SMOC.  Ideally, the information to complete the form should be gathered and the form completed within 24 hours of a disaster death. 

• Disaster-Related Mortality Surveillance Form (PDF)

Medical certifiers also indicate death as disaster-related in the death certificate record. Submitting a disaster-related mortality form does not replace indicating the disaster on the death certificate. Conduct both activities when DSHS asks medical certifiers to begin reporting disaster deaths.  

For questions about how to enter disaster-related information in the death certificate, medical certifier staff can contact the DSHS Vital Statistics Section’s Field Services.

Medical Certifier Resources

The following resources can help medical certifiers recognize direct and indirect disaster-related deaths.

• Death Scene Investigation After Natural Disaster or Other Weather-Related Events - A Toolkit
• A Reference Guide for Certification of Deaths in the Event of a Natural, Human-Induced, or Chemical/Radiological Disaster
• CDC eLearning: Guidance for Certification of Deaths in the Event of a Natural, Human-Induced, or Radiological/Chemical Disaster

Links and Publications

2021 Winter Storm Mortality Surveillance Report 

DSHS’s Disaster Mortality Surveillance Unit completed its 2021 Winter Storm surveillance analysis. This final report includes surveillance methodologies, data sources, circumstances/causes of deaths, decedent demographics, and storm deaths-by-county totals. Centers for Disease Control and Prevention definitions for direct, indirect, and possible related disaster deaths were used for case ascertainment. 

You can view the entire report at https://www.dshs.texas.gov/news/updates/SMOC_FebWinterStorm_MortalitySurvReport_12-30-21.pdf.

Public health surveillance conducted in general population sheltering locations (i.e., evacuation shelters) for the detection of infectious disease and injury is colloquially known as shelter surveillance. The objectives of shelter surveillance in evacuation shelters include:

• Monitoring shelter clients and staff for infectious disease/injury so that interventions may be implemented
• Providing for local situational awareness on the health status of the shelter population
• Creating a daily statewide picture for public health and emergency management briefings

Shelter Surveillance Components

Shelter surveillance conducted in Texas includes the following components:

• Ongoing monitoring and daily tracking of illness/injury complaints. Ideally, this activity is conducted by shelter staff manning the first aid station or a station set up to provide disaster health services within a shelter.  A General Shelter Surveillance Summary Form has been developed to capture the health complaints of shelter clients and staff over a 24-hour reporting period. The form is designed to be completed by non-medical (or medical) personnel at evacuation shelters. and submitted to the local health department in the city or county where the shelter is located.
• Ongoing reporting of illness/injury complaints to public health. The General Shelter Surveillance Summary Form is a reporting form. Shelter managers or their designees submit completed forms to the local health department by the reporting deadline set by the DSHS State Medical Operation Center (SMOC).
• Ongoing analysis and interpretation of health complaint data by public health. Local health departments may follow up to investigate any illness/injury complaints of concern.  They will also conduct cluster or outbreak investigations when necessary.
• Implementation of public health interventions to control and mitigate the spread of disease/ injury. Local health departments conduct this activity as part of a public health investigation.
• Generate a statewide picture of the health status of shelter populations. This activity is conducted by the SMOC’s Disaster Shelter Surveillance Unit.

Shelter Surveillance Resources

Form(s) completed by evacuation shelters:

• General Shelter Surveillance Summary Form PDF

Guidance for local health departments on implementing shelter surveillance:

• Instructions for Local Health Departments and DSHS Public Health Regions PDF