CASPER Frequently Asked Questions (FAQ)
What is CASPER?
CDC’s Community Assessment for Public Health Emergency Response (CASPER) is an epidemiologic technique designed to provide public health leaders and emergency managers household-based information about a community. It is quick, reliable, relatively inexpensive, and flexible.
How do I learn more about using CASPER?
The CDC’s National Center for Environmental Health (NCEH) developed the CASPER Toolkitpdf icon to assist personnel from any federal, regional, state, tribal, local, or territorial public health departments in conducting a CASPER during a disaster. The toolkit was created to standardize the assessment procedures. While it is focused on United States disaster response, it may also be adapted for use in a non-disaster or international setting. The CASPER toolkit provides guidelines on questionnaire development, methodology, sample selection, training, data collection, analysis, and report writing and is available on the CDC CASPER website.
How do I request a CASPER in my jurisdiction?
If you would like CDC technical assistance in conducting a CASPER in your jurisdiction, please contact CASPER@cdc.gov.
Is CASPER a rapid needs assessment?
In short, yes. The Community Assessment for Public Health Emergency Response (CASPER) is a type of rapid needs assessment. CASPER is designed to provide accurate and timely data through precise analysis and interpretation for decision makers. Gathering health and basic needs information using valid statistical methods allows public health professionals and emergency managers to prioritize the response/recovery efforts and to make informed decisions regarding the distribution of resources.
What are the objectives of CASPER?
The primary goals of the CASPER are to rapidly obtain information about the needs of an affected community and to assess changes in needs during the response or recovery period. Examples of CASPER objectives include the following:
- Produce household-based population estimates of needs for decision makers
- Determine the critical health needs and assess the impact of the disaster on the community
- Characterize the population residing in the area including any ongoing health effects
- Evaluate the effectiveness of recovery efforts using a follow-up CASPER
CASPER is not intended to deliver food, medicine, medical services or other resources to the affected area or to provide direct services to residents such as cleanup or home repair.
When should you conduct a CASPER?
During a disaster, the local, state, or regional emergency managers or health department officers may decide to initiate a CASPER when at least one of the following conditions occurs:
- The effect of the disaster on the population is unknown.
- The health status and basics needs of the affected population are unknown.
- Response and recovery efforts need to be evaluated.
CASPER methodology can be used in both a disaster and non-disaster setting. CASPERs have been conducted to assess public health perceptions and to estimate needs of a community during a non-disaster setting. Regardless of the setting and objectives, once the decision to conduct the CASPER has been made, it should be initiated as soon as possible. CDC is available for technical assistance for any CASPER, regardless of type (preparedness, response, recovery, non-disaster, etc.)
Can I combine multiple CASPERs and conduct a pooled analysis?
Yes. It is possible to combine CASPERs and conduct a pooled analysis through a meta-analytic approach. Please consult with your local statistician familiar with sampling methodology or reach out to CDC CASPER subject matter experts for technical assistance.
Can I compare results of different CASPERs?
Yes. If identical questions were asked in two or more CASPERs, and the samples are independent from one another, then it is possible to compare the results from different CASPERs using t-tests and chi-square tests. The use of either test depends on whether the outcome variable is continuous or categorical. When comparing, it is important to take into account the complex sampling design in the analysis. Please consult with your local statistician familiar with sampling methodology or reach out to CDC CASPER subject matter experts for technical assistance.
What other analyses can be done using CASPER data?
CASPER is designed for weighted frequencies, percentages, and 95% confidence intervals. Further analysis should be limited due to the confines of the CASPER methodology. Any other estimates (such as stratified analysis) may be unstable and should be viewed with caution. Please consult with your local statistician familiar with sampling methodology or reach out to CDC CASPER subject matter experts for technical assistance to discuss the feasibility of further analysis.
Can I conduct a CASPER on the individual, instead of household, level?
CASPER is designed to be household-based. If individual analysis is desired, please consider if CASPER is the best method for your objectives. If the majority (e.g., 90%) of your questionnaire is household-based but there are some questions that must be asked at the individual level (e.g., Behavioral Risk Factor Surveillance System [BRFSS] questions), it is possible to ask a limited number of questions at the individual level. To do so, you must take the following steps:
- To decrease bias, randomly choose the individual responding to the CASPER questionnaire (e.g., the adult in the household with the next birthday).
- Include a question on your questionnaire to quantify the number of adults in the household.
- “Including yourself, how many adults (over 18) are currently living in this household?” OR
- “Including yourself, how many people currently living in this household are less than 2 years old? 2-17 years old? 18-65 years old? 65 years or older?”
- You would then calculate the total number of adults (i.e., people at least age 18) in your analysis.
- Calculate an “individual” weight in addition to the “household” weight.
Note: Individual level data is only obtained for the individual responding to the CASPER.
Please consult with your local statistician familiar with sampling methodology or reach out to CDC CASPER subject matter experts for any technical assistance.