Frequently Asked Questions (FAQs)
Q: How much does it cost to use ASA24?
A: As part of its mission to advance measures and methods for monitoring cancer-related behaviors and other risk factors, the Risk Factor Monitoring and Methods Branch provides tools and resources to the extramural research community. Consistent with that, ASA24 is available for use free of charge to researchers, clinicians, and teachers.
Costs to consider when planning a study that uses ASA24 include system and labor costs associated with uploading study details, including respondent usernames and recall dates. Costs also are associated with contacting and monitoring respondents, assessing data quality, and analyzing data. The labor and resources needed by researchers and associated costs to configure and manage studies using ASA24 are within the purview and the responsibility of users.
Q. How can a researcher gain access to ASA24?
A: A researcher, clinician or teacher who wishes to use ASA24 can visit the Researcher Web site
to register a new study. Within 1 to 2 business days of the submission of basic information about the study (e.g., study name and description, start and end dates), NCI will either approve the use of ASA24 or contact the researcher for further information. Once the study is approved, access information for the Researcher Web site will be sent by e-mail. Detailed instructions for researchers can be downloaded from the Researcher Web site.
Q: Can I use ASA24 with students in a class that I am teaching?
A: Yes, ASA24 can be used as an instructional tool. Teachers or professors should register to use ASA24 using the same process that would be used for a study (see FAQ 2
). Refer to the Researcher Web site instructions available from the Researcher Web site for details.
Q: What resources are available for researchers interested in using ASA24?
A: Researchers can access a demonstration version of the Respondent Web site to complete a demo recall. Detailed instructions for researchers interested in accessing the full software can be downloaded from the Researcher Web site. Sample analysis files and data dictionaries are also available from the Researcher Web site.
Q: Does the Spanish version of ASA24 require separate registration?
A: No, researchers do not need to specify the language that will be used by respondents when registering a study. Rather, when a respondent accesses the Respondent Web site, he or she will have the option of completing recalls in either English or Spanish.
Note that even though study participants may complete their recalls in Spanish, information on the Researcher Web site, including all data in reports and analytic files, is available in English only.
Q: Can ASA24 be translated to other languages and/or modified for other settings?
A: Yes, the ASA24 Respondent Web site can be translated to other languages besides English and Spanish. However, ASA24 was developed for use in the US, and the foods included reflect those consumed by the US population. Modification of ASA24 for use in other settings where food consumption patterns differ is feasible but requires substantial effort and funding. Please contact Amy Subar
for further information.
Q: Can ASA24 be accessed using dial-up Internet access?
A: No, ASA24 works using high-speed Internet access only. In addition, researchers who use wireless Internet connections have reported difficulties with the Respondent Web site. Wireless internet connection can be affected by numerous factors, including the terrain of the location of use. Testing the reliability of the wireless connection in the study’s location before fielding a study is strongly recommended.
Q: Does ASA24 work with all common web browsers?
A: ASA24 has been tested on Microsoft Internet Explorer 6, 7, and 8 for Windows, Mozilla Firefox 3 for Windows and OSX, Mozilla Firefox 3.5 for Windows and OSX, Apple Safari 4 for Windows and OSX, and Google Chrome 2 for Windows.
Q: Can ASA24 be downloaded onto a laptop or other electronic device?
A: No, ASA24 is a web-based program and is not downloadable.
Q: Can ASA24 be completed on a mobile device?
A: No, ASA24 cannot be viewed on the small screens of mobile devices. ASA24 has been designed to be completed on a monitor size of at least 10”, though greater than 13” is recommended.
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General ASA24 Information
Q: What questions and probes are used during the ASA24 recall interview?
A: The passes, questions and probes used are drawn from the USDA’s Automated Multiple-Pass Method (AMPM), which has been modified to enable automated, self-administered recalls. This modification process has been documented in a published manuscript
. Details on the passes of the recall interview are also available
Q: What information is available on the validity of ASA24?
A: The ASA24 Respondent Web sites are based on validated tools, including the 24-hour recall and USDA's AMPM. Three studies
are underway to test the performance of ASA24 as a dietary assessment tool.
Q: How is ASA24 updated?
A: ASA24 is linked to the updates of the underlying databases, including AMPM, the Food and Nutrient Database for Dietary Surveys (FNDDS), the National Health and Nutrition Examination Survey (NHANES) Dietary Supplement Database, and the MyPyramid Equivalents Database (MPED). Soon after those systems are updated, NCI will update ASA24.
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Study Design & Respondent Access
Q: What study sample size can be accommodated by ASA24?
A: ASA24 was designed to manage multiple, large epidemiologic studies simultaneously. Should a researcher wish to use ASA24 for a very large study (i.e., thousands of respondents), it is advisable to arrange the timing of recalls so that not all respondents are attempting to access the system on the same days.
Information on the scheduling of recalls is detailed in the instructions available from the Researcher Web site.
Q: How many recalls can be completed by each respondent?
A: Each respondent is assigned a username as part of the study configuration process. This username can be used to complete a maximum of 24 recalls. Both fully completed recalls and recalls that are started but not completed count toward the maximum.
Q: How is respondent confidentiality maintained within ASA24?
A: Researchers do not provide NCI or the ASA24 system with any identifying data for study respondents. Rather, researchers specify a user ID for each respondent and download system-generated usernames and encrypted passwords that respondents use to access the application.
ASA24 also does not collect any identifying data directly from respondents. However, IP address information is accessed for the purpose of routing information between the server and the respondent's computer -- often the IP address is that of the user's Internet Service Provider (ISP). IP addresses are not stored or tracked by ASA24. However, logs of connections are kept for audit trail purposes. This information is not mined in any way but would be available if there were a legal obligation to release it.
Q: Can ASA24 be used as an interviewer-administered tool?
A: ASA24 was not designed for this purpose, but some researchers have used it as a tool to guide interviewers through the administration of recalls. For example, this might be helpful for participants with low literacy skills. It is advisable to have the ASA24 interface accessible to respondents to make use of audio and visual cues such as the portion size images.
Q: Can ASA24 be adapted to a paper-based tool or used to enter recall data collected using a paper-based tool?
A: ASA24 was designed to collect recall data directly from respondents based on USDA's Automated Multiple-Pass Method (AMPM). The recall is respondent-driven in that the detailed questions asked are based on a series of linked question pathways, with questions being dependent on a previous answer (i.e., the probes used to collect details such as portion size depend on the food or drink reported [e.g., orange] and the form in which it was consumed [e.g., whole fruit, slices]).
The ASA24 system contains more than 325 unique detailed probe questions, almost 10,000 portion-size images, and more than 10 million food pathways. Obtaining the level of detail that ASA24 captures using a paper-based tool would be very challenging.
Q: Can ASA24 be used to enter food record data?
A: ASA24 was not designed for this purpose, and because it is intended for the collection of recall data, respondents are prompted to report intake for the previous day from midnight to midnight. It is currently not possible to modify the intake date within the system. However, respondents can be instructed to enter their data into ASA24 in real time (for the current day). The researcher would then need to modify the intake dates in their output files outside of the ASA24 system as appropriate. If food record data are collected using a paper-based tool and then later entered into ASA24, extensive details on the foods and drinks reported are needed to obtain accurate analyses (see FAQ 18
Q: How will study participants be directed to the ASA24 program?
A: It is the responsibility of researchers to contact study participants with information about how to access the Respondent Web site and when. NCI will not have access to any contact information or identifying information for respondents.
Q: Can study participants be redirected to the ASA24 Respondent Web site from an existing study Web site?
A: Yes, respondents can be redirected from a study Web site to ASA24 so that they can complete their recalls without having to log in directly to ASA24. When respondents complete their recalls and exit ASA24, they will be redirected back to the study Web site and a completion status will be returned. In this situation, the researcher will register the study, manage study logistics, and access analytic output files by way of the Researcher Web site as they would with any ASA24 study. To find out more about this option, please contact the ASA24 Support Team
Q: When will study participants be able to access ASA24 to complete their recalls?
A: It is up to the researcher to determine the schedule for the completion of recalls by study participants. ASA24 will permit both scheduled and unscheduled administrations of 24-hour recalls.
Q: How long does it take for a respondent to complete ASA24?
A: The first time a respondent completes a recall is likely to take longer than subsequent recalls. Based on limited pilot testing, it is estimated that a recall takes 20 to 30 minutes to complete, depending on the complexity of a respondent's intake the previous day and how quickly he or she learns the software.
Q: Can ASA24 be used with children?
A: ASA24 was initially developed for use with adults. ASA24-Kids-2012
, a version of the Respondent Web site modified for use with school-aged children, is also available for use with children aged 10 years and older. To make the software more user-friendly and appealing for this age group, ASA24-Kids includes a shorter list of foods and beverages from which to choose based on National Health and Nutrition Examination Survey (NHANES) recall data for children. It asks fewer detailed questions about food preparation, which leads to more default coding of foods using the Food and Nutrient Database for Dietary Surveys (FNDDS). See Registering to Use ASA24
for details on how to request the use of ASA24-Kids.
Q: Does the system allow entering recipes or saving favorites?
A: No, ASA24 does not yet do this. We are considering adding these features in the future.
Q: Can foods or supplements be added to ASA24 for a particular study?
A: No. ASA24 includes foods and drinks from the Food and Nutrient Database for Dietary Surveys (FNDDS) and supplements reported in the National Health and Nutrition Examination Survey (NHANES). At this time, it is not possible to add foods, drinks, or supplements to the database.
Q: What resources are available to assist respondents in completing 24-hour recalls using the ASA24 Respondent Web site?
A: The Respondent Web site features an animated character that guides respondents through the recall interview using audio and visual cues. In addition, a “help” document providing responses to frequently asked questions is available through a link at the top right corner of the Respondent Web site.
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Output & Data Management:
Q: What analytic output files are available?
A: Researchers can request any or all of the following analytic files (the versions of the databases noted below apply to ASA24-2011 and ASA24-Kids-2012):
- My Selections: Names of foods and supplements reported and probe questions and answers for each respondent, by recall day.
- Individual Foods and Nutrients: Food and Nutrient Database for Dietary Studies (FNDDS) version 4.1 food codes, gram weights and nutrients for each food reported by each respondent, by recall day.
- Individual Foods and MyPyramid Equivalents: FNDDS version 4.1 food codes, gram weights, and MyPyramid Equivalents for each food reported by each respondent, by recall day. MyPyramid Equivalents are based on version 2.0 of the USDA's MyPyramid Equivalents Database (MPED) supplemented with the USDA Center for Nutrition Policy and Promotion's MPED Addendum to allow compatibility with FNDDS 4.1; nutritionists on the ASA24 team imputed values for nine food codes for which MyPyramid Equivalents have not yet been assigned by USDA. MyPyramid Equivalents can be used by researchers to derive Healthy Eating Index (HEI) variables for the calculation of HEI scores.
- Daily Total Nutrients: FNDDS version 4.1 nutrients from all foods reported, by respondent and recall day.
- Daily Total MyPyramid Equivalents: FNDDS version 4.1 food codes, gram weights, and MyPyramid Equivalents from all foods reported, by respondent and recall day.
For studies in which the optional supplements module is selected, researchers can access three additional analytic files:
- Individual Supplements: National Health and Nutrition Examination Survey (NHANES) supplement codes and nutrients for each supplement reported by each respondent, by recall day.
- Daily Total Supplements: Nutrients from all supplements in a given day, by respondent and recall day.
- Daily Total Nutrients from Foods and Supplements: Nutrients from foods and supplements, by respondent and recall day.
Q: What nutrients and food groups are included in the analytic files?
A: For studies using ASA24-2011 and ASA24-Kids-2012, analyses are provided for all nutrients available in FNDDS version 4.1
and food groups included in MPED
. MyPyramid Equivalents are based on version 2.0 of the USDA's MyPyramid Equivalents Database (MPED) supplemented with the USDA Center for Nutrition Policy and Promotion's MPED Addendum
to allow compatibility with FNDDS 4.1; nutritionists on the ASA24 team imputed values for nine food codes for which MyPyramid Equivalents have not yet been assigned by USDA. Sample analytic files and data dictionaries are available from the Researcher Web site.
Q: Can data for other nutrients be added to ASA24?
A: The analytic output files available for download from the Researcher Web site include data on food type and quantity as well as Food and Nutrient Database for Dietary Surveys (FNDDS) food codes. Researchers can link these data with external sources to perform further analyses beyond those available within ASA24. The capability to add nutrients within the ASA24 system may be possible in the future.
Q: What fortified foods and supplements are included in ASA24?
A: Respondents can select fortified foods that are included in FNDDS version 4.1 and supplements reported in the 2007-2008 NHANES.
Q: Does ASA24 assess usual salt use?
A: ASA24 does not ask specifically about salt use. However, most of the dietary sodium in the US diet comes from processed food that is captured by ASA24.
A report from USDA (PDF) indicates that the Automated Multiple-Pass Method (AMPM), which is the basis for ASA24, provides valid sodium intake estimates without application of adjustments to account for salt added during cooking and food preparation. For this reason, a salt intake module querying about salt use is not planned for ASA24.
Q: What processing do recall data entered into ASA24 by respondents undergo?
A: Recall data are coded using the nutrient, food, and supplement databases noted in the list of available analytic files (see FAQ 28
). No other processing or quality control measures are conducted. As with any data collection initiative, researchers should carefully assess the quality of the data collected from their study respondents. To assist researchers in this effort, output files include a flag to indicate whether each recall was completed (i.e., whether the respondent completed the program up to and including the last question).
However, “incomplete” recalls may be deemed acceptable by a researcher depending upon how far the respondent made it in the program and what data are missing (e.g., in the food module, details on portion size versus a response to the final question which queries whether the amount of food consumed yesterday was usual). A researcher also may wish to exclude a recall coded as “complete” by ASA24 because the data entered by the respondent are of poor quality.
The output files also include details of items entered by the respondent that could not be found (i.e., “no match found”) to enable researchers to assign or modify codes outside of ASA24. Recalculation of nutrient or food group intakes to account for revised or newly assigned food codes can be done outside of the ASA24 system using FNDDS or any other source available to researchers.
Q: Does ASA24 output include Healthy Eating Index (HEI) scores?
A: ASA24 output includes the variables needed to calculate HEI scores outside the ASA24 system. HEI
is a tool to assess compliance with US dietary guidance.
Q: Once a study has been approved and data collection is underway, when can the researcher access analytic output files?
A: Once data collection is underway, the researcher can visit the Researcher Web site at any time to run analyses. Typically, researchers will be prompted to return to log in to the system the following day to access results in the analytic files. In some settings (e.g., clinical or classroom uses), researchers may wish to obtain real-time reports for a specific individual; this type of request will take approximately 10 minutes to process. Output files do not have specific formatting for the lay public.
Q: Who will be able to request and access analytic output files?
A: The researcher and any staff who have been registered to the study (and who therefore have a valid username and password for the ASA24 Researcher Web site) will be able to request and access analytic output for their respondents.
Q: Can the software provide feedback to study participants?
A: No, ASA24 does not currently provide any direct feedback to respondents. Researchers may use the analytic output files available for download to design reports for respondents outside of ASA24.
Q: What security measures are in place to protect recall data entered into ASA24 and resulting tracking and analytic files?
A: ASA24 does not ask for nor store any personal identifying information. Response data are secured at the hosting site using industry standard security controls, including firewalls and encryption. All data entered into ASA24 at the respondent’s computer is encrypted by the internet browser (e.g., Internet Explorer, Firefox) before they are transmitted to our servers using Secure Socket Layer (SSL) Technology. SSL allows for the authentication of the sending and receiving computers.
Only a particular study’s investigator(s) and the ASA24 operations team can access response data. Access is gained through usernames and strong passwords.
Q: How long will data remain accessible from the ASA24 Researcher Web site following the completion of a study?
A: Data are maintained in the system for a period of at least one year (unless the researcher requests an earlier date for data purging). Researchers will be notified before their data are removed from the system.
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Citing ASA24 in Publications & Presentations:
Q: What is the recommended citation for ASA24?
A. Please cite ASA24 as follows, depending on the version used in your study:
- Automated Self-Administered 24-Hour Recall (ASA24)-Beta-2009. Bethesda, MD: National Cancer Institute.
- Automated Self-Administered 24-Hour Recall (ASA24)-2011. Bethesda, MD: National Cancer Institute.
- Automated Self-Administered 24-Hour Recall (ASA24)-Kids-2012. Bethesda, MD: National Cancer Institute.
You may also consider including the following sentence in your manuscript: Dietary intake data were collected and analyzed using the Automated Self-Administered 24-hour Recall (ASA24) system, version, developed by the National Cancer Institute, Bethesda, MD.
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ASA24™ is a trademark of DHHS.