Trial Information

Feasibility Study of a Web-Based Automated Self-Administered 24-hour Dietary Recall (ASA 24) and a Physical Activity 24-Hour Recall (ACT24)

In spite of long-standing hypothesis relating diet and physical activity to several cancers,
diet and physical activity-cancer associations have been modest at best and often
inconsistent in epidemiologic studies. Investigators around the world have become
increasingly concerned that error in the measurement of both diet and physical activity is
compromising our ability to detect these important but modest associations. Most commonly
used diet and physical activity assessment methods have been based on a relatively small set
of questions (e.g. 124 food items consumed or 5-10 physical activities in the past 12
months). Recent developments in computer technology provide an opportunity to use
internet-based instruments to assess an individual's diet and physical activity more
accurately and cost effectively.

NCI has been developing two web-based instruments, an automated self-administered 24-hour
dietary recall (ASA24) and a physical activity 24-hour recall (ACT24), which can be
administered several times over a year. Although these two instruments have the potential
to qualitatively improve exposure assessment (at relatively low cost), they need to be
evaluated for feasibility before being incorporated in cohorts on a large scale. Therefore,
we propose to test ASA24 and ACT24 among AARP members aged 50 years and over to evaluate
technical problems, determine response rates, and estimate the range of dietary intake and
physical activity. In addition, we propose to include in this feasibility study two
web-based versions of conventional questionnaires (lifestyle and medical history
questionnaire and diet history questionnaire) as well as two software systems needed to
conduct a web-based study (the automated Study Management System and Web Survey Management
System). We will initially target 15,000 AARP members, expecting that approximately 2,000
individuals will agree to participate in the study and about 1,250 participants will
complete ASA24 and ACT24 twice.

These web-based instruments and accompanying system tools represent a novel approach to
carrying out diet and lifestyle research. The computerized, web-based study method can be
applied to any observational study, large or small, case-control or cohort, as well as
randomized controlled trials. This feasibility study will provide an opportunity to assess
the feasibility of constructing large web-based cohort studies and characterize potential
participants.