The measurement error structure of the
ASA24 and ACT24 needs to be evaluated. The iDATA Study will compare
objectively measured energy expenditure, protein, nutrients, and
physical activity with the self-reported intakes of energy,
protein, nutrients, and physical activity using the ASA24 and
ACT24, as well as conventional self-report instruments for
assessing diet and physical activity in a free-living population
aged 50 to 74 years and residing in the Pittsburgh, Pennsylvania
area. To date there has not been a comparable effort to understand
the properties and measurement error structure of self-report
physical activity instruments. The burgeoning epidemic of obesity
highlights the need to explore this in both aspects of energy
balance - dietary intake and energy expenditure through physical
activity. Other studies have shown significant disagreement between
typical, long-term memory-based self-reported activity and
objective wearable motion detection devices. To address this, NCI
has developed a new internet-based instrument, ACT24, which
measures the participant's past 24-hour activities in order to
improve the accuracy of self-reported physical activity. Results
from previous studies have indicated that multiple 24-hour dietary
recalls over the course of one year provide more accurate
information about usual dietary exposure and create less bias in
estimated risk compared with the typical Food Frequency
Questionnaires (FFQ) that asks participants to remember dietary
information over the entire past year. An obstacle to the 24-hour
recall method is that it is typically administered by interviewers,
and is prohibitively expensive to use in large studies, especially
multiple administrations. In response, NCI has developed a
self-administered internet-based version, ASA24, which allows
multiple recalls to be collected at very limited study expense and
relatively low participant burden.
On behalf of this Federal agency, I certify that
the collection of information encompassed by this request complies
with 5 CFR 1320.9 and the related provisions of 5 CFR
1320.8(b)(3).
The following is a summary of the topics, regarding
the proposed collection of information, that the certification
covers:
(i) Why the information is being collected;
(ii) Use of information;
(iii) Burden estimate;
(iv) Nature of response (voluntary, required for a
benefit, or mandatory);
(v) Nature and extent of confidentiality; and
(vi) Need to display currently valid OMB control
number;
If you are unable to certify compliance with any of
these provisions, identify the item by leaving the box unchecked
and explain the reason in the Supporting Statement.