Trial Information

Actigraph Accelerometer Validation Study

The NCI is collaborating with other NIH Institutes on a proposed extramurally funded
longitudinal study of Hispanic subpopulations in the United States referred to as the
Hispanic Community Health Study (HCHS). Hispanic populations are understudied with respect
to many diseases and risk factors. To better understand the relationship between physical
activity and chronic disease, and to make specific activity prescriptions, better methods
are needed to improve the validity and reliability of physical activity assessment
instruments to assess the frequency, duration, and intensity of physical activity. In
preparation for use in the HCHS, NCI plans to evaluate a new type of accelerometer, a small
device worn on a belt at the waist that measures and records movement, capturing movement
intensity and duration and associating it with clock-time. This new accelerometer will be
used in the HCHS to allow examination of levels as well as patterns of activity. Physical
activity was measured with accelerometers in the nationally representative 2003-2006
National Health and Nutrition Examination Survey (NHANES). Between the time of the NHANES
and the HCHS, there has been a change in the technology of the accelerometer used in NHANES.
To allow comparison of the physical activity data that will be collected in the HCHS to the
data collected with the previous technology used in NHANES, a cross-validation study is
needed. The proposed study, the ActiGraph Accelerometer Validation Study, will compare the
ActiGraph model 7164 used in NHANES with the new model GT1M to be used in the HCHS by
simultaneously collecting physical activity data using both ActiGraphs under different
circumstances of walking or jogging. The study will recruit 120 men and women ages 18-74,
corresponding to the age range of the HCHS. Normal weight, overweight and obese participants
will be included in each age/gender cell. Because the devices measure movement, it is not
essential that the study participants be from any particular ethnic group. To derive
comparable data for the 2 devices, the 2 accelerometer models will be worn on a belt, with
one positioned on each hip. Study participants will be asked to walk/jog around a track for
a known distance at several self-selected paces. Minute-by-minute and summary data from the
two devices will be evaluated for comparability.