On the outskirts of a rural Midwestern town, a man steps through the door of a trailer, which, along with three other connected trailers, forms a large, mobile medical facility. Earlier in his home, researchers had asked him about his medical history and lifestyle; now in the trailers, they analyze his blood, measure his height and weight, and assess his cardiovascular fitness on a treadmill, among other tests.

A few hours later, he walks out with a special device attached to a belt under his shirt that records how much he is moving, including the acceleration of his motion, so researchers can tell the difference between activities like walking and running. He wears it when he's awake for 1 week, then slips the device into a padded envelope and drops it in the mail. The trailers are gone, on their way to another city.

The accelerometer, worn under the shirt in NHANES, accurately measures an individual's activity, improving data collection for behavioral research studies.

"Technology such as this can be used in 1, 10, or thousands of people to understand more comprehensively the variety of factors that impact cancer incidence," explains DCCPS Director Dr. Robert Croyle. "It can also be used to monitor the quality of cancer care, and to improve communication between patients and their health care providers."

The concept of remote devices to record health information is not new, notes Dr. Audie Atienza, a program director in the DCCPS Health Promotion Research Branch and co-editor of a new book on the subject, The Science of Real-Time Data Capture. "In the 1970s, cardiovascular medicine researchers assessed the ambulatory heart rates of patients in real-time using remote technology," he says, "but now it's extending into other domains, such as cancer, and the technology is becoming much more powerful and portable. As a result, multiple aspects of health and disease can now be measured in real time and in the real world."

The benefit of these tools is that they improve accuracy by reducing human error. And that's extremely important, says Dr. Richard Troiano, an epidemiologist in the DCCPS Applied Research Program who works on the project, because accurate measurement of peoples' behaviors and other risk factors is essential to understanding what really causes cancer and how it can be prevented.

In the physical activity component of the NHANES project, for example, "we found a striking difference between what people said that they were doing and what we were able to measure them doing with the accelerometers," Dr. Troiano explains. "Survey participants reported much more physical activity than we measured during the time they wore the accelerometer."

Meanwhile, as part of the recently launched NIH-wide Genes, Environment and Health Initiative, grantees are developing a cell phone equipped with camera, image processor, and voice recognition to assess diet; a cell phone integrated with a miniaturized accelerometer, heart rate monitor, and GPS device to assess physical activity; and a cell phone coupled with an e-watch that allows for real-time assessment of psychosocial stress, explains Dr. Jill Reedy, who oversees the division's participation in the initiative.

Clearly, Dr. Croyle says, technology is changing the whole field.

—Brittany Moya del Pino