Healthy apps: mobile devices for continuous monitoring and intervention

Abstract

It is now known that nearly half of the toll that illness takes in developed countries is linked to four unhealthy behaviors: smoking, excess alcohol intake, poor diet, and physical inactivity. These common risk behaviors cause preventable, delayed illness that then manifests as chronic disease, requiring extended medical care with associated financial costs. Chronic disease already accounts for 75% of U.S. health-care costs, foreshadowing an unsustainable financial burden for the aging population [1]. We are facing an urgent need to re-engineer health systems to improve public health through behavior change, and technology-supported behavioral change interventions will be a part of 21st-century health care. As new technical capabilities to observe behavior continuously in context make it possible to tailor interventions in real time, the way we understand and try to influence behavior will change fundamentally.

FIGURE 1

Changing a long-standing health risk behavior requires addressing the “4 Ms”: monitoring, modeling, motivating, and modifying.

FIGURE 2

A computer scientist tries to grasp a behavioral scientist’s approach to modeling. Behavioral science theories are models that are specified in advance to guide the design of an intervention. Even though the theory usually lacks quantitative details, behavioral interventions based on theory are more effective at changing behavior than those not based on theory.

FIGURE 3

The smartphone display for the ENGAGED weight loss app [9]. Fans coded in traffic light colors show how much you have already eaten today relative to your daily allowances for calories and fat. The green fan signifies that you can still eat 327 more calories today. However, if you enter the steak that you are thinking about ordering, the fan will turn bright red. You can top up the green physical activity thermometer by accumulating more minutes of moderate intensity exercise until you reach your weekly goal. Wearing the study accelerometer lets your minutes of activity accumulate automatically, but if you forget to wear it, you can get credit (in lighter green) by entering your exercise manually.

FIGURE 4

Color-coded information about team members in the ENGAGED weight loss competition. The left-most flag tab shows each person’s self-reported status. Mark seems to need help. He posted his status as red (danger). His middle (knife and fork) tab is also red, indicating that he has not yet entered any meals today, and his right-most (accelerometer) tab is red, showing that he has not put on his accelerometer. Everyone else on the team has already recorded two meals, but no one has turned the knife and fork tab green by entering three meals. Two people (June and BlueFoxyz) have turned the physical activity tab green by wearing the accelerometer for two-thirds of the day. Everyone else besides Mark has accumulated one-third of a day of accelerometer wear.