Body Mass Index clinical trials

Multiphase Optimization Trial of Incentives for Veterans to Encourage Walking

Regular physical activity (PA) is essential to healthy aging. Unfortunately, only 5% of US adults meet guideline of 150 minutes of moderate exercise; Veterans and non-Veterans have similar levels of PA. A patient incentive program for PA may help. Behavioral economics suggests that the chronic inability to start and maintain a PA routine may be the result of "present bias," which is a tendency to value immediate rewards over rewards in the future. With present bias, it is always better to exercise tomorrow because the immediate gratification of watching television or surfing the internet is a more powerful motivator than the intangible and delayed benefit of future health. Patient incentives may overcome present bias by moving the rewards for exercise forward in time. Recent randomized trials suggest that incentives for PA can be effective, but substantial gaps in knowledge prevent the implementation of a PA incentive program in Veterans Affairs (VA). First, incentive designs vary considerably. They vary by the size of the incentive, the type of incentive (cash or non-financial), the probability of earning an incentive (an assured payment for effort or a lottery-based incentive), or whether the incentive is earned after the effort is given (a gain-framed incentive) or awarded up-front and lost if the effort is not given (a loss-framed incentive). The optimal combination of these components for a Veteran population is unknown. Second, the evidence about the effective components of incentives comes from studies conducted in populations that were overwhelmingly female; often employees at large companies, with high levels of education and income. VA users, in contrast, are mostly male and lower income, and most are not employed. This is important because the investigators have theoretical reasons to believe that the effects of components of incentives are likely to vary by income and gender. Finally, few studies have managed to design an incentive such that the physical activity was maintained after the incentive was removed. Indeed, a common theme in incentivizing health behavior change is the difficulty in sustaining behavior change once the incentives are removed.