According to a study appearing in the Dec. 10 issue of the Journal of American Medical Association, financial incentives for weight loss are effective for shedding pounds, at least over the short term.
by Crystal Phend, Staff Writer, MedPage Today
PHILADELPHIA, Dec. 9 — Financial incentives for weight loss appear to be effective for shedding pounds, at least over the short term, researchers found.
Patients motivated to meet weight loss targets in order to win money — or not lose it — were 7.7 to 9.4 times more likely to meet the 16 week-targets than those without such incentives, Kevin G. Volpp, M.D., Ph.D., of the University of Pennsylvania here, and colleagues reported in the Dec. 10 issue of the Journal of the American Medical Association.
However, these short-term benefits in the randomized controlled trial faded over the months after the incentive intervention ended, the researchers noted.
But the findings provide evidence that daily feedback tied to incentives can keep patients engaged with unusually low dropout rates, they said.
It works by turning the drive for instant gratification into a diet strategy, they said.
The field of behavior economics suggests that the brain values immediate rewards — such as the pleasure of eating, which often contributes to weight gain — above delayed benefits like good health.
Dr. Volpp’s group hypothesized that small but frequent financial rewards would provide an alternative source of gratification.
Their randomized controlled trial included 57 patients at the Philadelphia VA Medical Center with a body mass index between 30 and 40 kg/m2 who participated in a program to lose 16 pounds over 16 weeks.
After an initial one-on-one consultation with a dietician about diet and exercise, the participants were randomly assigned to monthly weigh-ins without incentives or the same program with one of two financial incentive plans.
Incentive group patients were given daily weight goals and reported progress to study nurses who provided daily feedback via text message on the amount of money earned for reaching goals.
One financial incentive had patients deposit their own money at the beginning of every month, which they could then earn back in matched funds, up to $252 a month, by meeting daily and monthly weight targets.
The other incentive was a daily lottery in which patients could win about $3 for every day they met weight targets with the possibility of winning rewards of $10 or $100. There was a better chance of winning the $10 than the $100.
For the entire intervention, participants earned an average of $378.49 in deposit contract incentives and $272.80 in the lottery.
Daily call-in rates were high at 94% to 97% with lost-to-follow-up rates much lower than normal for weight loss studies, “suggesting that this approach was successful in keeping participants engaged,” the researchers said.
Over the course of 16 weeks, the incentive groups were significantly more successful at shedding pounds.
The average lost was 3.9 pounds in the control group compared with 13.1 pounds in the lottery group (P=0.02) and 14.0 pounds in the deposit contract group (P=0.006).
Few participants in the control group met the 16-pound weight loss goal whereas about half of those in the lottery and deposit contract groups did (10.5% versus 52.6% [95% confidence interval 28.9% to 75.6%] and 47.4% [95% CI 24.5% to 71.1%] respectively, P=0.01).
Financial incentives increased the odds of achieving the 16-pound weight loss goal significantly compared with controls (odds ratio 7.7 for deposit, 95% CI 1.4 to 42.7, and OR 9.4 for lottery, 95% CI 1.7 to 52.7).
The results were essentially unchanged by adjustment for age and sex and were similar across age, income, and initial body mass index categories.
After the intervention, patients regained weight as expected.
However, at seven months the incentive groups still had a significant net weight loss compared with their initial weight — 9.2 pounds in the lottery group (P=0.01) and 6.2 pounds in the deposit contract group (P=0.03) — whereas the control group had only a trend (4.4 pounds, P=0.06).
Dr. Volpp’s group noted that the magnitude of weight loss in the incentive groups has been shown to improve outcomes such as blood pressure, glycemic control, and serum lipid levels.
Whether longer-term use of financial incentives would have helped patients sustain their weight loss would need further study, they said.
“An important outstanding question is the relative cost-effectiveness of different approaches to achieving sustained weight loss,” Dr. Volpp’s group wrote, “because maintenance of successful weight loss has been a big challenge in all weight loss programs.”
They cautioned that generalizability of the findings might have been limited by the primarily male veteran population at a single center who, as volunteers, might have been more motivated than the average obese patient.
The study was supported by the National Institute on Aging, the Boettner Center for Pensions and Retirement Security at the University of Pennsylvania, the National Institute of Child Health and Development Population Research Infrastructure Program, the U.S. Department of Agriculture, Economic Research Service, and the Hewlett Foundation.
Explain to interested patients that financial incentives appeared effective as motivation for short-term weight loss.
Note that long-term weight loss is also important for health outcomes.
Note that the single center study included primarily men.
Published: December 09, 2008
Reviewed by Zalman S. Agus, MD; Emeritus Professor, University of Pennsylvania School of Medicine.
Primary source: Journal of the American Medical Association
Source reference: Volpp KG, et al “Financial incentive-based approaches for weight loss: a randomized trial” JAMA 2008; 300: 2631-2637.
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