Evaluating the Effectiveness of Financial Incentives in Promoting Weight Loss Among Obese Individuals

Obesity is a major cause of premature aging and the second leading cause of preventable mortality in the United States, accounting for approximately 110,000 deaths per year. Financial incentives have been effective in modifying a number of health behaviours but they have rarely been applied to weight loss, and to the best of our knowledge never to weight loss by low-SES obese veterans.We propose testing two different approaches to using financial incentives to encourage weight loss. In the first, we build on previous work showing the effectiveness of ‘deposit contracts’, in which subjects are given the opportunity to put their own money at risk if they do not lose weight. In this incentive condition, subjects receive a direct payment conditional on daily weight loss, and an optional additional payment based on their own contributions to the deposit contract. We will match their contribution 1:1 to make the option of depositing their own money attractive to this predominantly low SES population. In the second approach we build on our own prior work using lotteries to promote drug adherence. In this incentive condition, participants are entered into a daily lottery, and receive any payoffs they earn from the lottery only if they stay on track with their weight-loss goal. Given their popularity in the general population, lotteries hold the promise of providing a cost-effective means of motivating weight loss and making efforts to lose weight more salient to obese patients.

Official Title

Evaluating the Effectiveness of Financial Incentives in Promoting Weight Loss Among Obese Individuals.

Conditions

• Obesity

Study Type

Interventional

Study Design

Treatment, Randomised, Open Label, Uncontrolled, Parallel Assignment, Efficacy Study

Further Details

Primary Outcome Measures:

• Mean weight loss will be greater in both experimental groups compared to the control group by the end of 16 weeks

Secondary Outcome Measures: 

• Use the difference in weight loss measured at 16 weeks to project the long-term cost-effectiveness if weight loss is sustained

Study Start

Eligibility & Criteria

Eligibility

• Ages Eligible for Study: 30 Years to 70 Years
• Genders Eligible for Study: Both
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

• BMI between 30-40
• Age between 30-70
• At least moderately interested in losing weight (Self-reported 3,4, or 5 on 5 point scale)

Exclusion Criteria:

• Unstable medical conditions that would likely prevent the subject from completing the study
• Myocardial infarction within 6 months
• Uncontrolled hypertension, defined as BP>170 mm Hg systolic or BP>110 mm Hg diastolic
• Metastatic cancer
• Self-report of 6 or more alcoholic beverages per day
• Severe depression
• Active substance abuse
• Schizophrenia
• Inability to read or severe cognitive deficits that would preclude ability to read consent form or fill out surveys)
• Baseline participation in other weight loss programs

Total Enrolment

57

Contact Details

Please refer to this study by its ClinicalTrials.gov identifier: NCT00520611

Telephone: +1 215 823 4159

Locations

United States, Pennsylvania
Center for Health Equity Research and Promotion      
Philadelphia, Pennsylvania, United States, 19104

Sponsors and Collaborators

University of Pennsylvania

William and Flora Hewlett Foundation

United States Department of Agriculture

National Institutes of Health (NIH)

Investigators

Principal Investigator:      Kevin Volpp, MD, PhD      University of Pennsylvania

Study Director:      George Loewenstein, PhD      Carnegie Mellon University

Study Director:      Leslie John, PhD cand.      Carnegie Mellon University