Obesity
Conditions
Brief summary
This study aims to evaluate the effectiveness of financial incentives in improving and maintaining weight loss.
Detailed description
Study participants will be obese volunteers recruited from a major community-based weight loss program (Weight Watchers), who have lost at least 5kg during the 4-6 months prior to enrolling in the study. Among these participants, the following will be assessed: 1. The effectiveness of a daily lottery-based financial incentive, relative to the control group, on weight loss and weight maintenance; 2. The effectiveness of a direct payment incentive, relative to the control group, on maintenance of weight loss; 3. Assess the comparative effectiveness of lottery-based and direct payment financial incentives on weight loss and maintenance; 4. The degree to which weight loss is maintained in the intervention groups relative to usual care during the 6 months following cessation of the intervention will also be determined. During Phase I, incentives will be provided to some study participants (direct payment and lottery arm) for the first 6 months and subjects will be followed for 6 more months to examine effects following cessation of incentives.
Interventions
BEHAVIORALFinancial incentive
Participants in the direct payment and lottery arms will receive financial incentives as part of the intervention. See arm descriptions for more detail.
Sponsors
Duke University
National Institute on Aging (NIA)
University of Pennsylvania
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
30 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Adults age 30-80 * BMI between 30 and 45 prior to starting Weight Watchers * Have a documented weight loss of at least 5kg in the past 4-6 months before enrolling * Stable health
Exclusion criteria
* Substance abuse * Bulimia nervosa or related behaviors * Pregnancy or breast feeding * Medical contraindications to counseling about diet, physical activity, or weight reduction * Unstable mental illness * Screen positive for pathological gambling on the basis of the 10 item DSM-IV criteria (excluded if meets 5 or more criteria) * Individuals unable to read consent forms or fill out surveys in English
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in Weight From Baseline to 6 Months | 6 months |
| Change in Weight From Baseline to 12 Months | 12 months |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Lottery In addition to the incentives for the 3-, 6-, 9-, & 12-month weigh-ins, participants who meet their daily goal will be eligible for the daily lottery during the first 6 months of the study. The expected daily winning for the lottery is the same as for the direct payment arm. All daily incentive earnings will be paid out after verifying participants' weights during an in person weigh in at a Weight Watchers location at months 3 and 6. Winnings will be proportional to weight loss. For example, if a participant's goal was to lose 6 pounds by month 3, but he/she only lost 3 pounds, that participant would only receive 50% of their total eligible winnings.
Similar to the control arm, participants will receive daily feedback for months 1-6 and will be observed without intervention in Phase II (months 7-12). The weigh-ins at 9- and 12-months will also be required. | 77 |
| Direct Payment In addition to the incentives for the 3-, 6-, 9-, & 12-month weigh-ins, participants who meet their daily goal will be eligible to receive an incentive for each day their goal is met during the first 6 months of the study. All daily incentive earnings will be paid out after verifying participants' weights during an in person weigh in at a Weight Watchers location at months 3 and 6. Winnings will be proportional to weight loss. For example, if a participant's goal was to lose 6 pounds by month 3, but he/she only lost 3 pounds, that participant would only receive 50% of their total eligible winnings. | 75 |
| Control No other financial incentive other than for the 3-, 6-, 9-, & 12-month weigh-ins and surveys. Participants will receive daily feedback for months 1-6 and will be observed without intervention in Phase II (months 7-12). Two weigh-ins will be required during Phase II, one at 9 months and the other at 12 months. | 39 |
| Total | 191 |
Baseline characteristics
| Characteristic | Lottery | Total | Control | Direct Payment |
|---|---|---|---|---|
| Age, Continuous | 48.8 years STANDARD_DEVIATION 10.3 | 49.0 years STANDARD_DEVIATION 10.5 | 50.1 years STANDARD_DEVIATION 10 | 48.6 years STANDARD_DEVIATION 11 |
| BMI ≥35 kg/m2 at randomization | 26 Participants | 69 Participants | 14 Participants | 29 Participants |
| BMI measures BMI at randomization | 32.3 kg/m^2 STANDARD_DEVIATION 4.1 | 32.5 kg/m^2 STANDARD_DEVIATION 4.1 | 32.6 kg/m^2 STANDARD_DEVIATION 4.1 | 32.8 kg/m^2 STANDARD_DEVIATION 4.3 |
| BMI measures BMI at start of Weight Watchers | 36.5 kg/m^2 STANDARD_DEVIATION 4.4 | 36.7 kg/m^2 STANDARD_DEVIATION 4.3 | 36.9 kg/m^2 STANDARD_DEVIATION 4.5 | 36.8 kg/m^2 STANDARD_DEVIATION 4.1 |
| Eating behaviors by Three-Factor Eating Questionnaire Cognitive restraint scale | 62.0 Scores on a scale STANDARD_DEVIATION 15 | 62.3 Scores on a scale STANDARD_DEVIATION 14.4 | 62.4 Scores on a scale STANDARD_DEVIATION 12.8 | 62.6 Scores on a scale STANDARD_DEVIATION 14.6 |
| Eating behaviors by Three-Factor Eating Questionnaire Emotional eating scale | 58.7 Scores on a scale STANDARD_DEVIATION 23.8 | 59.9 Scores on a scale STANDARD_DEVIATION 24.5 | 55.8 Scores on a scale STANDARD_DEVIATION 27.2 | 63.3 Scores on a scale STANDARD_DEVIATION 23.5 |
| Eating behaviors by Three-Factor Eating Questionnaire Uncontrolled eating scale | 44.4 Scores on a scale STANDARD_DEVIATION 15.6 | 45.1 Scores on a scale STANDARD_DEVIATION 16 | 41.8 Scores on a scale STANDARD_DEVIATION 16.1 | 47.6 Scores on a scale STANDARD_DEVIATION 16.2 |
| Education College graduate | 28 participants | 55 participants | 16 participants | 11 participants |
| Education Less than college | 26 participants | 72 participants | 11 participants | 35 participants |
| Education Post-college degree | 23 participants | 64 participants | 12 participants | 29 participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 8 Participants | 2 Participants | 4 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 75 Participants | 183 Participants | 37 Participants | 71 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Household income ≥US $100,000 | 29 Participants | 72 Participants | 13 Participants | 30 Participants |
| Household income <US $50,000 | 12 Participants | 23 Participants | 6 Participants | 5 Participants |
| Household income US $50,000 to <US $100,000 | 36 Participants | 96 Participants | 20 Participants | 40 Participants |
| Household size | 3.2 people per household STANDARD_DEVIATION 1.5 | 3.1 people per household STANDARD_DEVIATION 1.4 | 3.0 people per household STANDARD_DEVIATION 1.2 | 3.0 people per household STANDARD_DEVIATION 1.4 |
| Physical activity in min per week Moderate-vigorous activity min per week | 345 Minutes | 333 Minutes | 390 Minutes | 240 Minutes |
| Physical activity in min per week Total activity min per week | 533 Minutes | 510 Minutes | 600 Minutes | 460 Minutes |
| Physical activity in min per week Walking min per week | 180 Minutes | 148 Minutes | 150 Minutes | 100 Minutes |
| Race (NIH/OMB) American Indian or Alaska Native | 2 Participants | 2 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 3 Participants | 8 Participants | 1 Participants | 4 Participants |
| Race (NIH/OMB) More than one race | 3 Participants | 7 Participants | 3 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 4 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) White | 68 Participants | 170 Participants | 33 Participants | 69 Participants |
| Sex: Female, Male Female | 70 Participants | 175 Participants | 36 Participants | 69 Participants |
| Sex: Female, Male Male | 7 Participants | 16 Participants | 3 Participants | 6 Participants |
| Weight measures Weight at randomization | 89.2 Kilograms STANDARD_DEVIATION 14.3 | 90.2 Kilograms STANDARD_DEVIATION 14.9 | 91.2 Kilograms STANDARD_DEVIATION 15 | 90.7 Kilograms STANDARD_DEVIATION 15.7 |
| Weight measures Weight at the start of Weight Watchers | 100.8 Kilograms STANDARD_DEVIATION 15.7 | 101.6 Kilograms STANDARD_DEVIATION 15.7 | 102.9 Kilograms STANDARD_DEVIATION 15.6 | 101.7 Kilograms STANDARD_DEVIATION 16 |
| Weight measures Weight loss prior to randomization | 11.6 Kilograms STANDARD_DEVIATION 4.4 | 11.4 Kilograms STANDARD_DEVIATION 4.7 | 11.7 Kilograms STANDARD_DEVIATION 4.3 | 10.9 Kilograms STANDARD_DEVIATION 5.1 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 77 | 1 / 75 | 0 / 39 |
| other Total, other adverse events | 2 / 77 | 1 / 75 | 1 / 39 |
| serious Total, serious adverse events | 2 / 77 | 9 / 75 | 4 / 39 |
Outcome results
Primary
Change in Weight From Baseline to 12 Months
Time frame: 12 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control Arm | Change in Weight From Baseline to 12 Months | 2.8 kilograms | Standard Deviation 16.9 |
| Direct Payment | Change in Weight From Baseline to 12 Months | -2.2 kilograms | Standard Deviation 16.2 |
| Lottery | Change in Weight From Baseline to 12 Months | -2.0 kilograms | Standard Deviation 17.9 |
Primary
Change in Weight From Baseline to 6 Months
Time frame: 6 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Control Arm | Change in Weight From Baseline to 6 Months | -1.4 kilograms | Standard Deviation 5.8 |
| Direct Payment | Change in Weight From Baseline to 6 Months | -2.8 kilograms | Standard Deviation 5.8 |
| Lottery | Change in Weight From Baseline to 6 Months | -3.0 kilograms | Standard Deviation 5.8 |
p-value: >0.1Regression, Linear