A Randomized Controlled Trial of Employer Matching of Employees' Monetary Contributions to Deposit Contracts to Promote Weight Loss

Abstract

Purpose: To test whether employer matching of employees' monetary contributions increases employees' (1) participation in deposit contracts to promote weight loss and (2) weight loss.

Design: A 36-week randomized trial.

Setting: Large employer in the northeast United States.

Participants: One hundred thirty-two obese employees.

Interventions: Over 24 weeks, participants were asked to lose 24 pounds and randomized to monthly weigh-ins or daily weigh-ins with monthly opportunities to deposit $1 to $3 per day that was not matched, matched 1:1, or matched 2:1. Deposits and matched funds were returned to participants for each day they were below their goal weight.

Measures: Rates of making ≥1 deposit, weight loss at 24 weeks (primary outcome), and 36 weeks.

Analysis: Deposit rates were compared using χ(2) tests. Weight loss was compared using t tests.

Results: Among participants eligible to make deposits, 29% made ≥1 deposit and matching did not increase participation. At 24 weeks, control participants gained an average of 1.0 pound, whereas 1:1 match participants lost an average of 5.3 pounds (P = .005). After 36 weeks, control participants gained an average of 2.1 pounds, whereas no match participants lost an average of 5.1 pounds (P = .008).

Conclusion: Participation in deposit contracts to promote weight loss was low, and matching deposits did not increase participation. For deposit contracts to impact population health, ongoing participation will need to be higher.

Trial registration: ClinicalTrials.gov NCT01167634.

Keywords: behavioral economics; incentives; obesity; weight loss; workplace.

© The Author(s) 2016.

Figures

Appendix Figure 1.. 24 Week Weight Change and Participant Deposit Amounts by Arma

Each bubble represents an individual participant. The size of the bubble signifies the total amount (ranging from $0 to $504) that participant deposited over the course of the 24-week intervention.

Figure 1.

Flow of Study Participants

Figure 2.. Mean Cumulative Weight Change by Montha

a16 missing 36-week weights were imputed. The difference between the no match and control arms at 36 weeks remained statistically significant when we used only the 116 non-missing 36-week weights.