The Impact of a Workplace Wellness Program in Illinois

Fieldwork by:
Illinois, United States of America
12,459 employees
2016 - 2018
Target group:
  • Adults
Outcome of interest:
  • Health outcomes
Intervention type:
  • Health care delivery
AEA RCT registration number:

Companies across the United States invest billions of dollars per year in workplace wellness programs, even though there is limited experimental evidence regarding their impact. Researchers evaluated the effects of a large-scale workplace wellness program at the University of Illinois at Urbana-Champaign on employee health beliefs, health behaviors, medical spending, and clinical and employment outcomes. The researchers found that financial incentives increased participation in the program, although only to a point. The workplace wellness program changed employees’ health beliefs and some self-reported outcomes, but it had no effects on clinical outcomes including biometrics, medical diagnoses, and medical utilization; medical spending; or employment outcomes. Additionally, among those offered the program, healthier employees enrolled in the program at higher rates, suggesting that workplace wellness programs may shift costs onto employees with lower incomes and with high health care spending and poor health.

Policy issue

Companies across the United States have increasingly looked toward workplace wellness programs to address employee health, productivity, and escalating health care costs. The 2010 Affordable Care Act encourages the adoption of workplace wellness programs by permitting firms to offer participation incentives worth up to 30 percent of the total cost of health insurance coverage. The workplace wellness industry has more than tripled since 2010, generating over $8 billion in revenue in 2016. Today, about one in three American workers are currently eligible to take part in workplace wellness programs (broadly defined as employer-offered programs to promote health or prevent disease). Despite rapid growth in this industry, the effects of these programs on employee health, well-being, and total medical expenditures remain unclear.

Context of the evaluation

The study took place at the University of Illinois at Urbana-Champaign. Partnering closely with the university, researchers designed and implemented a comprehensive workplace wellness program called “iThrive.” All benefits-eligible employees were invited to participate in the study. iThrive consisted of an on-site biometric screening, online health risk assessment, and a variety of wellness activities, such as smoking cessation programs and recreational athletic classes.


Details of the intervention

Researchers conducted a randomized evaluation to test the impact of the iThrive workplace wellness program on a variety of health behavior, productivity, and cost measures. Researchers invited 12,459 benefits-eligible university employees to participate; interested employees were required to complete a 15-minute online survey covering topics such as health status, health care utilization, job satisfaction, and productivity. Of the 4,834 employees (38.8 percent) who completed the survey, 3,300 employees were randomly assigned to one of six treatment groups, while the other 1,534 employees were assigned to a control group. Those in the treatment groups received access to all iThrive programming. In the first year, the six different treatment groups were offered varying levels of financial incentives to participate in the program (from $50 to $350).1 Members of the control group did not have access to any iThrive programming, but were offered a follow-up health screening one and two years after iThrive was first implemented.

For each year of the two-year program, participants were invited to complete a biometric health screening and an online health risk assessment. Participants who completed these two steps were invited to enroll in fall and spring semester health and wellness activities, such as in-person classes about chronic disease management and weight management; physical fitness classes; a tobacco cessation hotline; and an online, self-paced wellness challenge.

Results and policy lessons

The iThrive workplace wellness program changed health beliefs, beliefs about management, and some self-reported outcomes, but it had no effect on biometrics like weight or blood pressure; medical diagnoses; medical utilization; medical spending; or employment outcomes like absenteeism or productivity.

Effects in Year 1

After the first year of the program, employees invited to participate in iThrive reported increased health screenings and more favorable views of management but did not demonstrate other changes on 40 other productivity, behavior, and health outcomes. Employees who were invited to participate in iThrive were 4 percentage points more likely to report that they had ever received a health screening, from a baseline mean of 94 percent (a 4.2 percent increase). After the first year of participating in iThrive, employees were 5.7 percentage points more likely to believe that management prioritized their health and safety, from a baseline mean of 79 percent (a 7.2 percent increase).2

Effects on health beliefs and self-reported outcomes in Year 2

After the second year, the workplace wellness program improved employee beliefs about their own health and self-reported health outcomes. Employees who participated in iThrive believed that they had lower chances of poor health, as measured through beliefs about their BMI, cholesterol, blood pressure, and glucose. Those who participated in iThrive were also 6.1 percentage points more likely to report that they had a primary care physician, from a baseline mean of 86.1 percent (a 7.1 percent increase). 

Effects on clinical, medical spending, and employment outcomes in Year 2

Despite these perceived changes, iThrive had no effect on employee biometric measures, medical diagnoses, or medical utilization over the two years of the program. Participation in the program did not impact the measured biometric, medical utilization, or medical spending outcomes, demonstrating a mismatch between employee perceptions of their health and actual measures of their health. These results largely persisted over two years of the program.

Effects of incentives on participation

The study also indicated that financial incentives may have some impact on workplace wellness participation, but only up to a point. A financial incentive of $100 (compared to $0) boosted participation in the biometric health screening from 47 percent to 59 percent (a twelve-percentage point increase). Doubling the reward to $200, however, only raised health screening completion rates by 4 percentage points (from 59 percent to 63 percent), indicating that there may be diminishing returns to incentivizing participation.

Policy implications

Among those offered the program, healthier employees enrolled in the program at higher rates. This is evidence of positive selection: employees who participated in the workplace wellness program had lower health costs and higher participation in healthy activities when the study began. This suggests that employers could still save on health care costs if the workplace wellness programs enable a company to attract or retain healthier, lower-cost employees. Conversely, workplace wellness programs may shift costs onto employees with lower incomes and with high health care spending and poor health. Ultimately, the study adds to a growing body of evidence from randomized evaluations that workplace wellness programs are unlikely to significantly improve employee health or reduce medical utilization in the short term.

In the second year, study participants were offered smaller incentives – a design choice influenced by budget constraints and the diminishing effect of incentives observed during the first year.
There was no detectable impact on this measure after the second year of the program.