Impact of Workplace Wellness on Health, Health Care, and Employment Outcomes After 3 Years: A Randomized Controlled Trial

Over 80% of large employers in the U.S. offer a workplace wellness program, which has grown to over an $8 billion industry. Despite the increasing prevalence of wellness programs, supported by both private and public investments such as the Affordable Care Act, rigorous evidence on the causal effects of wellness programs on health and economic outcomes remains scant.

We conducted a randomized controlled trial of a longitudinal workplace wellness program at a large U.S. employer across 160 worksites along the Eastern U.S. in partnership with a wellness vendor. Randomization was at the worksite level, with 25 worksites randomly selected to receive the intervention. This design allowed us to capture the effects of an intervention aiming to affect workplace culture and utilizing group as well as individual programming.

Spanning about 3 years from 2015 through 2017, the workplace wellness intervention comprised 12 modules focusing on areas of wellness such as physical activity, healthy eating, and stress reduction, with financial incentives for participation. We studied outcomes across a wide range of domains, including health behaviors, health care spending and utilization, self-reported and clinical health outcomes, and employment outcomes. Biometric data and survey responses were collected in person at the 25 intervention sites and at 25 randomly selected control sites, and administrative data on employment outcomes and health insurance claims were collected across all 160 worksites, with a total sample size of more than 50,000 employees.

This paper reports results at the end of the 3 years of wellness programming. Interim results at the 1.5 year mark suggested that the intervention had increased the proportion of employees who reported engaging in regular exercise and actively managing their weight, but at that point had no significant effects on clinical markers of physical or mental health; spending or utilization; or absenteeism, job tenure, or job performance. This follow-up post-intervention analysis assesses the full range of outcomes, including pre-specified subgroup analyses. The results of this rare randomized controlled evaluation of an increasingly prevalent but poorly assessed workplace intervention will have the potential to inform both public policy and private investments.