Workplace wellness programs don’t provide employees with significant measurable outcomes, according to a new study published in the Journal of the American Medical Association.

The study, which looked at 33,000 employees at 160 BJ’s Wholesale Club Holdings Inc. worksites for a year and a half, found about 4,000 staff participated in the company’s wellness program. It comprised eight modules on nutrition, physical activity, stress reduction and related topics implemented by registered dieticians.

The study assessed four outcomes: self-reported health and behaviours through surveys; clinical measures of health via screenings; health-care spending and utilization; and employment outcomes from administrative data.

Read: 71% of global employers offer wellness programs: survey

The U.S. retail company’s worksites with a wellness program had an 8.3 percentage point higher rate of employees who reported engaging in regular exercise and a 13.6 percentage point higher rate of workers who reported actively managing their weight. However, after 18 months, the study found no significant differences in other self-reported health and behaviours, clinical markers of health, health-care spending or utilization, absenteeism or job performance.

“Employees exposed to a workplace wellness program reported significantly greater rates of some positive health behaviours compared with those who were not exposed, but there were no significant effects on clinical measures of health, health-care spending and utilization or employment outcomes after 18 months,” noted the study.

Among the 33,000 employees, the mean participation rate in surveys and screenings at intervention sites was between 36.2 per cent and 44.6 per cent. At primary control sites, the percentage dropped slightly, to between 34.4 per cent and 43 per cent. The study also found the rates for two self-reported outcomes were higher in the intervention group than in the control group: for engaging in regular exercise (69.8 per cent versus 61.9 per cent) and for actively managing weight (69.2 per cent versus 54.7 per cent).

Read: Look and measure before leaping into a workplace wellness program

As well, it found the wellness program had no significant effects on other pre-specified outcomes: 27 self-reported health outcomes and behaviours, including self-reported health, sleep quality and food choices; 10 clinical markers of health, including cholesterol, blood pressure and body mass index; 38 medical and pharmaceutical spending and utilization measures; and three employment outcomes: absenteeism, job tenure and job performance.

“Although limited by incomplete data on some outcomes, these findings may temper expectations about the financial return on investment that wellness programs can deliver in the short term,” stated the study.