Humana Inc. employees engaged in the health insurer's HumanaVitality wellness and rewards program over a three-year period had fewer absences from work, lower health claims costs and fewer hospital and emergency room visits than employees who didn't participate, the health insurer said Tuesday.

Health claims costs for Louisville, Kentucky-based Humana's workers who engaged in the program decreased 6% in the first year of the program and 10% by the third year, compared with 2010, before HumanaVitality was launched, Humana said in a statement announcing the results of a study of more than 8,000 Humana employees enrolled in the wellness program from July 2011 to June 2014.

Meanwhile, health claims costs for unengaged workers increased 17% by the third year of the program, Humana said.

Additionally, workers who engaged in the wellness program had six fewer hours of unscheduled absences compared with unengaged members, who averaged 23 hours of unscheduled absences per year, according to the study.

And unengaged workers had 56% more emergency room visits and 37% more hospital visits than engaged workers, Humana found.

The study also found that the percentage of engaged workers in a low-risk range for chronic conditions increased by 24.4% over the three-year period as they moved from higher-risk categories, compared with 14% for unengaged workers, Humana said.

Humana counts engaged employees as those who went beyond the initial health assessment to set health goals and take steps toward meeting them, while unengaged employees either didn't participate in the wellness program or did no more than take the health assessment, said HumanaVitality President Joe Woods, based in Chicago.

Employees participating in the HumanaVitality program are rewarded points for both taking steps to lead healthier lives and meeting health goals. Employees can achieve points by taking a health assessment, going to the doctor for preventive screenings, hitting the gym or running a 5K race, or even taking educational classes on nutrition or weight loss, Mr. Woods said.

Families can also get points by getting immunizations for their children, getting CPR-certified or donating blood, he said.

The points can then be redeemed for gift cards, fitness equipment and personal electronics, or the points can be used to make charitable donations.

“HumanaVitality is deeply rooted in behavioral economics and actuarial science,” Mr. Woods said of what makes the program successful. That foundation “motivates people to take steps to improve their behaviors.”

But he also said that “employers that have a culture of wellness” at work also have an easier time at finding success in wellness programs. “Wellness needs to become a part of the way you live your life every day,” he said.

Engagement results for the first external population of HumanaVitality members to reach the actuarially significant three-year membership mark will be included in next year's impact analysis, Humana said in a statement.