More than 5.5 million employees at 540 companies across the U.S. are now benefiting from workplace health programs that follow best practices defined by the American Heart Association.

The AHA recognized the companies Tuesday for their efforts in improving workplace health based on a science-based analysis of their health programs. The programs were measured using the AHA’s Workplace Health Achievement Index, which also calculates an average heart-health score for employees.

The American Heart Association created and tested the Index with members of its CEO Roundtable, a leadership collaborative of more than 30 CEOs from some of America’s largest companies committed to improving employee health.

More than 800 companies completed the Index assessment this year, with 67 percent recognized for effectiveness.

“The Index asks companies to be proactive about employee health, benefits, programs and incentives,” said Terry Lundgren, executive chairman of Macy’s Inc. and co-chairman of the CEO Roundtable. “By challenging participating companies to actively prioritize employees’ health and well-being, we can effectively build a culture of health and wellness across America.”

It was the second year of evaluations, which took place from July 1, 2016, to March 31, 2017. The year before, companies were examined during a shorter period of time in a pilot to develop the index. Next year, companies will be evaluated for a full year.

“Our CEO members have collectively pledged to improve the health of our nation’s companies, their employees, and communities,” said Henry Kravis, co-CEO and co-chairman of KKR and co-chairman of the CEO Roundtable. “We’re pleased to see more companies join us on this important mission and help share our collective best practices on workplace health initiatives with all America’s employers.”

AHA CEO Nancy Brown, who leads the CEO Roundtable along with the co-chairmen, said the efforts of these companies are helping to create a “culture of health” that makes healthy choices easier at work and other places people spend their time.

“We know that good health is good business and I congratulate these companies on their successes,” she said.