WellPoint Inc. (WLP) employees will have a personal stake in the health of the company's customers, thanks to a new plan that ties a portion of their annual bonuses to it.

The nation's largest health insurer unveiled a plan Tuesday to link 5 percent of every annual bonus to a new measurement called the Member Health Index.

The index will monitor 20 different clinical areas to determine whether patient care is improving.

It aims to take measurements from broad categories like patient safety or care management and tell whether care has improved for most patients, but especially those dealing with chronic conditions like diabetes, asthma or high blood pressure, said Dr. Sam Nussbaum, WellPoint's executive vice president and chief medical officer.

If the index reaches an improvement goal set by the company, WellPoint's roughly 42,000 employees will see the result in their bonus check. The new measurement affects every employee from the executive suite on down, Nussbaum said.

"It's basically all or nothing for our company this year," he said. "We're either going to achieve it or we're not going to achieve it."

Linking employee bonuses to care improvements will "get everyone energized about improving health care in our company," he added.

Consultant Bob Boyer said he knows of no other insurer that links employee bonuses to the health of its customers.

The program shows WellPoint is making "a concerted effort to show that they've got some skin in the game, when it comes to their members' health," said Boyer, market business leader for the Indianapolis office of Mercer Health and Benefits.

"That might be the next evolution in measuring member health," he said. "I think it's an innovative approach."