Group Health Cooperative has driven down the costs of caring for osteo-arthritis patients with a relatively simple tool: video-based decision aids.

After the Seattle-based health system introduced decision aids, patients opting for knee replacements fell by 38 percent and those choosing to go ahead with a hip replacement fell by 26 percent. What's more: the cost of caring for those patients dropped by 12 to 21 percent, depending on the location, over six months.

"We were a bit surprised to see such a large change in patient rates of surgery and cost of care," says David Arterburn, M.D., a Group Health internist and researcher. "What it says to us is that this is high-value work."

The Group Health findings provide real-world results that support evidence coming from randomized trials. Taken together, seven trials involving patients facing elective surgeries have suggested that the use of decision aids is associated with 25 percent fewer patients opting for surgery, according to research on the Cochrane Library.

These aids are a key component of shared decision-making. They can be written or electronic, including video, and provide unbiased information about the pros and cons of various options for treating a health condition. That is important, Arterburn says, because frequently a physician's clinical expertise is given more weight in decision-making than a patient's preferences and values.

"A decision aid does not replace the provider," Arterburn says. "It just enhances the conversation by helping to even the playing field between the provider and patient."

In 2009, Group Health began introducing decision aids to patients who face choices about elective surgery in six specialties. As of November 2012, the organization had distributed more than 30,000 aids, earning bragging rights that it has distributed more of them than any other health care organization in the world.

Shared decision-making is gaining momentum as health care leaders look for ways to engage patients and to deliver patient-centered care, says Diana Stilwell, chief production officer at the Informed Medical Decisions Foundation. But many barriers to widespread use of decision aids remain. For example, some providers find it difficult to integrate them into routine practice because the tool must be delivered to the patient at the right time in the decision-making process and in a format that the patient can use.

Stilwell says Group Health's results reflected more than the use of the decision aids themselves. "They pulled all of their surgeons out of their operating rooms for a half-day and sent them to training in shared decision-making, which demonstrated incredible commitment from a leadership standpoint," she says.