While policymakers debate complex changes to reduce health spending, promoting patients’ involvement in treatment decisions could have an immediate effect. A new Health Affairs report about decision aids — materials given to patients to help educate them about treatment options — shows they can help hold down costs by reducing demand for medical procedures.

“The decision aids discuss all the available treatment options equally,” said Dr. David Arterburn, an author of the study released Tuesday and an investigator at Group Health Cooperative, a non-profit health system in Seattle. For example, in the aids for joint disorders, he said, “Losing weight and increasing physical activity are discussed in detail, as are anti-inflammatory medications, other over the counter medications, and prescription medications for treating osteoarthritis.”

Decision aids can be used for a variety of medical issues, from cardiovascular health to hip replacements. They are delivered in the form of DVDs or printed guides, and are usually provided before a patient visits a specialist.

Researchers conducted randomized trials in Washington state with patients who suffered from knee and hip osteoarthritis, the most common joint disorders in the U.S. They sent aids to 332 patients with hip osteoarthritis and 978 to patients with knee osteoarthritis. The treatments and outcomes were then tracked and compared to a control group that did not receive the aids.

After six months, researchers found that among patients with knee problems who received aids, 38 percent fewer chose to have elective knee replacement surgery than the control group. Among patients with hip problems, 26 percent fewer opted for hip replacement surgery. Patients who received aids also had slightly fewer visits to primary care and specialty care doctors.

Overall treatment costs were lower among patients who received aids. For those with hip osteoarthritis, the average total cost of treatment was $13,489 after the use of decision aids, compared to $16,557 for the control group. In the knee osteoarthritis groups those with aids spent $8,041 compared to $10,040 in the control group.

Many states see promise in the shared decision model, and are taking early steps to encourage its use.  Minnesota, for example, outlines the need for a physician to discuss health care options in a shared decision making process in its rules for medical homes.