Participating in the decisions concerning their own health makes patients happier, but it could also up their hospital bill, a new study finds. According to research published online in the Journal of the American Medical Association (JAMA), patient participation in medical decision making is associated with longer hospital stays and higher medical costs.

An increasing number of professional medical associations are encouraging doctors to let patients have a more active role in making health decisions, and there is evidence to suggest patients are more satisfied and have improved health outcomes when they do take an active hand in helping to make decisions about their health, the authors wrote. But there is little data on how that shared decision making affects the utilization of resources.

For this investigation, the team conducted a survey of 21,754 patients admitted to the University of Chicago Medical Center general internal medicine service between 2003 and 2011, asking questions about patient preference on receiving medical information and participating in decision making. The survey questions were linked with administrative data from the hospital, including how long each patient stayed and how much the services cost.

The researchers found that while 96.3 percent of patients wanted to receive medical information, only 28.9 percent wanted to participate in the medical decision making. Those who wanted a hand in making decisions were better educated and had better private health insurance than those that preferred to leave the decisions to their doctors. However, the team said, patients who wanted to participate in their health decisions also had a 0.26-day longer length of hospitalization, and $865 more in costs.

"Patient preference to participate in decision making concerning their care may be associated with increased resource utilization among hospitalized patients," the researchers wrote. "Variation in patient preference to participate in medical decision making and its effects on costs and outcomes in the presence of varying physician incentives deserve further examination."

In their study, reports HealthDay, the researchers calculated that if 30 percent of the 35 million patients hospitalized each year in the U.S. shared in the medical decision making with their doctors, that would add about $8.7 billion to the cost of medical care each year.

The study's results run counter to "the result that everyone would have liked -- that patients who are more engaged in their care do better and cost less," said University of Chicago professor and study author David Meltzer in a university press release. "Patients who want to be more involved do not have lower costs. Patients, as consumers, may value elements of care that the health care system might not."

Although patients should be more involved in their health, he added, "We need to find ways to create functional doctor-patient partnerships that lead to good health as well as sound decisions about resource utilization."

Source: Tak HJ, Ruhnke GW, Meltzer DO. Association of Patient Preferences for Participation in Decision Making With Length of Stay and Costs Among Hospitalized Patients. JAMA. 2013.