The public's faith in President Barack Obama's plan for health care reform is fading. Proposals ranging from the public insurance option to reimbursing physicians for end-of-life counseling are mired in a debate that's as overheated as August temperatures. Even the seemingly self-evident idea that the nation has a moral duty to make sure all citizens have basic access to health care is up for grabs. But there's one aspect of health care reform that California voters support almost universally: better medical evidence.

A poll released Sept. 2 shows extraordinary levels of enthusiasm for policies that would help doctors and patients know what works in medicine, what doesn't work and for which patients. In a poll of 800 California voters conducted by Lake Research, 88 percent of respondents said they believe it is important that doctors have access to scientific evidence that compares the effectiveness of different treatments. Nearly half, 46 percent, consider it extremely important.

Of course they do. Patients go to the doctor looking for effective treatment, and this being the 21st century, they assume that their doctors' recommendations will be based on up-to-date science.

Yet all too often that's not the case. According to the prestigious Institute of Medicine, only about half of the treatments, surgeries, tests and minor procedures that doctors recommend are backed up with sound medical evidence. The other half? Doctors have only theory, tradition or marketing by the pharmaceutical and medical device industries to guide them.

This lack of valid science hurts patients and costs the nation billions in wasted dollars annually. Take lumbar fusion surgery for simple lower back pain – pain that isn't caused by cancer or a major accident. Between 1993 and 2003, spending for lumbar fusion rose 500 percent, despite an almost complete lack of sound evidence that this invasive, potentially risky procedure is effective. It might relieve pain for some patients – and worsen it for others. Surgeons and patients simply don't have the information they need to predict ahead of time who is likely to benefit and who will be harmed.

Many, if not most, patients are also in the dark about the very real dangers posed by any hospitalization. Out of the 34 million patients admitted to the hospital each year in the United States, as many as 190,000 die not from their disease but from infections acquired in the hospital or avoidable medical errors. Poor-quality medical care kills more people than AIDS, breast cancer and car accidents combined.

On the flip side, there is inappropriate undertreatment. Even when sound evidence exists, patients don't always get the care they need. About 25 percent of heart attack patients don't receive an aspirin and beta blocker within 24 hours of being admitted to the hospital, despite solid science showing that these drugs can cut the risk of a subsequent heart attack by 20 percent.

The same is true for countless other conditions and tests. In some cases, the root cause is poorly trained doctors, but most of the time, we just don't have effective ways of monitoring quality and providing doctors with timely, reliable evidence.

Voters know that getting care they don't need, and not getting care they do, is bad for their health. According to the poll, 80 percent of voters think it is a serious problem when doctors provide unneeded medical treatments, and 79 percent think it's a serious problem when they don't get needed care. Ninety percent think doctors should be required to tell their patients when there is no scientific evidence to support a treatment recommendation.

Why isn't the issue of medical evidence front and center in the health care debate? Maybe because doctors have not always been truthful in telling people what they know and don't know. Many physicians are either unwilling or unable to take the time needed to fully explain where uncertainty exists. As a result, 65 percent of California voters are under the mistaken impression that most or nearly all of the health care they receive is backed up by scientific studies.

The results of this poll, which was conducted for the Campaign for Effective Patient Care, a nonprofit founded this year with initial support from AARP, California Association of Physician Groups and Blue Shield of California, should embolden legislators and policymakers to forge ahead with legislation that supports medical research aimed at providing practical answers to everyday medical dilemmas. Two of the three health care reform bills wending their way through Congress contain provisions for research that compares the effectiveness of different treatments. The bills would also reinforce the infrastructure that's needed to disseminate results to both doctors and patients.

There's a lot of misinformation being circulated by opponents of comparative effectiveness research. Some are politically motivated and simply want to see Obama and the Democrats fail. Others have a financial interest in keeping patients and doctors in the dark. Either way, Americans deserve better quality health care, and voters know that the only way to get there is through better medical evidence.

Shannon Brownlee is a senior research fellow at the New America Foundation, a nonpartisan thinktank based in Washington, D.C. Dr. Michael Wilkes is the director of global health at the University of California, Davis.