By MATTHEW PERRONE

AP Health Writer

WASHINGTON (AP) _ When many of us have a medical appointment we’re concerned about our finances: how much will we owe out-of-pocket? What’s our co-pay? But next time, you may also want to ask your doctors about their financial situation.

That’s because nearly 95 percent of U.S. physicians accept gifts, meals, payments, travel and other services from companies that make the drugs and medical products they prescribe, according to the New England Journal of Medicine. This has been a common practice for decades and studies show it affects doctors’ prescribing decisions. But for the first time, patients will soon be able draw back the curtain.

Starting in September the federal government will make available an exhaustive online database of payments to U.S. physicians and hospitals, under a section of the health care overhaul passed in 2010. The measure, known as the Sunshine Act, requires most makers of drugs and medical supplies to report all payments, gifts and other services worth $10 or more that they provide to health professionals.

“I think every patient out there should know who actually is paying their doctor,” says Paul Thacker, a fellow at Harvard University’s Safra Center for Ethics. “The one thing we know is that money changes behavior and people tend to respond to who is giving them money.”

As a Senate staffer, Thacker helped craft the disclosure rules, which are designed to lay bare the industry practice of “detailing,” in which company sales people court doctors with everything from pens and mugs to lucrative speaking engagements. Pharmaceutical companies spend an estimated $20.4 billion on these activities each year and then track doctors’ prescribing patterns to gauge the return on their investment.

Using a federal website, patients will be able to search most payments made to their health care provider, from $20 lunch bills to hundreds of thousands of dollars in consulting fees. Some of this information has already come to light, mainly due to legal settlements that required drugmakers to disclose the information.

Websites like Dollars for Docs, from the nonprofit journalism group ProPublica, pool this data together and enable users to search doctors by name to see what payments they’ve received. The database covers 15 pharmaceutical companies, including Pfizer Inc. and Johnsons & Johnson, and begins with payments made in 2009.

But how is a layperson to make sense of it all? And how does one separate common medical practice from truly questionable activity?

Dr. Leana Wen of the George Washington University says she simply groups all payments into two categories: research and everything else.

Most studies on new drugs and devices are funded by companies, which partner with physicians to enroll patients and track their response to the treatment. Wen and others say these partnerships are a necessary part of clinical research and are common at leading medical centers. But she says virtually all other payments are problematic.

“If someone gets significant consulting fees or speaking fees, I would be more concerned about that because they are doing something that has been shown in studies to change their prescribing habits,” said Wen, who teaches at the university’s emergency medicine department.

An analysis of 29 studies published by the Journal of the American Medical Association in 2000 found that doctors who accept fees, meals and other perks from drugmakers are more likely to prescribe their brand of drugs. This can negatively impact patients because the medicines promoted by drugmakers are usually newer, more expensive and potentially less safe than older medicines. Another 2012 study published in JAMA found that one in five new prescription drugs introduced between 1995 and 2005 were linked to unforeseen side effects after they reached the market.

Even with all the new information coming online this fall, the Sunshine Act will not capture all the financial forces that motivate physicians. For instance, many interventional cardiologists are paid for each procedure they perform, such as implanting stents that prop open clogged arteries. The more stents cardiologists implant, the more they are paid.

Wen says patients should know whether their doctor is being paid based on a fixed salary or a per procedure rate. About 100 doctors disclose this information and other financial details on a website Wen created, whosmydoctor.com, which advocates “total transparency” for medical professionals.

Although patients will benefit from increased transparency in coming years, the ultimate goal of policymakers is to pressure doctors to give up some of their more egregious relationships with industry. It’s too early to tell whether those ties will be weakened, but supporters of the Sunshine Act are encouraged by early reactions from their colleagues.

“Some of them are now saying, `It’s just as easy for me to buy my own lunch, I don’t need drug company people coming in and doing that,”’ said Dr. Stephen Smith, professor emeritus at Brown University.