MONDAY, March 24 (HealthDay News) -- Patients who receive free drug samples from their doctors end up having significantly higher out-of-pocket costs for their prescription drugs than people who don't receive free samples, a new study finds.

In fact, patients who received free samples spent about $166 in out-of-pocket costs on prescription drugs in the six months before receiving the samples, $244 for the six months in which they received samples, and $212 for the six months following receipt of the free drugs, the study found.

But patients who didn't get free samples spent about $178 on prescription drugs over six months.

"This is a curious finding because one would think, intuitively, that if you receive a free sample, one's out-of-pocket prescription cost would be lower, not higher," said lead researcher Dr. G. Caleb Alexander, an assistant professor of medicine at the University of Chicago Medical Center.

There are several possible explanations for the finding, Alexander said. One is that patients who receive free samples may be sicker than patients who don't get samples.

"The second possibility is that patients who receive free samples may go on to receive and fill prescriptions for the very same medicine that were initially begun as free samples," Alexander said. "We know that drugs that are available as free samples are those that are being widely marketed and promoted and these drugs are more expensive than their older, less promoted counterparts."

The study findings are published in the March 24 issue of the journal Medical Care.

For the study, Alexander's team collected data on 5,709 patients who had participated in the Medical Expenditure Panel Survey. The survey was done by the U.S. Agency for Healthcare Research and Quality and the patients were followed for up to two years.

Seventy-six percent of the patients had private health insurance. During the study period, 14 percent of them were given at least one drug sample. A total of 2,343 samples were distributed during the period, the researchers found.

Patients who received free samples were more likely to be younger and have private insurance, while patients with Medicaid were less likely to receive samples, the researchers noted.

The findings follow earlier research, reported in the February issue of the American Journal of Public Health, in which Harvard University researchers showed that more than 80 percent of free drug samples were given to wealthy and insured patients, not to uninsured and poorer patients.

Alexander said there are many ways doctors and patients can work together to reduce drug costs, but giving away free samples may not be the best one.

"Doctors and patients both should be encouraged to consider alternative ways to reduce patients' out-of-pocket costs," he said. "There are many other strategies doctors can use, such as prescribing a three-month rather than a one-month supply, such as using greater numbers of generic medicines, and discontinuing non-essential medicines."

Dr. David Katz, director of the Yale University School of Medicine's Prevention Research Center, said free samples aren't designed to help lower drug costs, but rather to sell newer and more expensive drugs.

"Almost every clinician's office is stocked with drug samples," he said. "For patients and providers alike, these free drugs can take on the aura of Halloween goodies. Passing them out feels like giving a gift."

But, Katz added, "free samples are by no means a long-term solution to high prescription drug costs. Rather, they are at least, in part, a marketing device, a chance to sample the wares."

The pharmaceutical industry had this to say: "Free pharmaceutical samples are beneficial to patients of all income levels. Patients are able to try out a new therapy - gaining valuable first-hand experience of its benefits and side effects - without making a co-payment," said Pharmaceutical Research and Manufacturers of America (PhRMA) senior vice president Ken Johnson.

"What's more, contrary to statements made by critics, America's physicians prescribe medicines based on a wide range of factors, not simply receipt of free prescription drug samples," Johnson added in a prepared statement.

More information

For more on prescription drug trends, visit the Kaiser Family Foundation.