Following free drug sample receipt, patients who receive these samples have significantly higher out-of-pocket prescription costs than those who don't, according to the first study to look at the out-of-pocket cost associated with free-sample use, published in the March 24, 2008, issue of Medical Care.
Patients who never received samples had estimated out-of-pocket prescription costs of $178 over six months. Patients who received samples spent an estimated $166 for a six-month period prior to getting free samples, $244 for the six months in which they received samples and $212 for the six-month period following sample receipt.
"Our findings suggest that physicians should use caution in assuming that the use of free samples ultimately reduces patients' out-of-pocket prescription cost," said study author G. Caleb Alexander, MD, assistant professor of medicine at the University of Chicago Medical Center.
There has been widespread debate about the advantages and disadvantages of free samples. In 2006, the New York Times published a letter to the editor from Ken Johnson, senior vice president of the Pharmaceutical Research and Manufacturers of America. He argued that "many uninsured and low-income patients benefit from these free samples, which often serve as a safety net."
"Samples may be particularly valuable in providing patients economic relief when they are used short-term and not followed-up with long-term prescription for the same medicine," says Alexander. "However, all too often, physicians and patients end up continuing the medicines initially begun as samples, even though older, less expensive alternatives may exist."
Previous surveys have found that free samples can lead to overuse of newer drugs over their older counterparts, but these prior studies have usually examined just one clinical setting and have not examined the costs associated with sample receipt.
"We believe our study is one of the first to look at the economic consequences of sample receipt," Alexander said.
His team used the Medical Expenditure Panel Survey, conducted by the Agency for Healthcare Research and Quality, to examine the characteristics of those receiving samples, as well the relationship between sample receipt and out-of-pocket prescription costs.
They followed 5,709 patients from the national survey for up to two years. The mean age of patients was 48 years, 84 percent were white and 76 percent had private insurance. Fourteen percent of patients received at least one sample, with a total of 2,343 samples dispensed during the analysis period.
The authors found that there were important differences in the characteristics of patients who received samples and those who did not. The odds of sample receipt were lower among those who were older and also among those who had Medicaid as their source of insurance coverage.
The study was not designed to identify the exact reason that sample users have higher prescription costs after sample receipt. However, the authors hypothesize two main possibilities for this surprising finding.
First, those who received samples may have been more seriously ill than those who did not. But underlying health status, say the authors, explains only a part of the difference in out-of-pocket costs.
Equally important, they suggest, is that patients who receive free samples may end up paying for a prescription for the medicine initially begun as a free samples. The medicines that are given as free samples are often the newest and the most expensive.
"Regardless of the degree to which these different mechanisms account for our findings," Alexander said, "patients and physicians should consider complementary ways to reduce patients' burden from out-of-pocket prescription costs, such as using more generic medicines, stopping non-essential treatments, and using three-month rather than one-month supplies."
For policy-makers and researchers, their findings provide an opportunity to consider the complexity of issues raised by sample use.
"Further research is needed to examine patient-physician communication about samples," suggests Alexander, "as well as how physicians decide who needs samples and how samples are distributed across different types of physician practices."
They are also continuing studies that look the economic consequences of other common prescribing decisions that physicians and patients face.
The study was supported by the Robert Wood Johnson Foundation. Additional authors of the paper include James Zhang from Virginia Commonwealth University and Anirban Basu from the University of Chicago.