Patients given medication samples are more likely to take their medication than those given prescriptions to fill. The study that produced this finding, reported in the June issue of APA’s Psychiatric Services, also found that a significant number of patients were noncompliant with their medication regimen in the first week, according to Leo Bastiaens, M.D., the lead investigator.

"I know from the literature that medication compliance is very poor in medicine in general; however, no one had ever studied compliance after one week. Specifically, 31.5 percent of those receiving prescriptions and 13 percent of those receiving samples were not 100 percent compliant, and this is consistent with the literature that studied compliance after a longer period of time. Our findings suggest that noncompliance probably starts in the first week," said Bastiaens, who along with coinvestigators Salim Chowdhury, M.D., and Larry Gitelman, R.N., C.R.N.P., works at St. Francis Medical Center in Pittsburgh. Bastiaens is director of the assessment and brief intervention service at the medical center.

Besides being the first investigators to study compliance one week after beginning a medication regimen, they also are the first comparing how patients’ compliance is affected by the use of samples versus prescriptions, explained Bastiaens.

The subjects, 140 patients aged 18 and older, required medication for their mild-to-moderate depression and/or mild-to-moderate anxiety disorder. The subjects had visited the center’s emergency room seeking a psychiatric evaluation between May 1998 and April 1999, and during their visit of less than two hours, they were evaluated by Bastiaens and Chowdhury, both of whom are psychiatrists.

The investigators randomly gave half of the subjects prescriptions and half samples of SSRIs, other antidepressants, or benzodiazepines. To prevent bias they were not told about the study. The patients had not taken any psychotropic medication for at least a month.

After one week, Gitelman, a nurse practitioner, called the patients at home to conduct a brief telephone interview. He was able to reach 108 subjects, 54 of whom had received samples and an equal number who had been given prescriptions. Gitelman determined whether the patients had taken their medication every day (100 percent compliance), one time or several times (1 percent to 99 percent compliance), or not at all.

The researchers found that 87 percent of those who were given samples had taken their medication every day, compared with 68.5 percent of those who had received prescriptions, a statistically significant difference.

There was, however, no statistically significant difference between the sample group and the prescription group in the percentage of patients who were compliant when the researchers assessed those who took the medication once or several times and those who did not take any of their medication. Therefore, when considering all these levels of medication compliance together, "the groups didn’t separate out very well," said Bastiaens.

"Psychiatrists should expect 100 percent compliance for the first week; however, we found that even of those who received the samples, only 87 percent were compliant. This shows that there is a tremendous drop off in compliance even in the first week."

When asked what led him to study this issue, Bastiaens replied, "We give samples quite frequently here, and thus we think intuitively that compliance would be better with samples. However, we asked ourselves whether there is any evidence of this."

When the researchers found no relevant literature, they designed their study and found that there was some advantage in handing out samples.

Bastiaens noted that he and his colleagues limited the study to those with depression and anxiety disorder because if they had included other illnesses, "the sample would be too heterogeneous in terms of a clinical population."