In what may be the first study of its kind, researchers at Scott & White Health Plan (SWHP) in Temple, Tex., have found a direct relationship between medication sampling and prescribing behavior.
    "For years, our [Pharmacy & Therapeutics] Committee wanted to get samples out of our clinics," said lead author Michael Averitt, DO. "They believed it drove up the cost of drugs, but nobody really knew. Now we know that sampling has a direct impact on prescribing. When samples are available, those are the products prescribers write for."
    Pharmaceutical companies spend about $15 billion annually to distribute drug samples to prescribers, Dr. Averitt reminded the American Academy of Family Physicians Scientific Assembly. More than 90% of physicians have accepted samples at some point in their career.
    "I worked as a detailer before I went to medical school," he continued. "I don't ever remember seeing any data, not even from my drug company, that really showed whether sampling works. Now we know that it does."
    Dr. Averitt compared three SWHP family medicine clinics, which he called X, Y, and Z, with similar patient populations, prescriber panels, and health plan coverage. Only Clinic X accepted and dispensed free drug samples.
    Using 2003 pharmaceutical claims data and sample medication logs from the same period, researchers compared prescribing practices at the physician and clinic level for the 25 sample medications most commonly dispensed. The three clinics used the same formulary.
    During the study period, prescribers at the three clinics wrote more than 144,000 prescriptions costing $6.3 million. The 25 study drugs accounted for 13% of SWHP's total prescription volume and 30% of the drug spending.
    The median cost of a 30-day prescription was $42.90 (range $34.92 to $56.67) at Clinics Y and Z, which did not permit drug sampling. The median cost at Clinic X, which allowed sampling, was over $82.
    Looking at total Rx volume, the 25 sampled drugs accounted for 47.57% of total prescriptions written at Clinic X compared to 39.39% at Clinic Y and 41.58% at Clinic Z.
    "There is a strong correlation between samples and prescribing behavior," Dr. Averitt concluded. "This finding is a strong indication that we need more research into the impact of sampling and consideration of the practice by the profession itself."