The Effect of Providing Free Samples of Generic Cardiovascular Medications to Physicians (SAMPLES)

• Percentage of prescriptions filled for generic medications [ Time Frame: 6 months after receipt of samples ] [ Designated as safety issue: No ]
  
• Patient adherence - Amount of prescriptions actually filled (Proportion of Days Covered) within each class in the first year of use of an anti-hypertensive or lipid-lowering medication [ Time Frame: in the year subsequent to patient initiation of an anti-hypertensive or lipid-lowering medication ] [ Designated as safety issue: No ]
  

• The sum of medication costs for all prescriptions used to treat either hypertension or hypercholesterolemia. [ Time Frame: The year before and the year after provision of samples ] [ Designated as safety issue: No ]
  
• Guideline adherence - Proportion of patients who received first-line anti-hypertensive medications suggested by JNC-VII when medications are initiated. [ Time Frame: In the 6 months after receipt of samples ] [ Designated as safety issue: Yes ]
  

Highly-effective generic cardiovascular medications are frequently underused, leading to greater overall drug costs and cost-related non-adherence. Interventions are needed to stimulate appropriate generic drug use without creating administrative or financial barriers to branded medications that may impede essential medication use.

The SAMPLES trial is a clustered, randomized controlled trial of the effect of providing physicians with free generic samples of hydrochlorothiazide for hypertensive patients and simvastatin for patients with hyperlipidemia. We will randomize 660 primary care physicians in Pennsylvania, clustered by physician practice, to receive free samples for both conditions or to receive no samples. We will use pharmacy claims of their patient population enrolled in a state-sponsored prescription drug assistance program to evaluate outcomes of interest. The primary outcomes are physician prescribing behavior (proportion of prescriptions that are generic), and patient adherence to chronic therapy. Secondary outcomes will include physician adherence to established guidelines (for anti-hypertensive regimens) and overall prescription drug costs. Primary analyses will be based on intention-to-treat principles.

This trial highlights a new and innovative approach to stimulate cost-effective prescribing. Free generic samples can reduce overall drug costs as well as out-of-pocket costs to the patient without sacrificing efficacy, and may result in improved adherence to essential cardiovascular medications. This intervention may also improve adherence to practice guidelines and improve the quality of care received. If found to be effective, this strategy could be utilized broadly by private insurers or government payers aiming to stimulate more cost-effective and higher-quality care.