Higher insulin expenditures associated with utilization of free medication samples

Insulin prescription prices have been a barometer of the complexities and concerns in the United States drug supply chain. The influence of free samples of medications have not been explored in this context.

To examine the trends in insulin prescription prices among sample users and non-users.

Medical Expenditure Panel Survey (MEPS) data from the years 2009-2015 were used. Insulin users were identified and grouped according to self-reported sample use and as new users based on year of treatment initiation variables. Prevalence of sample use was discerned using Cochran-Armitage Trend tests. Per prescription costs were summed as both the total costs and the patient out-of-pocket costs (OOP) and compared between users and non-users of samples. MEPS weights were used to create a nationally representative analytic sample.

The weighted analytic sample included 5.3 million insulin users in 2009, which increased to 7.7 million insulin users in 2015. Among these, 5.6% reported sample use in 2009, which peaked in 2014 (8.1%), and was 6.2% in 2015 (p < 0.001). In 2015, the average OOP and overall costs were higher for sample users vs. non-users ($232 vs. $108, P < 0.001). This pattern was consistent each year. Per prescription costs per insulin prescription increased by 62% between 2009 and 2015 for sample users ($232 vs. $143, p < 0.001) and increased 35% for non-users ($108 vs. $80, p < 0.001).

Sample use has increased among insulin users and is associated with higher per prescription costs. Patients and prescribers should consider the implications of sample use in the long-term.