Characteristics of patients receiving pharmaceutical samples and association between sample receipt and out-of-pocket prescription costs

Background: Pharmaceutical samples are widely used for promotion and marketing, yet little is known about who receives samples or how their use is associated with patient's prescription costs. Objective: To examine the characteristics of those receiving samples and the relationship between sample receipt and out-of-pocket prescription costs. Design, Subjects, and Measures: We divided the 2002-2003 Medical Expenditure Panel Survey, a nationally representative, panel-design longitudinal study, into baseline and analysis periods. We conducted logistic and generalized linear regression analysis of 5709 individuals in the analysis period who did not receive samples during the baseline period. The primary outcome measures were sample receipt and prescription expenditures. Results: Fourteen percent of individuals received at least 1 sample during the analysis period. On multivariate analyses sample receipt was greater among those who were younger and those not on Medicaid. In generalized linear regressions controlling for demographic characteristics and health care utilization, the predicted 180-day out-of-pocket prescription expenditures were $178 [standard error (SE), $3.9] for those never receiving samples. Among those receiving samples, the corresponding out-of-pocket expenditures were $166 (SE, $8.9) for periods before sample receipt (P = 0.16 for comparison with those not receiving samples), $244 (SE, $9.2) for periods during sample receipt (P < 0.001 for comparison with periods before sample receipt) and $212 (SE, $12.4) for periods following sample receipt (P = 0.008 for comparison with periods before sample receipt). Results were qualitatively similar when total prescription costs were examined. Conclusions: Individuals receiving samples have higher prescription expenditures than their counterparts. These findings suggest that sample recipients remain disproportionately burdened by prescription costs even after sample receipt.