Law Michael R, Soumerai Stephen B, Adams Alyce S, Majumdar Sumit R
Centre for Health Services and Policy Research, The University of British Columbia, 201-2206 East Mall, Vancouver, BC V6T 1Z3, Canada.
Arch Intern Med. 2009 Nov 23;169(21):1969-74. doi: 10.1001/archinternmed.2009.320.
Direct-to-consumer advertising (DTCA) is assumed to be a major driver of rising pharmaceutical costs. Yet, research on how it affects costs is limited. Therefore, we studied clopidogrel, a commonly used and heavily marketed antiplatelet agent, which was first sold in 1998 and first direct-to-consumer advertised in 2001.
We examined pharmacy data from 27 Medicaid programs from 1999 through 2005. We used interrupted time series analysis to analyze changes in the number of units dispensed, cost per unit dispensed, and total pharmacy expenditures after DTCA initiation.
In 1999 and 2000, there was no DTCA for clopidogrel; from 2001 through 2005, DTCA spending exceeded $350 million. Direct-to-consumer advertising did not change the preexisting trend in the number of clopidogrel units dispensed per 1000 enrollees (P = .10). However, there was a sudden and sustained increase in cost per unit of $0.40 after DTCA initiation (95% confidence interval, $0.31-$0.49; P < .001), leading to an additional $40.58 of pharmacy costs per 1000 enrollees per quarter thereafter (95% confidence interval, $22.61-$58.56; P < .001). Overall, this change resulted in an additional $207 million in total pharmacy expenditures.
Direct-to-consumer advertising was not associated with an increase in clopidogrel use over and above preexisting trends. However, Medicaid pharmacy expenditures increased substantially after the initiation of DTCA because of a concomitant increase in the cost per unit. If drug price increases after DTCA initiation are common, there are important implications for payers and for policy makers in the United States and elsewhere.
面向消费者的直接广告宣传（DTCA）被认为是药品成本上升的主要推动因素。然而，关于其如何影响成本的研究有限。因此，我们研究了氯吡格雷，一种常用且大量进行市场推广的抗血小板药物，该药于1998年首次上市，并于2001年首次开展面向消费者的广告宣传。
我们研究了1999年至2005年27个医疗补助计划的药房数据。我们采用间断时间序列分析，以分析在开展DTCA宣传后，药品配给量、单位配给成本以及药房总支出的变化情况。
1999年和2000年，没有针对氯吡格雷的DTCA宣传；2001年至2005年，DTCA宣传费用超过3.5亿美元。面向消费者的直接广告宣传并未改变每1000名参保者氯吡格雷配给量的原有趋势（P = 0.10）。然而，在开展DTCA宣传后，单位成本突然且持续增加了0.40美元（95%置信区间，0.31 - 0.49美元；P < 0.001），此后每1000名参保者每季度的药房成本额外增加40.58美元（95%置信区间，22.61 - 58.56美元；P < 0.001）。总体而言，这一变化导致药房总支出额外增加2.07亿美元。
面向消费者的直接广告宣传与氯吡格雷使用量在原有趋势基础上的增加无关。然而，开展DTCA宣传后，由于单位成本随之增加，医疗补助计划的药房支出大幅上升。如果在开展DTCA宣传后药品价格普遍上涨，这将对美国及其他地区的付款方和政策制定者产生重要影响。
