Biomedical Engineering Reference
In-Depth Information
Fig. 22.2
Sales evolution by
class
x 10
7
12
10
8
6
4
2
PPI Class
SSRI Class
Statin Class
0
1996
1998
2000
2002
2004
2006
2008
Years
as they contain many “blockbuster” drugs such as Lipitor, Prilosec, and Prozac. They
also experience a decline in sales during the observation window, thus allowing us to
test life cycle DTCA and DTP effects. The decline should be primarily attributed to
patent expirations associated with agents in these product classes. Specifically, the
SSRI class experienced its first patent expiration in 2001 (Prozac) with more follow-
ing later, in PPIs Prilosec lost its patent in 2002 and introduced an OTC version in
2003, and finally Zocor in Statins lost its patent in 2006.
Promotional variables include DTCA, detailing (DET), and physician journal
advertising (PJA), Internet and promotional meeting and events audits (PMEA), all
in US dollars. Figure
22.2
depicts the sales evolution for the three classes.
Figure
22.3
illustrates the allocation of the budget to the aforementioned promo-
tional activities. Not surprisingly, detailing and DTCA account for more than 85 %
of promotional expenses, both significantly larger than any other alternative.
Figure
22.4
captures the evolution of DTCA and detailing for all three classes.
DTCA exhibits the highest rate of increase in spending, starting at a mean annual
spending of $6.3 million per agent in 1996, and rapidly moving up to $40.2 million
in 2004 where it reaches its peak (Fig.
22.4
). Mean DTCA spending per agent in the
top three drug classes under investigation increased by 560 % in the 8 years follow-
ing the FDA clarification. In addition, Fig.
22.5
suggests that DTCA expenditures
constitute a fairly constant proportion of detailing over time, further suggesting that
DTCA may be anchored to detailing for budgeting purposes. We further examine this
by looking at detailing to DTCA expenditure ratios for each class over time in Fig.
22.6
.
Drugs in PPI and statin classes indeed appear to allocate a fairly constant proportion
of detailing to DTCA but the picture for SSRI is somewhat different, characterized
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