Converting international cost effectiveness data to UK prices

Sir,

In your editorial you mention that currency conversions make the use
of "foreign" pharmacoeconomic analyses of questionable value. I agree that
currency conversion is a difficult task, particulairly when we have seen
the Euro: US Dollar exchange rate go from 1:$0.80 to 1: 1.08 in less than
two years. However, the problem of external validity or usefulness in
other settings goes far beyond currency conversion issues. Even within the
same country, published analyses tend to be of little value because the
underlying prices or costs of the medications and other resources
themselves tend to vary dramatically between institutions. Drugs that were
prohibitly expensive in one analysis can be dominant (i.e. both more
effective and less expensive) from another institution's perspective.

In the United States, some authors try to get around this problem by
using published "Average Wholesale Prices" ("AWP") supplied by the
manufacturer; however, these are usually a dramatic overstatement of the
amounts actually paid by any real purchaser (including the retail or
consumer perspective).

The remedy to this problem probably lies in authors publishing (or
making available on software) both the description and number of each type
of health care resource used, and the price or cost assigned to it. In
that way, someone in Britain, or Poland, or even in another State in the
USA could substitute either their own unit price or number of resources
they consumed. Rather than stating a given surgery had a cost of $10,000,
if I knew that was comprised of 4 days of stay at a cost of $2,500 per
day, I could open up a computer spreadsheet and rerun the analysis using my
own assumptions, based on the standard of care in my institution or
setting and my cost per unit consumed in that setting.

Unfortunately, such information is often lacking. In unpublished
study of mine, in which 125 studies (1996 - 2001) of cost-effective
devices were described in surgery, only 5 articles actually listed the
unit costs, 2 listed the number of units consumed, and none listed both.
The best information that can typically be found in even a great analysis
is the cost per unit consumed (even that is often concealed for the sake
of preserving "proprietary" information).

Authors and sponsors of pharmacoeconomic research need to realize
that decision-makers require an analysis that is sufficiently transparent;
it can be customized for their own setting, and include access to the
underlying costs and resource consumption. Until then, I will continue to
have doubts as to the extent to which such published material is actually
being used by decision-makers in ANY country.

Lorne Basskin, PharmD