Feng, Xiaodong_ Xie, Hong-Guang - Applying pharmacogenomics in therapeutics-CRC Press (2016)

Pharmacoeconomics of Pharmacogenomics
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QALY is equivalent to one year of perfect health. In general, cost- effectiveness
may vary by the strategy or assumptions, 7 and an alternative intervention is considered
cost-effective when the ICE ratio is typically less than USD 50,000 per QALY
gained, a generally accepted cutoff value. 7,9,10,17
Cost-Benefit Analysis
Cost-benefit analysis (CBA) is used to value and measure all costs and all benefits
in economic terms, and to compute a net monetary gain/loss or a cost-benefit ratio.
CBA intends to ignore clinical procedures that may improve the quality or length
of life to be gained, without any direct measurable savings that can be anticipated.
In short, for CBA, the costs are compared with healthcare outcomes in dollar terms
only. Because it is somehow difficult to value the outcomes in dollar terms, CBA
studies are performed less frequently than other types of economic evaluation for
healthcare services, and are also less frequently accepted by healthcare policy
makers. 9,18
Cost-Minimization Analysis
Cost-minimization analysis (CMA), a specific type of economic evaluation, is used
to compare the costs without quantitative comparison to healthcare outcomes, and
then to find the least costly intervention among those shown or assumed to be of
equal benefit. In fact, it is useful only if the healthcare outcomes that need to be
compared are assumed to be the same.
PRACTICE OF PHARMACOECONOGENOMICS
IN CLINICAL SETTINGS
The widespread use of PGx testing in clinical practice is either limited by conflicting
results or indefinite clinical utility, 9,14,15 in particular, for frequently prescribed,
long-term medications. Developing and validating a clinically significant
and practical PGx testing in a cost-effective manner is challenging. For a genetic
variant that occurs in a patient with an unusual drug response (side effects 16,19–21 or
impaired efficacy) or whose functional alteration is known, bringing PGx testing
to the bedside may be cost-effective to some extent. 21 In most (if not all) situations,
patients would benefit more from genotyping of some variant genes throughout
their whole life at a one-time cost, in particular, for those with high-gene penetrance
or those associated with clinical phenotype. The factors that could be used
to predict more cost-effectiveness for PGx-based drug therapies are summarized in
Table 11.1. Obviously, PGx testing cannot provide more additional benefits or ICE
ratio for all drugs, diseases, genes, and patients 7 ; and the ICE ratio of PGx-guided
drug therapy needs to be evaluated on a case-by-case basis. Some well-defined
examples are briefly summarized below to better understand why pharmacoeconogenomics
is more important for some medications, rather than for all medications
in patient care.