Pharmacoeconomics of antimicrobial prophylaxis.

Pharmacoeconomic analysis of the prevention of infection is based on quantification of the benefits which result from prevention, rather than simple counting of the number of cases prevented. In general, benefits are best quantified as continuous variables which measure severity as well as occurrence, for example, cost of antibiotics prescribed is a useful continuous measure of severity to add to a discontinuous measure, such as number of patients who received antibiotics. Considerable progress has been made in the USA with the application of decision analysis to clarify the options available for dealing with a problem, the probability of good and bad outcomes for each choice and the utility which is associated with each outcome. These techniques deserve wide application. Much existing practice is based on limited, poor quality information about the occurrence and severity of infection. This situation can only be improved by wider application of standardized methods for definition of occurrence of infection and of underlying risk of infection.