The most recent application of pharmacoeconomic principles and methods has been for justifying the value of various healthcare services, particularly pharmacy services. When a specific service is competing for hospital or MCO resources, pharmacoeconomics can provide the data necessary to show that the service maximizes the resources allocated by healthcare system administrators. Pharmacoeconomics can be useful in determining the value of an existing service, estimating the potential worth of implementing a new service, or capturing the value of a "cognitive" clinical intervention. Practitioners and administrators can then use these data to make more informed resource-allocation decisions.

For example, suppose you want to implement a pharmacy-based therapeutic drug monitoring program. It is hypothesized that this service will improve quality of patient care and save money for the healthcare system. After negotiating with hospital administrators, the funding for this service is approved for a 1-year trial basis, after which you must document and justify the value of this practice. Theoretically, all the relevant costs and benefits of the program should be measured and, if appropriate, converted into dollars using CBA. Potential benefits can include decreased total drug costs and decreased incidence of ADRs. Potential program costs are primarily the salary and benefits for a pharmacist and additional laboratory tests to monitor patients. Data documenting that the benefit of this pharmacy service yields a high return on investment (ROI) should increase the probability of the program continuing to be funded by the healthcare system.

Unfortunately, previous reviews of the literature have revealed a disappointing number of rigorous economic evaluations of clinical pharmacy services published to date.^46–48 However, a review published in 2003 indicates that the quality of published studies finally may be increasing.⁴⁹ Historically, McGhan and colleagues⁴⁶ evaluated 35 potential CBAs or CEAs of pharmacy services published before 1978 and concluded that only five of these studies were legitimate CBAs or CEAs. MacKeigan and Bootman⁴⁷ reviewed 22 CBAs or CEAs published between 1978 and 1987 and concluded that CBAs and CEAs have not been adopted extensively for the evaluation of clinical pharmacy services. In 1996, Schumock and associates⁴⁸ reviewed economic evaluations of pharmacy services published between 1988 and 1995. Of the studies reviewed, only 19 were considered "full" or legitimate economic analyses, and the authors concluded that although the number of articles published has increased over the years, there is still a need for improvement in the quality or rigor of study design. Despite the relatively low number of methodologically sound studies, this review also revealed some results that demonstrate the potential value of clinical pharmacy services. Of the 109 studies evaluated, the various clinical services reviewed in this study yielded an average C:B ratio of 16:1. In 2003, these authors updated their review and included articles published from 1996 to 2000.⁴⁹ After reviewing 59 articles, these authors noted an improvement in the overall quality of the research (more studies included comparison groups and measured both costs and outcomes). Studies were conducted in hospital settings (52%), community pharmacies and clinics (41%), and community/clinic settings (18%). For the studies reporting the statistic, B:C ratios ranged from 1.74:1 to 17.0:1.⁴⁹