Introduction and Objectives: Health economic analyses are used routinely to evaluate a number of types of health care interventions and are required for all new pharmaceuticals by many national and regional health authorities. These analyses assess the implications of projected outcomes and costs of a new drug treatment, and are often used as a tool to guide decisions about pharmaceutical development and consumption. As an illustrative example, an overview of the components and construction of an economic model are presented here using the costs and outcomes associated with fesoterodine (FESO), a new antimuscarinic that has been shown to be safe, tolerable, and effective for the management of overactive bladder (OAB) in adults.
Methods: Economic evaluations comparatively assess the costs in terms of resources consumed and consequences of the drug (e.g., FESO therapy). The type of analysis illustrated is a cost utility analysis (CUA), which focuses particular attention on the costs and incremental health improvement attributable to fesoterodine. The costs of treatment are measured in monetary units and include medical costs purchased by the health care system, including physician visits, diagnostic and laboratory tests, hospitalizations, and so forth. Other costs consist of the patient’s out-of-pocket expenses for goods and services outside of the medical sector, such as incontinence pads. Unpurchased resources consumed by patients with OAB include lost productivity while at work or lost time from work owing to the condition. Health improvement due to FESO is measured by quality-adjusted life years (QALYs, pronounced “qualies”). The QALY is a measure of health outcome, which assigns to each period of time a weight, ranging from 0 (death) to 1 (perfect health) corresponding to the quality of life during that period. The need for incorporating QALYs, rather than life years or expectancy, is due to the observation that many medical interventions, such as those for OAB, are not associated with premature death but with changes in morbidity and quality of life. Finally, the central outcome in a CUA is the cost-utility ratio, or the difference in the costs of the 2 alternatives divided by the difference in QALYs. This ratio is essentially the cost of an additional QALY when using 1 intervention compared with an alternative.
Results: ACUA was created examining the costs and benefits of FESO demonstrated in a 12-week, randomized, double-blind, placebo- and active-controlled clinical trial. Comparators were FESO 4 mg/d, FESO 8 mg/d, extended-release tolterodine 4 mg/d (TOL), and solifenacin (SOL). SOL was not included in the clinical trial; therefore, efficacy data were obtained from the published literature. Medical costs of OAB (antimuscarinic drugs, physician visits, laboratory tests, and OAB-related comorbidities), patient out-of-pocket costs (incontinence pads), and productivity costs (lost productivity at work and lost time from work) were all considered. Health-related quality-of-life data were collected during the trial via the King’s Health Questionnaire (KHQ). Using a published algorithm, responses to the KHQ were transformed into QALYs. The timeframe of the analysis was extended from the 12-week trial period to 52 weeks, and the total expected costs and the expected QALYs for each intervention were used in 2-way comparisons. The QALYs gained were 0.0111, 0.0115, 0.0124, and 0.0143 for TOL, SOL, FESO 4mg, and FESO 8mg, respectively. The overall costs were $2 102.19, $2 183.54, $2 212.78, and $2 313.51 for FESO 8mg, SOL, FESO 4mg, and TOL, respectively.
Conclusions: Economic analyses are used by decision makers in conjunction with clinical and other information to decide which drug therapy provides the best economic value. The results of our economic analysis suggest that FESO may result in fewer overall costs and greater QALYs gained than treatment with TOL or SOL for the management of patients with OAB and incontinence.
KEYWORDS: Fesoterodine, cost-effectiveness, cost utility, economic model, OAB, incontinence