Comparing the costs, risks, and benefits of competing strategies for the primary prevention of venous thromboembolism.

Systematic cost-effectiveness analyses of regimens used for preventing venous thromboembolism (VTE) are becoming increasingly important for several reasons: the aging of the population, with an accompanying increase in admissions for orthopedic procedures or other surgery; expanded indications for thromboprophylaxis in nonsurgical patients; and the introduction of more expensive new agents that may increase safety and efficacy. At the same time, health care systems are under unprecedented pressure to contain the costs of care, particularly medications. Such economic analyses are made more difficult by the paucity of clinical trials comparing treatment regimens to one another rather than to placebo. Several methodological issues must be kept in mind when evaluating cost-effectiveness analyses of VTE prophylaxis. These include the perspective from which the analysis is performed (eg, the health care system as a whole versus a particular payer), limitations of trial data (eg, artificially short time horizons), and definition of outcomes (eg, flawed definition and grouping together of adverse effects or treatment failures). Quantifying costs across nations and health care systems is problematic as well. Another challenge is the extrapolation of efficacy data from highly monitored study patients to routine practice settings. Nevertheless, cost-effectiveness analyses of VTE treatments conducted in orthopedic surgery, trauma, general surgery, and acute medical settings can help define the relationships among expenditures, adverse outcomes, and patient benefit for particular therapeutic strategies in a variety of clinical situations.