This paper provides an overview of the key elements of cost effectiveness analysis (CEA). CEA is a method for evaluating the relative costs and benefits of treatments and procedures. Typically, CEA compares a proposed intervention with (at least) one alternative intervention, yielding an incremental cost effectiveness ratio. This ratio reflects both the longevity and health status of the differing interventions and permits the researcher to more completely compare and evaluate the "payoff" of the interventions. This paper discusses different perspectives CEA studies might adopt, and reviews the major methods for measuring both outcomes and costs.