Pharmacoeconomics evaluates the costs and benefits of drug therapies and health programs. It uses economic evaluation methods like cost-effectiveness analysis, cost-utility analysis, and cost-benefit analysis to compare treatment alternatives. These methods measure costs in monetary terms and outcomes in natural units or quality-adjusted life years. The results are used to inform healthcare funding and policy decisions by identifying the most efficient use of resources to maximize health benefits. However, pharmacoeconomic evaluations have limitations as they require subjective valuations and assumptions which can introduce bias.