The growing emphasis on cost-effectiveness in the United States health care industry has highlighted the need for comprehensive outcomes research in a variety of medical specialties. Currently, there is a relative paucity of reliable data characterizing the long-term results of many medical and surgical treatments. This shortage of outcomes research is particularly acute within plastic surgery where the benefits of treatment are often intangible and notoriously difficult to measure. In evaluating the effectiveness of medical treatment, conventional clinical research has focused primarily on morbidity and mortality as the outcomes of interest. In contrast, current outcome studies assess the results of interventions from the patient's perspective, measuring the impact of medical care on physical functioning, well-being, and quality of life. The resulting data can assist consumers, providers, and payers in making more appropriate health care decisions. As the outcomes movement has matured, it has evolved into two major areas of study: effectiveness research that evaluates the relationships between specific medical interventions and outcomes of care, and quality assessment that seeks to provide the best outcomes at the most reasonable costs. This review details the origins and trends of current outcomes research, examining the implications of this movement for plastic surgery. The growing impact of outcomes data on treatment guideline formulation in both the public and private sectors is also described. Finally, a brief review of outcomes study design, including definition of variables and selection of instruments, is presented.Wilkins EG, Lowery JC, Smith Jr DJ. Outcomes research: a primer for plastic surgeons.