Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are now the most common major orthopedic procedures in the world. Outcome research for patients undergoing total joint arthroplasty is now the accepted method of choice for evaluating the results of surgery. This study design incorporates the use of patient-derived data collected from patient self-administered questionnaires that will capture data on the patient's experience of pain, functional disability, and general health status. These questionnaires do not replace traditional measures of clinical endpoints, such as mortality and complication rates, but will be additions to data collection. The patient-derived data allow orthopedic surgeons to assess the impact of total joint arthroplasty on the health status of their patients. The need to collect these data is increasingly necessary with the growing demands on orthopedic surgeons to demonstrate the efficacy of total joint arthroplasty to maintain funding from both public and private funding sources. This article introduces the development of outcome research for patients undergoing total joint arthroplasty.