Application of the Single Subject Design in Biomedicine

Although there is a long tradition of employing single subject designs in social science research, these designs have only recently been utilized in biomedicine. The single subject design methodology has been overlooked in biomedicine, even though physicians are essentially conducting single subject (N-of-1) trials when conducting patient care (i.e., treating a patient). This research design can be used to study the time course, variability, or effect of an intervention or treatment on a single patient [1]. In a primary care setting, the patient generally exhibits symptoms and the physician follows evidence-based or appropriate steps to treat these symptoms. The physician evaluates the patient’s history, signs, symptoms, medical test results, and examines the patient, and subsequently implements a treatment or intervention if warranted. In order to determine treatment effectiveness, the symptoms are later examined to determine if they are ameliorated or eliminated.