Derdiarian joined the UCLA School of Nursing faculty in 1974, when cancer-nursing content in curricula was lacking nationwide. In 1976 she obtained a three-year National Institutes of Health grant to implement, as a demonstration project, a graduate curriculum in cancer nursing based on the Johnson Behavioral System Model (JBSM). She then received a second three-year NIH grant to develop and operationally define the JBSM’s theoretical framework in order to measure its efficacy as a research and practice instrument for use in cancer care; this instrument became known as the Derdiarian Behavioral System Model (DBSM). The DBSM instrument was also tested on patients with AIDS and cardiovascular and respiratory diseases. Derdiarian’s other research focused on newly diagnosed cancer patients and their informational needs. Her works were published and replicated in 11 nations. As director of nursing research at the L.A. County-University of Southern California Medical Center, Derdiarian developed and implemented a nursing care quality measurement and improvement program as the basis for a quality improvement information data system that became a national model.