An instrument for theory and research development using the behavioral systems model for nursing: the cancer patient....

The purpose of the Derdiarian Behavioral System Model (DBSM) instrument was to measure and describe, within the Johnson Behavioral System Model (JBSM) perspective, the perceived behavioral changes of the cancer patient. Based on Johnson's (1968, 1980) premise that illness as a noxious stimulus effects imbalance in the behavioral system of the human being, it was extrapolated that changes that occur in a patient's behavioral patterns would be perceived by the patient. Thus, changes would reflect the description of the imbalance in the patient's behavioral system, which needs to be identified and described in a systematic way. The description of change was envisioned in terms of (1) the perceived existence of change; (2) the direction of change--increase or decrease; (3) the quality of change--positive or negative; (4) the importance of change--its significance; and (5) the physical, psychological, or emotional effect(s) of the illness perceived as causally associated with the change.