Background: Human factors and ergonomic (HFE) theories and methods have successfully been applied to the work of health care professionals to improve safety, effectiveness, and efficiency of healthcare delivery. HFE approaches have rarely been utilized to explore the performance of patients as active agents engaged in healthcare work. Purpose: The purpose of this study was to describe the nature and prevalence of barriers to medication management performance of older adult heart failure (HF) patients using a patient engaged HFE work system model...