Background: Primary care physicians' personal knowledge of their established patients has not been investigated systematically, and its role in clinical practice has not been characterized empirically.
Methods: A qualitative study used an iterative, grounded theory method for thematic analysis of transcribed, semistructured long interviews. Subjects were family physicians in stable employment and in continuous clinical practice for at least 2 years at a staff-model health maintenance organization.
Results: Personal knowledge of the patient clearly influenced the use of time in the examination room, the recognition of changes in baseline status, and the ability to verbalize medical information in terms that have unique meaning for particular patients. Personal knowledge fostered a sense of predictability in personal interactions; facilitated the creation of trust; served as an organizing scheme for data collection, recall, and interpretation; counterbalanced impersonal professional principles such as compulsiveness, duty, and responsibility; shaped ability to communicate effectively about issues related to quality of life and functional status; influenced choices of consultants; but also had the potential to interfere with diagnosis or with patient presentation of new information.
Conclusions: Personal knowledge of patients was an important influence on physicians' daily clinical practice in this setting.