Abstract
Many patients have a primary care physician and an assortment of specialists they might see regularly or even just once. Patients' use of multiple clinicians and clinical organizations increases the need to share health information among providers to reduce the probability of medical errors, improve quality in general, and eliminate unnecessary costs. An obstacle to sharing records is the absence of a common identifier used by all of a patient's providers. This article draws lessons from a demonstration that tested a method to create unique person-specific identification numbers that can increase the probability that patient medical records can be linked.