The Indiana Network for Patient Care (INPC) is a regional computerized patient record system developed by the Regenstrief Institute through a contract with the National Institutes of Health National Library of Medicine (NLM). The purpose of INPC is to improve emergency care through better information. The INPC is being created as a shared database storing emergency room encounter records, hospital abstracts, clinical laboratory data, and other data as available for use by emergency departments (EDs). This database, built on the Regenstrief Medical Record System (RMRS), will encompass 90% of Indianapolis' hospital emergency care, as well as a major share of the laboratory and hospital encounter data of the city. With patients' and health care providers' consent, and under carefully controlled conditions, data from the INPC database is made accessible to health care providers in emergency departments. When a patient presents for care in the emergency department at a participating institution, a printed clinical abstract is generated. The patient's name, medical record number, and chief complaint from check-in are displayed at the top of this printed page along with the patient's most recent results for selected tests. The health care provider also has Intranet access to all of the available data in the INPC through a WWW browser based interface. In addition to time motion studies of providers and user surveys, the value of these resources will be tested in two randomized controlled trials. The effect of these interventions will be evaluated for quality, cost, and access.  The hypothesis is that physicians who have more complete access to a patient's clinical data will make better health care decisions more efficiently.