RELATIONAL DATA TABLES

Eight relational data tables were created based on information from the EMRs, claims data, and discharge abstract data (Table 1). The patient profile file included information about the patients and the medical institutions where they received care. The admission file contained admission and discharge dates, whereas the drug file included information on prescribed drugs. When available, drug file also includes information about bring-in drugs (i.e., drugs that patients bring). The laboratory testing file includes information about all types of specimen tests (e.g., blood, urine) although physiological function tests (e.g., electroencephalogram, electrocardiogram) and imaging tests (e.g., computerized tomography, magnetic resonance imaging) are not recorded in current stage. There are two files for diagnosis information: one was derived from EMRs and the other from claims data. The procedure file contained all medical practices under a uniform national fee schedule. The discharge abstract file included information about diagnosis, surgery, and clinical conditions (e.g., activity of daily living and coma at admission) in some acute care hospitals (i.e., “DPC” hospitals). All tables contained a unique patient identifier and, therefore, they could be linked together.

DPC, Diagnosis Procedure Combination; EMRs, electronic medical records; ICD, International Classification of Diseases.