This document discusses methods for compiling death data from multiple sources at Kaiser Permanente sites. It describes variables like SOURCE and CONFIDENCE used to track the origin and reliability of death record information. Sites obtain data from sources like membership records, hospital discharges, death certificates, and the Social Security Administration. They then develop various processes to select the most reliable data to populate virtual data warehouses. The document recommends standardizing how confidence levels are assigned to improve consistency in evaluating the likelihood of death, accuracy of death dates, and correctness of linked cause of death information.