State data are a valuable source of information that can enhance decision making for highway safety and injury control activities. These data are usually collected to meet the specific needs of the collection agency: police reported crash data, emergency medical services data, emergency department data, or inpatient data. Each of these data sets alone lacks the comprehensive information required to support highway safety and injury control activities. By linking these data, population-based, computerized statewide data describing the outcome for all crash victims can he generated. This report focuses on how to obtain and prepare state data for linkage. It describes the linkage process but does not include instructions for implementing the linkage software. It provides examples of how to use the linked data analytically. The instructions are presented as a series of steps to be followed sequentially for best results. The 22 steps are grouped into five sections. Section one describes the data, equipment, and personnel resources needed for linkage and the obstacles which may occur. Sections two and three discuss file preparation and selecting the cases for linkage. The actual linkage begins with section four which describes the concepts and phases of the linkage process. Finally, section five describes the output, the validation process, and several applications for the linked data. (A)
Abstract