ship in ecological studies of suicide, the further understanding of the association between firearms and suicide will be particularly dependent on the availability of direct information about gun ownership. Potentially valuable state-level information could be made available through the regular inclusion of gun ownership questions in the Behavioral Risk Factor Surveillance System, and a better understanding of the possible linkage between household gun ownership and adolescent risk-taking might come from the regular inclusion of household gun ownership questions, in addition to the existing adolescent gun use questions, in the Youth Risk Behavior Surveillance System.
At the moment, the U.S. vital statistics system is the only source of nationally representative information about lethal self-injuries. This system sets important limitations on present knowledge. The proposed National Violent Death Reporting System, now being piloted in six states with funding from the Centers for Disease Control and Prevention, could provide more information about demographic background, intent, circumstances, precipitants, method of injury, and source of the firearm (in the case of gun suicides) than is presently available. In this regard, it may be a much more significant improvement for the study of suicide than for the study of homicide, for which similar national data systems are already available.
But there are potential problems that should be considered in the planning of such a system, which might affect the overall usefulness of the final result (see Chapter 2 for further details). Data systems that collect information about a series of cases (such as the recording of injuries or deaths) cannot be used without an appropriate comparison group to make valid inferences about the association between exposures and outcomes. Will the data be collected in a way that would permit such comparisons? This might be accomplished by using the injury surveillance system in the way that cancer registries are now used, as a source of cases for case-control or record-linkage studies of the risk factors for the designated outcome. Will the data system collect sufficiently complete and reliable information about relevant exposures? It would be helpful to develop the NVDRS system with several specific research questions in mind, to ensure that the system will actually be usable, and will actually be used.
The committee recommends further individual-level studies of the link between firearms and both lethal and nonlethal suicidal behavior. It would be useful to have an ongoing, longitudinal study that determines both predictors of gun ownership and other known risk factors for suicidal thoughts, nonlethal suicidal behaviors, and completed suicide. Added detail about method choice and correlates of gun ownership would help to clarify