In this emerging field of study, many different definitions of adverse events are used, and a common terminology has yet to emerge. One of the more difficult problems in discussing patient safety is imprecise taxonomy, since the choice of terms has implications for how the problems related to patient safety are addressed. This imprecision makes comparison of different studies and reporting systems difficult. With few exceptions, existing studies each report data for different populations, and they frequently differ in the way they define, count, and track adverse events. Major variations in nomenclature with no fixed and accepted consensus hamper further research and application.
Adverse event systems have two fundamental components—methods for detecting adverse events and methods for analyzing such events. The remainder of this chapter explores in turn the requirements for each of these components and the implications for data standards. The final section presents a future vision for the use of adverse event systems.
There are many sources of adverse event data. These include the following:
Voluntary and mandatory reporting from internal hospital systems, state and federal systems, and patients themselves and their relatives.
Document review, including patient charts, medical–legal documents, death certificates, coroners’ reports, complaint data, and media reports.
Automated surveillance of patient treatment data, including clinical patient records, hospital discharge summaries, and Medicare claims data that may be a response to a patient injury.
Monitoring of the progress of patients to anticipate conditions that could lead to adverse events or to identify adverse events and implement corrective actions.
Reporting and chart review approaches identify adverse events that have already occurred. The focus is on the analysis of a subset of adverse events to determine root causes and identify improvements in care processes, ultimately improving patient safety.