tinuum, there should be identical taxonomies for failure root causes and context variables for both types of events.

The development of near-miss systems works best when the systems are initially established and designed for the benefit of those delivering care, for example, a hospital department. Data from this level can be aggregated for higher-level purposes—reports for hospital-wide systems and domain-specific nationwide systems. However, uses of the data require that the same data standards be applicable across all domains and at all levels of aggregation. Near-miss systems should be an integral part of clinical care and quality management information systems. To foster data reuse across all health care applications, the same data standards should be used for all applications.

In safety management literature, a near miss is defined in various ways. According to one definition, a near miss is an occurrence with potentially important safety-related effects which, in the end, was prevented from developing into actual consequences (Van der Schaaf, 1992). Near misses are also synonymous with “potential adverse events” (Bates et al., 1995b) and “close calls” (Department of Veterans Affairs, 2002). In this report, a near miss is defined as an act of commission or omission that could have harmed the patient but did not cause harm as a result of chance, prevention, or mitigation. In most cases, definitions of a near miss imply a model such as the incident causation model (see Figure 7-1), consisting of the following components or phases (Van der Schaaf, 1992):

  • Initial failures—some instigating failure process (triggered by a human error, a technical or organizational failure, or a combination of the two).

  • Dangerous situation—a state of temporarily increased risk resulting from an initial failure but still without actual consequences.

  • Inadequate defenses—a failure of the official barriers (such as double-check procedures, automatic compensation by standby equipment, or problem-solving teams) built into the system to deal with this risk.

  • Recovery—a second informal set of (mainly human-based) barriers by which a developing risky situation is detected, understood, and corrected in time, thus limiting the sequence of events to a near-miss outcome instead of letting it develop further into an adverse event or worse.

According to the incident causation model, near misses are the immediate precursors to later possible adverse events. Examining near misses provides two types of information relevant for patient safety: (1) that on weak-



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