The investigation of human error

While humans are responsible for all errors, it is often extremely difficult to determine the underlying reason for a problem or complication. Indeed, it is usually a mistake to try to seek out a single cause of a complication in the belief that eliminating that one cause will result in eliminating all future problems of the same kind. Serious, untoward results come from a series of errors: errors of omission and commission and errors of planning and execution. A death in the operating room might easily result from more than one type of error. Errors of commission might be made by someone who carries out a task incorrectly because of a misunderstood instruction. Errors of omission might include the institution's lack of training to ensure that operating-room personnel analyse and improve communications.

The descriptions of errors in this report are a necessary first step in an analysis of how individuals on their own and those responsible for organizations and regulatory agencies can learn from error. While analysis is required, however, it is often hindered by forces that exist within the medical community. These forces seek to minimize the appearance of errors when they occur. This may arise from the fact that the current culture of medicine reinforces the belief that medical personnel must perform without error. All too often, the making of an error in medicine is equated with a moral failing or is regarded as a sign of ignorance or incompetence. To admit to error, or to imply that a colleague's actions were in error, is to raise serious questions about someone's competence, and hence legitimacy and authority within the health-care system. One of the aims of this Report is to contribute to increasing openness about the existence of human error in the medical community.

One of the reasons why the medical system is able to operate as if doctors, nurses and other health-care workers were flawless is the fact that very few errors actually lead to problems or complications for a patient. In a few cases, the potential negative effect of an error does not actually materialize because the error is made in isolation of any other significant factor that might trigger the development of a problem. In most cases, an error such as failure to comply with a standard operating procedure is caught, either by a safeguard that is built into the system, or by medical personnel (by the person making the error or by someone else). In other cases, the effect of an error on the patient's condition is negligible. But this does not happen in all cases-some errors, in combination with other factors, do lead to some patients developing complications, which may range from minor irritation to death.