Hindsight bias

The psychological phenomenon called hindsight bias plays such an important role in attribution of causes to accidents that it is worth spending time on it. The report on the Clapham Junction railway accident in Britain concluded  

There is almost no human action or decision that cannot be made to look flawed and less sensible in the misleading hght of hindsight. It is essential that the critic should keep himself constantly aware of that fact. [82, pg. 147] 

After an accident, it is easy to see where people went wrong, what they should have done or not done, to judge people for missing a piece of information that turned out to be critical, and to see exactly the kind of harm that they should have foreseen or prevented [51]. Before the event, such insight is difficult and, perhaps, impossible. 

The attribution of operator error as the cause of accidents is discussed more thoroughly in Safeware (chapter 5). 

Avoiding hindsight bias requires changing our emphasis in analyzing the role of humans in accidents from what they did wrong to why it made sense for them to act the way they did. 

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Christensen-Szalanski J.J.J., Willham C.F., 1991. The hindsight bias A metaanalysis, Organizational behavior and human decision processes 48, pp. 147-168. 

There is evidence that the hindsight bias can be moderated by familiarity with both the task and the type of outcome information provided (Christensen-Szalanski and Willham 1991). 

Christensen-Szalanski, J. J., and WiUham, C. F. (1991), The Hindsight Bias A Meta-Analysis, Organizational Behavior and Human Decision Processes, Vol. 48, pp. 147-168. 

One goal of CAST is to get away from assigning blame and instead to shift the focus to why the accident occurred and how to prevent similar losses in the future. To accomplish this goal, it is necessary to minimize hindsight bias and instead to determine why people behaved the way they did, given the information they had at the time. 

Stopping after identifying inadequate control actions by the lower levels of the safety control structure is common in accident investigation. The result is that the cause is attributed to operator error, which does not provide enough information to prevent accidents in the future. It also does not overcome the problems of hindsight bias. In hindsight, it is always possible to see that a different behavior would have been safer. But the information necessary to identify that safer behavior is usually only available after the fact. To improve safety, we need to understand the reasons people acted the way they did. Then we can determine if and how to change conditions so that better decisions can be made in the future. 

One of the most common mistakes in accident analyses is the use of hindsight bias. Words such as could have or should have in accident reports are judgments that are almost always the result of such bias [50]. It is not the role of the accident analyst to render judgment in terms of what people did or did not do (although that needs to be recorded) but to understand why they acted the way they did. 

Although hindsight bias is usually applied to the operators in an accident report, because most accident reports focus on the operators, it theoretically could be applied to people at any level of the organization The plant manager should have known. .. ... 

The biggest problem with hindsight bias in accident reports is not that it is unfair (which it usually is), but that an opportunity to learn from the accident and prevent future occurrences is lost. It is always possible to identify a better decision in retrospect—or there would not have been a loss or near miss—but it may have been difficult or impossible to identify that the decision was flawed at the time it had to be made. To improve safety and to reduce errors, we need to understand why... 

The accident report concluded, The available evidence should have been sufficient to give the control room operator a clear indication that [the tank] was indeed filling and required immediate attention. This statement is a classic example of hindsight bias—note the use of the words should have. .. The report does not... 

To overcome hindsight bias, it is useful to examine exactly what evidence the operators had at time of each decision in the sequence of events. One way to do this is to draw the operator s process model and the values of each of the relevant variables in it. In this case, both operators thought the control valve was closed—the control room operator had closed it and the control panel indicated that it was closed, the flow meter showed no flow, and the outside operator had visually checked and there was no flow. The situation is complicated by the occurrence of other alarms that the operators had to attend to at the same time. 

Hindsight bias and focusing only on the operator s role in accidents prevents us from fuUy learning from accidents and making significant progress in improving safety. 

Hindsight bias is mentioned several times in the table. What is hindsight bias The term derives from the psychological literature and in particular from... 

Record review/chart review Uses readily available data Commonly used Judgements about adverse events not reliable Medical records are incomplete Hindsight bias... 

Hindsight bias has another facet, perhaps better termed outcome bias, which is particularly relevant in healthcare. When an outcome is bad, those looking back are much more likely to be critical of care that has been given and more likely to detect errors. For instance, Caplan, Posner and Cheney (1991) asked two groups of physicians to review sets of notes. The sets of notes were identical... 

Case analysis/Root Can suggest contributory Hindsight bias... 

Hindsight bias and memory failure Extreme over-confidence Vulnerable to environmental influences Lack of control over thought and action Flexibility and adaptability Experience and wisdom Anticipation of hazards Recovery from error... 

Hindsight bias Overestimating probability of a diagnosis when the correct diagnosis is already known... 

One of the key challenges in this review is hindsight bias and other form of bias. Hindsight is based on... 

The issue of hindsight bias was not explicitly discussed or evaluated in the reports. In one case a prior survey of safety culture before the accident indicated a focus on safety, while the accident report indicated poor focus on safety, ref Antonsen (2009). The hindsight bias could be useful to reflect on in the accident reports, to uncover underlying factors or root causes that may have been missed or misrepresented. 

The study of patient safety is the study of complexity. The study of complexity invites us to understand key concepts that can be applied to patient safety. Basic concepts from the fleld of patient safety are sharp and blunt end active and latent failure the Swiss Cheese Model of Accident Causation slips, lapses, and mistakes and hindsight bias and the fundamental attribution error. Key concepts from organizational analysis, such as normalization of deviance, diffusion of responsibility, tightly coupled work processes, and sensemaking, introduce practical lessons from high-reliability organizations. Application of specific lessons to health care are explored in Chapter Five. 

As a participant in his hospital s patient safety initiative, pediatric emergency physician Tom Hellmich attended several educational sessions where he learned about basic concepts in safety, such as hindsight bias and the Swiss Cheese Model. The lessons proved useful during a particularly busy week at work. In one day, two children, one in the hospital s emergency department and the other in an inpatient unit, suffered a cardiac arrest, requiring a code to be called. 

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