James T. Reason

Human error : models and management

The longstanding and widespread tradition of the person approach focuses on the unsafe acts—errors and procedural violations—of people at the sharp end: nurses, physicians, surgeons, anaesthetists, pharmacists, and the like. It views these unsafe acts as arising primarily from aberrant mental processes such as forgetfulness, inattention, poor motivation, carelessness, negligence, and recklessness. Naturally enough, the associated countermeasures are directed mainly at reducing unwanted variability in human behaviour. These methods include poster campaigns that appeal to people’s sense of fear, writing another procedure (or adding to existing ones), disciplinary measures, threat of litigation, retraining, naming, blaming, and shaming. Followers of this approach tend to treat errors as moral issues, assuming that bad things happen to bad people—what psychologists have called the just world hypothesis.

Driving errors, driving violations and accident involvement

A survey of over 1600 drivers is reported, the results of which are consistent with those reported in an earlier study (Reason et al. 1990), which identified a three-fold typology of aberrant driving behaviours. The first type, lapses, are absent-minded behaviours with consequences mainly for the perpetrator, posing no threat to other road users. The second type, errors, are typically misjudgements and failures of observation that may be hazardous to others. The third type, violations, involve deliberate contraventions of safe driving practice. In the present study the survey instrument used, the Driver Behaviour Questionnaire, was also shown to be reliable over time. Each type of behaviour was found to have different demographic correlates. Most importantly, accident liability was predicted by self-reported tendency to commit violations, but not by tendency to make errors or to have lapses. The implications for road safety are discussed.

Beyond the organisational accident: the need for "error wisdom" on the frontline.

Complex, well defended, high technology systems are subject to rare but usually catastrophic organisational accidents in which a variety of contributing factors combine to breach the many barriers and safeguards. To the extent that healthcare institutions share these properties, they too are subject to organisational accidents. A detailed case study of such an accident is described. However, it is important to recognise that health care possesses a number of characteristics that set it apart from other hazardous domains. These include the diversity of activity and equipment, a high degree of uncertainty, the vulnerability of patients, and a one to one or few to one mode of delivery. Those in direct contact with patients, particularly nurses and junior doctors, often have little opportunity to reform the system’s defences. It is argued that some organisational accident sequences could be thwarted at the last minute if those on the frontline had acquired some degree of error wisdom. Some mental skills are outlined that could alert junior doctors and nurses to situations likely to promote damaging errors.

Combating omission errors through task analysis and good reminders

Leaving out necessary task steps is the single most common human error type. Certain task steps possess characteristics that are more likely to provoke omissions than others, and can be identified in advance. The paper reports two studies. The first, involving a simple photocopier, established that failing to remove the last page of the original is the commonest omission. This step possesses four distinct error-provoking features that combine their effects in an additive fashion. The second study examined the degree to which everyday memory aids satisfy five features of a good reminder: conspicuity, contiguity, content, context, and countability. A close correspondence was found between the percentage use of strategies and the degree to which they satisfied these five criteria. A three stage omission management programme was outlined: task analysis (identifying discrete task steps) of some safety critical activity; assessing the omission likelihood of each step; and the choice and application of a suitable reminder. Such a programme is applicable to a variety of healthcare procedures.

Human error: models and management

PERSON APPROACH The long-standing and widespread tradition of the person approach focuses on the unsafe acts—errors and procedural violations—of people on the front line: nurses, physicians, surgeons, anesthetists, pharmacists, and the like. It views these unsafe acts as arising primarily from aberrant mental processes such as forgetfulness, inattention, poor motivation, carelessness, negligence, and recklessness. The associated countermeasures are directed mainly at reducing unwanted variability in human behavior. These methods include poster campaigns that appeal to people’s fear, writing another procedure (or adding to existing ones), disciplinary measures, threat of litigation, retraining, naming, blaming, and shaming. Followers of these approaches tend to treat errors as moral issues, assuming that bad things happen to bad people—what psychologists have called the “just-world hypothesis.”

Behavioural markers of surgical excellence

Abstract This paper applies the concept of behavioural markers of performance, previously used to understand the characteristics of the most successful aviation crews (Connelly, E.P., 1997. A Resource Package for CRM Developers: Behavioural Markers of CRM Skill From Real World Case Studies and Accidents. University of Texas Crew Research Project Technical Report, pp. 97–103; Helmreich, R.L., Merritt, A.C., 1998. Culture at Work in Aviation and Medicine: National, Cultural and Professional Influences. Ashgate Publishers, Aldershot, UK), to a surgical domain. A framework of ‘behavioural markers’ of surgical excellence was developed based on existing research. This framework was used to explain differences in ‘procedural excellence scores’ amongst a group of sixteen UK paediatric cardiac surgeons who had participated in a multi-centre UK study on the influence of human factors on surgical outcomes. Procedural exellence scores were derived from multivariable logistic regression models of the number of major and minor events (i.e. errors) per case, adjusted for known patient risk factors. Two binary outcomes were predicted; death and death and/or near miss. Results showed that those surgeons with the best scores (surgeons 3, 5, 8 and 14) were characterised by more of the behavioural markers than surgeons with lower scores. It is concluded that although behavioural markers have proven a useful method to explain performance differences between surgeons, further research is needed to validate and quantify the markers developed in this study and to test their applicability in other medical domains.

Institutional resilience in healthcare systems

A recent report for the President of the United States described the impact of preventable medical errors as a “national problem of epidemic proportions”.1 Similar concerns have been echoed in the report of an expert group chaired by the Chief Medical Officer.2 In this report it was estimated that 400 people in the UK die or are seriously injured each year in adverse events involving medical devices, and that harm to patients arising from medical errors occurs in around 10% of admissions—or at a rate in excess of 850 000 per year. The cost to the NHS in additional hospital stays alone is estimated at around £2 billion a year. Safety has two faces. The negative face is very obvious and is revealed by adverse events, mishaps, near misses, and so on. This aspect is very easily quantified and so holds great appeal as a safety measure. The other, somewhat hidden, aspect offers a more satisfactory means of assessing safety. This positive face can be defined as the systems intrinsic resistance to its operational hazards. Some organisations will be more robust in coping with the human and technical dangers associated with their daily activities. This will be as true for healthcare institutions as it is for other systems engaged in hazardous activities. In short, some organisations will be in better “safety health” than others. The ideas of resistance and vulnerability can be represented as the extremes of a notional space termed the “safety space” (fig 1). The horizontal axis of the space runs from an extreme of maximum attainable resistance (to operational hazards) on the left to a maximum of survivable vulnerability on the right. A number of hypothetical organisations are located along this resistance vulnerability dimension. The cigar-shaped space shows that most organisations will occupy an approximately …

Types and tokens in road accident causation

Accidents are preceded by long histories containing multitudes of events that constitute promising targets for preventive action. These antecedent events can be classified into at least four groups that occur in this order: failure types; psychological precursors; unsafe acts; and breakdown of defences. It is argued that events directly preceding an accident, such as breakdown of defences and unsafe acts, are only haphazard tokens of the more permanent weaknesses within a system, called failure types. Elimination of a type will therefore have much more impact than the elimination of one or a few tokens. It is also argued that there exist only a limited number of failure types, which are responsible for all accidents. However, in the specific area of road accidents, it is not known which types cause most of the problems. Therefore, their relative importance can only be guessed. We guessed that hardware problems and maintenance are unimportant types; that education and regulations are of moderate importance...

Motion sickness: Some theoretical and practical considerations

This paper reviews some of the more important theoretical and practical considerations relating to the widespread problem of motion sickness. A brief outline is given of the sensory rearrangement theory which seeks to define the essential nature of the nauseogenic stimulus. A wide range of provocative situations is classified as involving either a visual-inertial conflict, or a canal-otolith conflict or both. A number of behavioural measures by which the passenger can minimise the risk of motion sickness are described. Also considered are quantitative studies of vertical oscillatory motion, factors influencing motion sickness susceptibility (sex, age, exposure-history, receptivity and adpatability and personality characteristics), and the paper concludes with recommendations regarding the most effective use of anti-motion sickness drugs.

Human factors research in cardiac surgery: opportunities and pitfalls

PROFESSIONAL, public and political pressure, the medical field is becoming increasingly aware of the need to understand the role played by human error in adverse events (i.e. near misses, critical incidents and deaths). In a recent edition of the British Medical Journal, the need to collect data on adverse events using a systems approach was discussed. Similarly, the Department of Health report entitled An organisation with a memory has emphasized the importance of developing a learning culture where clinicians can report errors and incidents without fear of being reprimanded.