Human Factors


  • Human failures rather than technical failures are the greatest threat to complex and potentially hazardous systems such as  healthcare systems.
  • In aviation, over 70% of adverse events are due to human factors – data suggests a similar rate in healthcare
  • Managing the human risks will never be 100% effective. Human fallibility can be moderated, but it cannot be eliminated.


Different types of error:

  • have different underlying mechanisms
  • occur in different parts of the organization
  • require different methods of risk management

Error types

  • Execution failures (actions deviate from the intention)
    — Slips (attention failures), lapses (memory failures), trips, and fumbles
  • Planning or problem solving failures (things go to plan, but the plan is wrong)
    — mistakes


  • Rule-based mistakes
    — misapplication of a good rule
    — application of a bad rule
    — non-application of a good rule
  • Knowledge-based mistakes
    — a novel problem where the solution has to be worked out
    — slow resource-intensive reasoning based on an incomplete or inaccurate ‘mental model’ that is subject to cognitive biases


  • Violations are deviations from safe operating practices, procedures, standards, or rules.
  • may be deliberate or unintentional
  • deliberate violations are distinct from errors as they involve motivational problems, not problems with information handling
  • violations involve social context, errors do not
  • motivational and organizational remedies are needed rather than improved information quality and delivery

3 main groups

  • routine violations (cutting corners whenever possible)
  • optimizing violations (actions taken for personal rather than task-orientated reasons)
  • necessary or situational violations (needed to get the task done because the rules or procedures are seen as inappropriate to the task)


Two types

  • active
  • latent

Active failures

  • unsafe acts (errors or violations) committed by those in direct contact with the patient (at “the sharp end”)
  • almost immediate effect

Latent failures

  • Latent failures arise in organizational and managerial spheres
  • adverse effects may take a long time to become evident
  • become evident when combined with a local triggering event
From Reason, 1995


Retro-fixes to prevent events, sanctions, retraining and other ‘anti-personnel’ countermeasures are ineffective

  • those at the sharp end are the inheritors of the accident sequence, they do not choose to error and are not necessarily especially prone to error – if the individual cannot control it, neither can the organisation
  • psychological factors are the last links in the chain and the least manageable
  • accidents are rarely due to single unsafe acts, as long as the alternate errors remain the potential for other acts to lead to adverse events remains
  • these countermeasures create a false sense of security
  • increased automation does not prevent human factors from leading to adverse events, just changes their nature (as systems are made more opaque, errors often become less likely, but  with greater potential for mistakes)


Effective risk managements aims to improve human performance at all levels of the system, rather than to minimise particular errors and mistakes.

  • Effective risk management depends critically on a confidential and preferable anonymous incident monitoring system that records the individual, task, situational, and organisational factors associated with incidents and near misses.
  • Effective risk management means the simultaneous and targeted deployment of limited remedial resources at different levels of the system: the individual or team, the task, the situation, and the organisation as a whole.
  • Automation and increasing advanced equipment do not cure human factors problems, they merely relocate them. In contrast, training people to work effectively in teams costs little, but has achieved significant enhancements of human performance in aviation.
  • People do not act in isolation. Their behaviour is shaped by circumstances. The same is true for errors and violations. The likelihood of an unsafe act being committed is heavily influenced by the nature of the task and by the local workplace conditions. These, in turn, are the product of “upstream” organizational factors. Great gains in safety can ve achieved through relatively small modifications of equipment and workplaces.

Effective risk management addresses:

  • team factors
  • task factors
  • situational factors
  • organizational factors


Important team factors that reduce error identified from aviation disasters applied to medical teams:

  • establishment of team concept and environment for open communications
  • briefings are thorough and address team coordination and planning for all important contingencies
  • all relevant participants are included as part of the team
  • group climate is appropriate to the operational situation (social interaction must not interfere with necessary tasks)
  • team members ask questions regarding team actions
  • team members speak up and persist until there is appropriate resolution
  • team leader coordinates team activities, establishes proper balance between authority and team participation, and is decisvie when required
  • workload and task distribution is clearly communicated and acknowledged by team members and appropriate time is allocated to tasks
  • secondary tasks are appropriately prioritized so that sufficient resources are allocated to complete primary tasks
  • team prepares of expected contingencies
  • when conflicts arise team remains focused on the problem at hand
  • team members listen actively to opinions and ideas and admit when they are wrong


  • identify and modify tasks and task elements that are prone to failure
  • efficient incident monitoring


7 broad categories of error producing conditions:

  • high workload
  • inadequate knowledge, ability or experience
  • poor interface design
  • inadequate supervision or instruction
  • stressful environment
  • mental state (fatigue, boredom, etc)
  • change

7 broad categories of violation producing conditions:

  • lack of safety culture
  • lack of concern
  • poor morale
  • norms condoning violation
  • “can do” attitudes
  • apparently meaningless or ambiguous rules


  • accident and incident reporting procedures should record events that occur at all levels, and ideally be confidential and anonymous
  • continuous sampling of measures of quality are also important determinants of patient safety, however the parameters to assess may be arbitrary
  • simultaneous and targeted deployment of limited remedial resources at different levels of the system

References and Links

  • Understanding adverse events: human factors. Qual Health Care. 1995 Jun;4(2):80-9. PMC1055294.

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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