Human Factors in Perioperative Care: General Principles

What Do We Mean by Human Factors?

There is a significant degree of overlap between HF and other disciplines involved in QI, but the term is often used incorrectly in health care. The World Health Organization (WHO) definition states: “Human factors examines the relationship between human beings and the systems they work in, focusing on improving efficiency, safety, creativity, productivity and job satisfaction.” The overlap with QI disciplines is obvious, the differences perhaps less so. Both QI and HF use a systematic approach to analyzing and rationalizing systems and processes and solving problems. Both advocate close cooperation with frontline staff in devising solutions. HF, however, emphasizes expert professional techniques in systems analysis, whereas QI approaches often rely on frontline workers for both data collection and understanding of the system. The Toyota Production System, for example, used no HF professionals but looked to the frontline worker for both diagnosis and solution of problems. This is potentially risky because frontline staff without systems analysis training may misunderstand complex systems problems, resulting in ineffective initiatives.

Practical Suggestion: If you can afford it, hire an HF specialist to analyze your work process and help you plan your QI approach.

The other obvious distinction between QI and HF is the attention given to humans as sources of both problems and solutions. QI systems create a goal and expect staff to achieve it, with relatively little consideration of their motivation. HF places more importance on studying the humans and their interactions with each other, the system, and the technology they have to deal with. It concerns itself with cognitive, perceptual, and psycho-social issues such as fatigue, hierarchy, and tunnel vision during crisis situations. This provides a richer understanding of the system than standard QI approaches. It is, however, very difficult to compare the effectiveness of HF and QI in improving either quality or safety because of the substantial overlap in their methods and the overriding importance of staff engagement as a success factor for both types of project. Our group conducted a program of safety improvement experiments with surgical operating room (OR) teams, comparing and combining a “Lean” QI approach and a more HF-based systems improvement approach with an approach based purely on teamwork training. We found little difference between the redesign approaches of the two systems, but convincing evidence that the team training acted as an adjuvant to both, whilst having little effect on its own.

The type of team training used in this work, Crew Resource Management (CRM), has been widely advocated in health care and formed the basis for programs such as MedTeams. Its early popularity led many healthcare professionals to associate HF only with this type of team training, focusing on cognitive, perceptual, and communications problems. Although it remains popular, the literature does not present a convincing case for patient benefit. Four systematic reviews have shown a small improvement in outcomes, but this is entirely because of the effect of a single very large Veterans Administration (VA) study, which was biased by an important methodological error. The study compared VA hospitals after training with those that had not yet had it during the roll-out of a system-wide implementation, but the order in which sites received the training was based on “readiness.”

Practical Suggestion: Team training based on HF can enhance engagement with QI programs, so it may be worth considering as an adjunct.

Standard Human Factors Approach to Analysis of Work

HF interventions often begin with ethnographic observation, where the observer tries not to interfere with normal work patterns or team interactions. Photo, video, and documentary evidence may be used, and interviews help build up a picture of how workers see things. The data are used to develop an algorithmic model of the work system, represented by a whole process map plus models of key tasks known as “Cognitive and Hierarchical Task Analyses.” Another HF approach, often used after safety incidents, is to model the influences on work and its outcomes in terms of several dimensions, using a system such as the Systems Engineering Initiative for Patient Safety (SEIPS) model. Key problem areas in a process can be highlighted using Failure Modes and Effects Analysis (FMEA) techniques. FMEA goes through an existing description, such as a hierarchical task analysis, in detail, considering at each step the various ways (modes) in which the step could fail and the likelihood and severity of the effects of such a failure. Multiplying the likelihood by the severity estimate for each step gives a kind of “heat map” of risk within the process ( Table 32.1 is an example).

Table 32.1

A Failure Modes and Effects Analysis (FMEA) Applied to the Accurate Recording and Prescribing of a High-Risk Perioperative Medication (A Parkinson's Disease Medication) ^a

In the currently popular modified version of HF (Safety II, see later), these techniques are replaced by models based largely on qualitative analysis of interviews with frontline staff, such as the Functional Resonance Analysis Method (FRAM). FRAM describes the connections between the “functions” in a process and their nature, classifying these links into six “aspects”: input, output, precondition, resource, control, and time ( Fig. 32.1 ). Safety II is principally concerned with identifying variability in processes and its causes, rather than specifically focusing on risk and error.

Practical Suggestion: FMEA and FRAM provide complementary insights into processes, which can help identify areas for change.

Approach to Improvement

Analysis of the system leads to recommendations for change. The goal in health care, as in other safety critical industries, is to produce highly reliable systems in which harm is minimized, but efficiency, effectiveness, and worker well-being are also desirable objectives, and HF seeks solutions that achieve multiple objectives simultaneously. Some QI systems place great importance on objective measurement as the key driver for improvement, whereas HF tends to regard the impressions and opinions of staff as at least equally important. The core QI methodology of Plan Do Study/Check Act (PDSA/PDCA) cycles is often less formal in HF projects, but the principle of continuous rapid feedback and iteration is retained ( Box 32.1 ). HF specialists also recognize the need for engagement at all levels of the organization for successful change management and, therefore, regularly communicate with senior managers and other important stakeholders.