INTRODUCTION:

Unsafe healthcare is a major source of morbidity and mortality throughout the world. Estimates show that in developed countries as many as one in 10 patients is harmed while receiving hospital care. Of every hundred 100 hospitalized patients at any given time, 7 in developed and 10 in developing countries will acquire health care-associated infections.¹ Hundreds of millions of patients are affected by patient safety issues worldwide each year. Adverse events or medical errors are generally not caused by a single mistake or error. Increasingly complex health care, involvement of multiple disciplines and varied sources of information in patient care all can be attributed to the increasing likelihood and impact of medical errors and health care associated adverse events.²

In addition, in developing countries health professionals are expected to carry out their job and deal with complicated situations with very limited resources. Often doctors and nurses have not received adequate training, are not adequately supervised, do not have protocols to follow or the means to record patients' information, and in some cases do not even have running water with which to wash their hands.

There is always the likelihood of errors occurring in health care due to the human factor. However, often it is factors external to people, such as the environment in which they work, which lead to errors. Although preventive barriers or safety mechanisms exist in health care organizations, patients are still harmed as these barriers are not perfect and contain weaknesses that may be bypassed if the right conditions exist. Hence the investigation and analysis of adverse events must focus on identifying these conditions and the weaknesses in safety barriers. Unfortunately the historical approach to error investigation has focused solely on the people involved and this fails to correct the weaknesses within the system which allow errors to occur.

Conceptual models of health care associated errors and their prevention:

Several models and conceptual framework have been developed in understanding the context in which errors or adverse events happen in health care system and thus designing methods for prevention of errors and maintain a patient safety culture. James Reason and others have argued that errors cannot be understood in isolation, but only in relation to the context in which people are working. In considering how people contribute to accidents therefore we have to distinguish between active failures and latent errors. The active failures are errors and are committed by people working in the sharp end of the system who are actually operating it or working with a patient. These are actions and behaviors that are directly involved in an accident like action slips or lapses. Mistakes like that might happen because of lack of medication knowledge, selecting the wrong medication for the patient, violations or work- arounds like not checking patient identification before medication administration. Latent error is a human error which is likely to be made due to systems or routines that are formed in such a way that humans are disposed to making these errors. Latent conditions are the ‘inevitable resident pathogens within the system that arise from decisions made by managers, engineers, designers and others. However, other factors further back in the causal chain can also play a part in the genesis of an accident. The latent conditions often termed as a foundations for accidents in the sense that they create the conditions in which errors and failures can occur.

The dynamic safety model of Cook and Rasmussen describe how errors and incidents happen when healthcare systems operate at almost maximum capacity. Under such circumstances operations become to migrate towards the marginal boundary of safety, therefore putting the system at greater risk for accidents. This migration is influenced by management pressure towards efficiency and the gradient towards least effort, which result from the need to operate at maximum capacity. Because this addresses the dynamic aspects of safety, this model is particularly suited to understand current conditions in modern healthcare delivery and the way these conditions may lead to accidents.³

World Health Organization (WHO) has put forward human factors principles to understand relationships between humans-humans, humans-medical equipment, and humans-environment. They devised a classification which transforms patient safety information collected from disparate systems into a common format to facilitate aggregation, analysis and learning across disciplines, borders, and time. This work had culminated in a conceptual framework consisting of ten high level classes; incident type, patient outcomes, patient characteristics, incident characteristics, contributing factors/hazards, organizational outcomes, detection, mitigating factors, ameliorating actions, and actions taken to reduce risk. This concepts represent the start of an on-going process of progressively improving a common international understanding of terms and concepts relevant to patient safety. Multiple factors, which affect ‘brain processes and responds’ and influence ‘personal performance’ negatively, need to be prevented and mitigated for intended safety outcomes ⁴

Accident causation model by Reason is a constructive way of identifying the underlying causes of adverse events. It prompts the researcher to identify specific causes of an adverse event rather than blaming the people involved. It promotes an examination of the organizational or system factors which contributed to the event including failure of safety barriers. He proposes that within complex systems such as hospitals, multiple barriers or layers exist to prevent accidents or errors. In health care these layers may include hospital policies, protocols or clinical guidelines. He has distinguished two simple ways or contexts in which failure occurs. These failures may be labelled as either an error or a violation; the plan is adequate but the associated actions do not proceed as intended, or the actions go as intended but the original plan was flawed. ⁵

Vincent and Colleagues have proposed an organizational accident model based on the research by Reason. According to this model, accidents or adverse events happen as a consequence of latent failures (i.e. management decision, organizational processes) that create conditions of work (i.e. workload, supervision, communication, equipment, knowledge/skill), which in turn produce active failures. Barriers or defenses may prevent the active failures to turn into adverse events. This model defines 7 categories of system factors that can influence clinical practice and may result in patient safety problems; (1) institutional context, (2) organizational and management factors, (3) work environment, (4) team factors, (5) individual (staff) factors, (6) task factors, and (7) patient characteristics.⁶

Wagenaar et al in their model suggested that accidents are the end result of long chains of events that start with decisions at the managerial level. Accidents are built into an organization’s infrastructure rather than being deliberately caused. Management decisions such as reducing the number of maintenance staff; general failure types such as inadequate time to complete a task; psychological precursors such as a wrong habit which worked well in the past; unsafe acts such as touching a loose electrical wire; and missing defenses such as no triggering of an alarm if a drug cupboard is forcibly opened are proposed as the attributing factors for errors happen in healthcare.⁷

Karsh et al have proposed a model of patient safety that defines various characteristics that influences the performance of the healthcare professional who delivers care. The performance of the healthcare professional can categorized into (1) physical performance (e.g., carrying, injecting, charting), (2) cognitive performance (e.g., perceiving, communicating, analyzing, awareness) and (3) social/behavioral performance (e.g., motivation, decision-making). Performance can be influenced by various characteristics of the work system, including characteristics of the worker and his/her patients and their organization, as well as the external environment. ⁸

Human Factor engineering:

Human factors engineering is the discipline that uses methods and concepts to understand and build systems that are more efficient, comfortable, and safe.⁹ It will also help the personnel involved in patient safety to analyze events and develop workable and effective counter measures. Human factors engineering process focuses on user needs, user characteristics, and end user testing of the human–machine interface while utilizing aspects of several biomedical disciplines, including anthropometrics, biomechanics, sensation and perception, anatomy and physiology, and cognitive psychology which covers models and theories of human performance, memory, and attention. In addition, design or process is repeatedly refined throughout based on feedback from the user to ensure that the system being designed meets its intended purpose and operates in its intended manner. This is because safety practices that have designed to work in one context may not work in another one. Also to be effective patient safety has to be addressed from a systems perspective examining the situation and putting in place mechanisms to minimize the risks, while addressing all the possible latent causes that lead to poor outcomes. Hence a comfortable and effective patient safety culture requires a multi-faceted systemic approach.

Human factors:

Human Factors, often referred to as ergonomics, is a sub domain of human factors engineering. Though it has been practicing in many safety critical industries, only recently it has received attention from healthcare industry. Catchpole et al define human factors as enhancing clinical performance through an understanding of the effects of teamwork, tasks, equipment, workspace, culture, and organization on human behavior and abilities, and application of that knowledge in clinical settings.¹⁰ Another definition by the Health and Safety Executive (UK industrial safety regulator) is ‘human factors refer to environmental, organizational and job factors, and human and individual characteristics which influence behavior at work in a way which can affect health and safety.¹¹ The word ergonomics means the use of theories, principles and methods to design and redesign system and system elements to fit to human and to improve human performance and system performance. Thus human factors and ergonomics examines the relationship between human beings and the systems with which they interact by focusing on improving efficiency, creativity, productivity and job satisfaction with the goal of minimizing errors. It is about understanding human limitations and designing the workplace and the equipment we use to allow for variability in humans and human performance. Thus a simple way to view human factors is to think about three aspects: the job, the individual, and the organization and how they impact on people’s health and safety-related behavior.’

Domains of human factors or ergonomics:

According to international ergonomics association there are three major domains

· Physical ergonomics:

Concerned with physical activity and focuses primarily on the physical characteristics of the person. This domain is particularly applicable and relevant in areas like intensive care units and emergency departments. Eg

o Minimizing the time required for perception, decision or manipulation

o Reducing or mitigating the need for excessive physical exertion

o Optimizing opportunities for physical movement

· Cognitive ergonomics:

Concerned with mental or cognitive characteristics of the person

o Ensuring consistency of interface design

o Matching between technology and the user's mental model

o Minimizing cognitive load

o Allowing for error detection and recovery

o Providing feedback to users

· Organizational ergonomics:

Concerned with socio-technical systems or psychosocial characteristics of the person like job stress, burnout of healthcare ,organizational structure, leaning culture, work schedule, and organizational; design.

o Providing opportunities to workers to learn and develop new skills

o Allowing worker control over work system

o Supporting worker access to social support

o Involving users in system design.¹²

Principles of human factor or ergonomics:

Failure to apply human factors principles is a key aspect of most adverse events in health care. Many principles and approaches have been adopted to improve and optimize patient safety in health organizations.

· Simplifying process will help to clarify the meaning and ensure that an item’s purpose is easily understood by the user. If a process is too difficult people may not do it or else they will find their own easy ways of doing the same things. When designing processes and systems, organizations should make it easy to do the right thing and hard to do the wrong thing.

· One of the best ways to reduce errors related to performance is to standardize and thus helps to eliminate variation and confusion and thus promote predictability and consistency. A well-designed standardized process will reduce complexity and variation.

· In addition to simplification and standardization, it is also important to add redundancies into complex processes.

· The human brain can reliably hold only between five and seven pieces of information at a time. Well, it is no different in health care. When engaging in a complex process it is helpful to use a checklist to make the process complete, so as to avoid reliance on memory.

· Working as a team and communicating effectively can mitigate the factors that contribute to errors. When working as a team, each member has a better understanding of the other members’ competence and reliability. When factors such as fatigue and distractions begin to interfere with an individual’s performance, they become more evident to the team, and the team will act as a unit to mitigate the impact.

· Automation using technology provides many advantages when used to mitigate the effects of factors contributing to error. We can use technology as a reminder system, a reliable way to ensure that a task is completed as designed, a screen for errors, and so forth.

· Take advantage of habits and patterns. Habits are those actions we perform in consistent circumstances and are triggered by our surroundings. A pattern is a recognizable regularity in events. In health care, it can also be important to design processes around the habits and patterns of the patient and the staff. For example, to ensure that patients bring their medication lists to each office visit or when admitted to a hospital, a number of organizations examined habits and patterns of patients.¹³

Levels of human factors or ergonomics:

Hendrick and Kleiner have defined a number of ‘levels’ of human factors or ergonomics:

· Human-machine interface technology or hardware ergonomics: Concerned with the design of technologies, work layouts, and facilities. It draws primarily on knowledge, concepts, and methods of physical and cognitive ergonomics.eg; controls in telemetry monitoring unit, display of an anesthesia machine and workspaces.

· Human-environment interface technology or environmental ergonomics: Concerned with environmental issues like noise, temperature, airflow, and vibration.

· Human-software interface technology or cognitive ergonomics: It varies with the increasing number and diversity of devices, equipment, and technologies designed and implemented in healthcare like usability, usefulness, workload, and error recovery.

· Human-job interface technology or work design ergonomics: Concerned with the way the work is designed and organized.eg; work schedule, task allocation, and work content.

· Human-organization interface technology or macro ergonomics: Eg; team work, organizational culture and learning, work system, socio technical system, and high reliability organizations.¹⁴

Actionable recommendations for the design and implementation of human factors or ergonomics:

From an organizational human factors viewpoint, work systems should be designed so that tasks are reasonably demanding physically and cognitively. Workers should have opportunities to learn adaptive levels of control over their work system and access to social and instrumental support (eg, support from coworkers in case of emergency) within the work environment.

· Consider human characteristics including body size, strength, and mental capability.

· Consideration should be given to all foreseeable operating conditions including upsets and emergencies.

· Consideration should be given to the interface between the end user and the system.

· Make sure the equipment / system provided is easy, efficient, and safe to use by staff and where intended by the public.

· Ensure required systems training, procedures, and documentation at the right time and to a consistently high standard

· Classify and design process into normal, abnormal, degraded, and emergency operating conditions.

· Have a process to log, track down, and close out identified issues.

· The system should not place undue demands on error-free and/or rapid human actions in response to emergency situations

· Operators should be able to perform their tasks in a sustained manner without excessive workload, exceptional time pressure, significantly reduced levels of alertness or the need to use novel actions or procedure

· Any equipment (hardware and/or software) provided for operators should support their needs and be tolerant of human error. It should be designed to avoid any loss of confidence in or frustration with the equipment by users

· Equipment should be designed to minimize the need for trained operators to have frequent recourse to user instructions or to other forms of help or written procedures

· Human factors effort should be proportionate to the size of the project, novelty of technology, and the consequences of human failures

· Assurance and testing, such as a statement of the necessary risk controls including personnel characteristics, staffing numbers, required training, and procedural controls

· Designs should give visual clues about how to interact with them.^{15, 16}

CONCLUSION:

Patient safety is a serious global public health issue. Improvements in the quality and safety of health care can be achieved by better integrating human factors and systems engineering throughout the various layers and units of healthcare organizations. Human factors and ergonomics provide a ‘tried and true’ framework for building and strengthening that elusive safety culture. This helps to ensure that the system being designed meets its intended purpose and operates in its intended manner.

REFERENCES:

1. WHO Ten facts on patient safety. Available from: URL:http://www.who.int/features/factfiles/patient_safety/patient_safety_facts/en/

2. Woloshynowych M, Rogers S, Taylor-Adams S, Vincent C. The investigation and analysis of critical incidents and adverse events in healthcare. Health Technology Assessment.2005; 9(19), 1–143.

3. Cook R, Rasmussen J. “Going solid”: a model of system dynamics and consequences for patient safety. Quality and Safety in Health Care. 2005 Apr 1; 14(2):130-4.

4. World Alliance For Patient Safety Drafting Group, Sherman H, Castro G, Fletcher M, Hatlie M, Hibbert P, Jakob R, Koss R, Lewalle P, Loeb J, Perneger T. Towards an International Classification for Patient Safety: the conceptual framework. International Journal for Quality in Health Care. 2009 Feb 1; 21(1):2-8.

5. Reason J. Human error: models and management. BMJ. 2000 Mar 18; 320(7237):768.

6. Salvendy G. Handbook of human factors and ergonomics. John Wiley and Sons; 2012 May 24.

7. Wagenaar WA, Hudson PT, Reason JT. Cognitive failures and accidents. Applied Cognitive Psychology. 1990 Jul 1; 4(4):273-94.

8. Patient Safety: The Role of Human Factors and Systems Engineering. PMC 2011 Mar 15.Published in final edited form as:Stud Health Technol Inform. 2010; 153: 23–46.

9. Shojania KG, Duncan BW, McDonald KM, et al. Safe but sound. Patient safety meets evidenced-based medicine. JAMA 2001; 288:508–13.

10. Carayon P, Wetterneck TB, Rivera-Rodriguez AJ, Hundt AS, Hoonakker P, Holden R, Gurses AP. Human factors systems approach to healthcare quality and patient safety. Applied ergonomics. 2014 Jan 31;45(1):14-25

11. UK Health and Safety Executive www.hse.gov.uk/stress

12. Carayon P, Xie A, Kianfar S. Human factors and ergonomics as a patient safety practice. BMJ Qual Saf. 2014 Mar 1; 23(3):196-205.

13. Human factors and safety. Available from URL: http://app.ihi.org/lmsspa/#/6cb1c614-884b-43ef-9abd-d90849f183d4/0d1d53a1-1ec4-4065-8250-56247132fb9e

14. Carayon P, editor. Handbook of human factors and ergonomics in health care and patient safety. CRC Press; 2016 Apr 19.

15. Norris B, Currie L, Lecko C. The importance of applying human factors to nursing practice. Nursing Standard. 2012 Apr 17; 26(32):36-40.

16. Cherns A. The principles of sociotechnical design. Hum Relat 1976; 29:783–92

Received on 21.08.2017 Modified on 11.10.2017

Int. J. Adv. Nur. Management. 2017; 5(4):367-371.

DOI: 10.5958/2454-2652.2017.00079.8