Part of the University of Adelaide campus at North Terrace. (View of Eastern side of the Mitchell Building.) (Photo credit: Wikipedia)

This is a possible case of copyright infringement but I find it hard to believe that it is not considered as fair use and of justifiable value to the public. Due acknowledgement is made to the author and a source reference supplied here.

This extract sums up the need for publishing this here –

“The current high rate of adverse events has recently come to public light with the publishing of large studies in Australia and the United States of America (USA). So dramatic were the results of the USA study that it led to a presidential dedication to implement a program aimed at decreasing medical errors by 50% in the next 5 years from the year 2000 [5] .”

Michael Edmonds
This article was written by Michael Edmonds during his PhD studies in the Health Informatics Unit, Faculty of Health Sciences, University of Adelaide, circa 2005.

Definition
An adverse event is defined as an “injury resulting from a medical intervention, not the underlying condition of the patient” [1] , and is also referred to as iatrogenic injury, which has been defined as “unintended or unintentional harm or suffering arising from any aspect of health care management” [2] . An adverse event is preventable if it is due to “an error in management due to failure to follow accepted practice at an individual or system level”, where accepted practice is “the current level of expected performance for the average medical practitioner or system that manages the condition in question” [3] .

It has long been recognised that adverse events pose a threat to the safety of patients [4] . This became a prominent issue in the Californian litigation crisis of the early 1970s when an upsurge in litigation cases spurred an investigation that showed that 4.6% of all admissions were associated with a “potentially compensible event” [2] . The current high rate of adverse events has recently come to public light with the publishing of large studies in Australia and the United States of America (USA). So dramatic were the results of the USA study that it led to a presidential dedication to implement a program aimed at decreasing medical errors by 50% in the next 5 years from the year 2000 [5] .

Adverse event data has not been studied or published in the past for many reasons. Adverse events in medicine were never reported systematically, like aviation accidents or motor vehicle accidents, and the scope of the problem has never been previously defined. Medical culture also urges the health care professional to strive for error-free practice. Making an error is seen as a failure of character and there is a reluctance to report adverse events for fear of individual blame and litigation [3] . Other reasons that have been suggested include that it is difficult to access confidential patient files, and that most errors arising from sub-standard performance are believed to be self-regulated within the profession. The changing role of the patient in relation to the doctor is also a factor, with the better informed patient now having the social power to ask about error and failure. Progress in medical technology means that policy and management struggle to maintain protocols and safeguards to keep pace with new advances [2] .

Adverse Event Study Data
Current data show that there is at least a twenty-fold greater danger of dying from just being in hospital than being in traffic or flying in a commercial plane, and that being in hospital is only ten times less dangerous per hour of exposure than parachute jumping [2] . Between 44,000 – 98,000 deaths are attributable to medical error alone in the USA [1] , more than car accidents, breast cancer or AIDS; the situation is equivalent to a fully laden 747 commercial airliner crashing every one and a half to four days. The actual chance of dying in a domestic jet flight in the USA is one in 8 million, equivalent to flying in a jet 24 hours a day for 438 years before being involved in a fatal crash. Medical errors, unfortunately, are not reported systematically like airline crashes as the events occur one-by-one over many locations. Serious injury is not an everyday occurrence for those involved, giving the appearance of each being an isolated and unusual event [4] . Studies such as those performed in the USA , Australia and New Zealand that pool adverse event data from a large source over a period of time can detect events that may seem insignificant of themselves, but when aggregated, reveal a pattern. Identifying these patterns can hopefully lead to improvements in the system to decrease the likelihood of similar events in the future.

A report prepared for the Department of Health in the UK [6] this year indicated that an adverse event was associated with 10% of admissions, with over 850,000 events per year, costing more than £2 billion per year in direct health care costs. In one year, error involving medical devices led to death or serious injury in 400 people, 10,000 patients had serious adverse events involving medication, and the National Health Service received 28,000 written complaints about clinical treatment in hospital. The cost of hospital-acquired infection was over £1 billion in direct health care costs alone, of which 15% were considered to be preventable. Clinical negligence claims currently amount to £400 million annually, with an estimated potential liability of £2.4 billion in existing and expected claims.

Similar patterns were found in the USA , with the release of a 1999 report analysing two medical error studies [1] . Analysis of the Harvard Medical Practice study of 1984 medical records, and the Colorado/Utah study of 1992 records showed adverse events to have been associated with 3.7% and 2.9% of admissions respectively. Adverse events in the Harvard Medical Practice study lead to death in 13.6% of the cases, and permanent disabling injury in 2.6%. Peer review indicated that 58% of these events were preventable, and 27.6% were due to negligence. The Colorado/Utah study showed a mortality rate of 8.8%, with 53% of the adverse events being preventable, and 29.2% being due to negligence. Most common events were medication errors, technical errors, diagnostic errors and failure to prevent injury. Different diseases and causes of death were associated with errors at different stages of care. For instance, death due to myocardial infarction was most commonly associated with management errors, whereas death due to cerebrovascular accidents was mainly due to diagnostic errors, and death due to pneumonia showed errors in both of these areas. This report estimated that the total cost of preventable adverse events is between $17 billion-$29 billion, with direct health care costs accounting for over half.

Results from the Quality in Australian Health Care Study [3] of 1995 show similar results. Adverse events were associated with 16.6% of admissions, with approximately half leading to the admission, and half occurring during the admission. This was associated with mortality in 4.9% of events, or 0.5% of admissions, and permanent disability in 13.7% of events, or in 1% of admissions. Severity of adverse event consequences increased with age, with higher rates of mortality and serious disability in the elderly. Of all adverse events, 51% were deemed to be highly preventable. Adverse events associated with hospital admissions alone were estimated to have accounted for 3.3 million bed days in 1992, of which 1.7 million were considered preventable. This accounted for 8% of all hospital bed days in Australia at a 1992 cost of over $2.2 billion, with over $1.1 billion being preventable [2] . If costs arising from other sources such as mental health institutions, nursing homes, day surgeries, domiciliary care, GP and specialist rooms, and hospital emergency departments were included, the preventable cost of adverse events may be as much as $2 billion annually, or 5% of the $40 billion spent each year on health care. In addition, costs arising from legal expenses and compensation for medical error currently total $400 million per year, which consumes a further 1% of the health budget.

There are many other costs that arise from adverse events in the medical system apart from direct medical and legal costs. It is estimated that for every dollar spent on medication another dollar is spent to treat the new health problems caused by the medication [1] . Indirect costs to health care are made up of increased insurance premiums, lost opportunity costs, and, importantly, human costs to both patients and health care professionals. The cost to the patient comes in the form of increased pain, disability, psychological trauma, loss of trust in the health care system, loss of independence and loss of functionality and productivity. Human costs to health care professionals include a loss of morale and confidence, depression, stress, and feelings of frustration, shame, guilt and inadequacy. There is also an indirect loss to society in the decreased productivity of patients who have suffered a serious adverse event.
Types of Error
Any system or organisation, such as the health care system, is a “complex interaction between human behaviour, technological aspects of the system, socio-cultural factors and a range of organisational or procedural weaknesses” [6] , any of which may lead to error. Error has been classified into many different categories, with overlap between human and system causes [7] . System error tends to be a “latent” condition, where an environmental, management or work-condition factor leads to circumstances in which it is easy to make mistakes. Examples are poor management decisions, attitude of the corporate culture, lack of resources and organisational processes leading to staff fatigue or inexperienced staff on duty, time pressures and inadequate equipment. This can produce an environment in which individuals are more likely to make a mistake, or to violation-producing conditions, where an individual has little choice but to violate protocol. Human error tends to manifest as “active failures” (unsafe acts by individuals). This includes knowledge-based errors, rule-based errors, skill-based errors, such as slips or lapses, technical errors and violations. Latent conditions produce the environment in which active failures will lead adverse effects. Addressing only the active failures will lead to an accumulation of latent conditions, and an inevitable error will ultimately occur, completing the cascade and resulting, potentially or actually, in a tragic outcome.

A system, or organisation, is a set of interdependent elements interacting to achieve a common aim, where the elements are both human and non-human, such as equipment and technology [1] . Organisations may implement systemic defences against error, either hard defences, such as physical containment, automation and engineered features, or soft defences such as procedures, protocols and guidelines. The model for error suggested by James Reason uses Swiss cheese as an analogy. The holes in defence mechanisms due to latent conditions and active failures are always changing, and serious danger develops when these holes happen to line up (see figure) [7] .

Reason’s Swiss Cheese model. When the holes in defences due to latent conditions and active failures line up, error will occur.

Health care is particularly at risk of error due to the increasing complexity and role of new technology and high-risk procedures. The serious consequences of error make it all the more important to focus on reducing the incidence of adverse events, especially in Australia where the ageing population is more susceptible. A focus on the root cause of the problems, and not the immediate event, will lead to a reduction in the current unacceptable rate of iatrogenic injury.
References

1. Kohn L, Corrigan J, Donaldson M. To Err is Human: building a safer health system . Washington, D.C.: National Academy Press, 1999.
2. Australian Patient Safety Foundation. Iatrogenic Injury in Australia: Department of Health and Aged Care, 2000.
3. Wilson RM, Runciman WB, Gibberd RW, Harrison BT, Newby L, Hamilton JD. The Quality in Australian Health Care Study. Med J Aust 1995;163(9):458-71.
4. Leape LL. Error in medicine. JAMA 1994;272(23):1851-7.
5. Press Secretary. Clinton-Gore administration announces new actions to improve patient safety and assure health care quality: The Press Secretary, The White House, 2000.
6. Department of Health. An organisation with a memory. London: Department of Health, 2000.
7. Reason J. Human error: models and management. BMJ 2000;320(7237):768-70.

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