Iatrogenic disease

Iatrogenic illness refers to symptoms induced in a patient by a physician's activity, manner or therapy. It is used especially for a complication of treatment. Iatrogenic diseases may be induced by or attributed to doctors themselves, or the medicines, drugs and treatments they prescribe. Illness and suffering are often inflicted by wrong diagnosis, ignorance or negligence. Improper or excessive medication, spreading of an infection by patients, redundant surgery, and neuroses engendered by a psychiatrist are all examples of iatrogenic diseases.

Nosocomial illness has a similar meaning to iatrogenic and refers in particular to the hospital environment. Nosocomial illness comprises all things that can adversely affect the health of a hospital patient (and are not caused by the original illness), eg infection(s) acquired during the process of receiving health care that was not present during the time of admission. Sometimes called "adverse events" during hospitalization, the main agents of nosocomial illness are operative errors (surgical mistakes), adverse reactions to drugs (mismedication) or medical procedures, and misdiagnosis or bad medical advice. Whilst each of these is amenable to prevention, such mistakes are often considered inevitable under conditions of too few medical staff, who are forced to work too quickly to cope with intense demand.

Hospital illnesses can also can include things like or development of an illness the patient did not have when they arrived. This most commonly happens when serious infections are spread from one patient to the other. While this is sometimes caused by poor hygiene in a hospital, it can also occur when infections exist unknown to hospital personnel, who do not know that radical hygiene is required in a particular case. Associated with the incidence of infections are: the use of invasive techniques, such as catheterization, impaired defences of the body arising from the use of drugs or radiation and increased use of antibiotics. In fact, antibiotics having been deployed so intensively in hospitals over the past four decades that their environment has provided a breeding ground for resistant bacteria. When a patient succumbs to one of these hospital strains, perhaps after surgery or perhaps when debilitated by another illness altogether, drugs that would normally abolish the infection have little or no effect.

The Quality in Australian Healthcare Study (1995) indicated that as many as 18,000 Australians die each year as a result of medical "errors" in hospitals. Put another way, preventable medical error in hospitals is responsible for 11% of all deaths in Australia, which is about 1 of every 9 deaths. A further 50,000 people a year are injured, or permanently disabled. More detailed analysis of just under 2000 cases found that 81.1% either died or were injured as a direct result of "human error". New Zealand figures are very similar.

An article in the Journal of the American Medical Association (2001) estimated up to 250,000 deaths per year in the USA from iatrogenic causes: 12,000 resulting from unnecessary surgery; 7,000 from medication errors in hospitals; 20,000 from other errors in hospitals; 80,000 from infections in hospitals; and 106,000 from "non-error", negative effects of drugs. Collectively this constitutes the third leading cause of death in the USA after deaths from heart disease and cancer. The US Institute of Medicine reported in 2000 that medical mistakes kill from 44,000 to 98,000 hospitalized Americans a year - presumably counting those in the first three "error" categories noted above (ie excluding death due to iatrogenic infections and the negative effects of drugs). Another report drew on studies that examined the records of 30,195 patients and found a 3.7% error rate. Of those injured, 14% died. Researchers concluded that 70% of the errors - and 155,000 deaths - were avoidable. Evidence from other studies indicates that as many as 20% to 30% of patients receive inappropriate care. Another analysis concluded that between 4% and 18% of consecutive patients experience negative effects in outpatient settings, with: 116 million extra physician visits; 77 million extra prescriptions; 17 million emergency department visits; 8 million hospitalizations; 3 million long-term admissions; 199,000 additional deaths; US$ 77 billion in extra costs.

The situation is similar in other developed countries. Medical error is the third most frequent cause of death in Britain after cancer and heart disease, killing up to 40,000 people a year - about four times more than die from all other types of accident. Provisional research figures on hospital mistakes show that a further 280,000 people suffer from non-fatal drug-prescribing errors, overdoses and infections. The victims spend an average of six extra days recovering in hospital, at an annual cost of £730m in England alone.

Another estimate is that 5% of the 8.5 million patients admitted to hospitals in England and Wales each year experience preventable adverse events, leading to an additional three million bed days. About half of the adverse events would have been preventable with current standards of care. More than one million hospital admittances each year in the UK are because of medical errors, incompetence or the side-effects of treatment. Much of the damage is caused by careless or inappropriate prescribing, or overprescribing. This means the doctors rate alongside cancer and heart disease as a major cause of serious illness and death.

A study by research team from University College London (2001) estimated that one in 14 British patients suffers some kind of "adverse event" during hospital stays. One in ten of all hospital patients is harmed by complications, half caused by medical mistakes of some kind, and almost 70,000 a year die partly as a result of such "adverse events".

Nearly 28,000 written complaints are made about aspects of clinical treatment in UK hospitals each year. The National Health System (NHS) pays out around 4 million pounds a year for settlement of clinical negligence claims, and has potential liability of around 2.4 billion pounds for existing and expected claims.

One bacterial strain called methicillin-resistant Staphylococcus aureus thrives because competing bacteria have been killed off by the overuse of antibiotics. It poses a therapeutic challenge in acute-care settings, as well as long-term skilled-nursing facilities. In UK one in 10 patients catch an disease in hospital, and one half of hospital-induced infections are caused by this bacterium. In the UK, over 2000 patients in 99 hospitals were infected in one 12 month period. Other research suggests that as many as one-sixth of patients in Europe's hospitals are only there because they have been made ill by doctors. Hospital acquired infections in the UK are estimated to cost the NHS nearly one billion pounds a year. The most infamous iatrogenic disease is the congenital absence of limbs in the children of mothers who received thalidomide during pregnancy. Medical institutionalization is also a significant contributory ingredient, with hospitals sometimes doing more harm than good. The depersonalization of modern medicine, X-rays, gadgetry, mechanical contrivances and computer diagnosis also facilitate the occurrence of iatrogenic disease. Haemophiliacs are a large proportion of those who have contracted AIDS through hospital transfusions of infected blood. Hepatitis has been another common iatrogenic disease caused by blood transfusions.

About 230,000 Australians admitted to hospital every year due to “medication misadventure”, according to reports from the Australian Commission on Safety and Quality in Health Care (2018).