Editing Confirmation bias (section)

=== Medicine and health ===
Cognitive biases are important variables in clinical decision-making by medical general practitioners (GPs) and medical specialists. Two important ones are confirmation bias and the overlapping availability bias. A GP may make a diagnosis early on during an examination, and then seek confirming evidence rather than falsifying evidence. This cognitive error is partly caused by the availability of evidence about the supposed disorder being diagnosed. For example, the client may have mentioned the disorder, or the GP may have recently read a much-discussed paper about the disorder. The basis of this cognitive shortcut or heuristic (termed anchoring) is that the doctor does not consider multiple possibilities based on evidence, but prematurely latches on (or anchors to) a single cause.<ref>{{Citation | last=Groopman | author-link=Jerome Groopman | first= Jerome | title=How doctor's think | publisher=Melbourne: Scribe Publications | year=2007 | pages=64–66 | isbn=978-1-921215-69-8}}</ref> In emergency medicine, because of time pressure, there is a high density of decision-making, and shortcuts are frequently applied. The potential failure rate of these cognitive decisions needs to be managed by education about the 30 or more cognitive biases that can occur, so as to set in place proper debiasing strategies.<ref name="croskerry">{{Citation | last1=Croskerry | first1=Pat | title=Achieving quality in clinical decision making: Cognitive strategies and detection of bias | journal= Academic Emergency Medicine | date=2002 | volume=9 | issue=11 | pages=1184–1204 | doi=10.1197/aemj.9.11.1184 | pmid=12414468 }}.</ref> Confirmation bias may also cause doctors to perform unnecessary medical procedures due to pressure from adamant patients.<ref name="hospitalbias">{{Citation|last1=Pang |first1=Dominic|last2=Bleetman|first2=Anthony|last3=Bleetman| first3=David|last4=Wynne |first4=Max|title=The foreign body that never was: the effects of confirmation bias|journal=British Journal of Hospital Medicine|date=2 June 2017|volume=78|issue=6|pages=350–351|doi=10.12968/hmed.2017.78.6.350|pmid=28614014}}</ref>

Mental disorders may be prone to misdiagnosis in being based upon observations and self-reporting rather than objective testing. Confirmation bias may play a role when practitioners stick with an early diagnosis.<ref>{{Cite journal| doi = 10.1136/bmjqs-2023-016996| issn = 2044-5423| volume = 33| issue = 10| pages = 663–672| last1 = Bradford| first1 = Andrea| last2 = Meyer| first2 = Ashley N. D.| last3 = Khan| first3 = Sundas| last4 = Giardina| first4 = Traber D.| last5 = Singh| first5 = Hardeep| title = Diagnostic Error in Mental Health: A Review| journal = BMJ Quality & Safety| access-date = 2025-04-13| date = 2024-10-01| url = https://qualitysafety.bmj.com/content/33/10/663| pmid = 38575311| pmc = 11503128}}</ref>

Raymond Nickerson, a psychologist, blames confirmation bias for the ineffective medical procedures that were used for centuries before the [[History of medicine|arrival of scientific medicine]].<ref name ="nickerson"/>{{rp|192}} If a patient recovered, medical authorities counted the treatment as successful, rather than looking for alternative explanations such as that the disease had run its natural course. Biased assimilation is a factor in the modern appeal of [[alternative medicine]], whose proponents are swayed by positive [[anecdotal evidence]] but treat [[scientific evidence]] hyper-critically.<ref>{{Harvnb|Goldacre|2008|p=233}}</ref><ref>{{Citation |last1=Singh |first1=Simon | author-link=Simon Singh |first2=Edzard |last2=Ernst | author-link2=Edzard Ernst |title=Trick or treatment?: Alternative medicine on trial |publisher= Bantam |location=London |year=2008 |isbn=978-0-593-06129-9 |pages=287–288}}</ref><ref>{{Citation |last=Atwood |first=Kimball |year=2004 |title=Naturopathy, pseudoscience, and medicine: Myths and fallacies vs truth |journal=[[Medscape General Medicine]] |volume=6 |issue=1 |page=33|pmc=1140750 |pmid=15208545 }}</ref>

[[Cognitive therapy]] was developed by [[Aaron T. Beck]] in the early 1960s and has become a popular approach.<ref>{{Citation |first1=Michael |last1=Neenan |first2=Windy |last2=Dryden |year=2004 |title=Cognitive therapy: 100 key points and techniques |publisher=Psychology Press |isbn=978-1-58391-858-6 |oclc=474568621 |page=ix}}</ref> According to Beck, biased information processing is a factor in [[depression (mood)|depression]].<ref>{{Citation |first1=Ivy-Marie |last1=Blackburn |first2=Kate M. |last2=Davidson |year=1995 |title=Cognitive therapy for depression & anxiety: a practitioner's guide |publisher=Wiley-Blackwell |isbn=978-0-632-03986-9 |oclc=32699443 |edition=2 |page=19}}</ref> His approach teaches people to treat evidence impartially, rather than selectively reinforcing negative outlooks.<ref name="baron195" /> [[Phobias]] and [[hypochondria]] have also been shown to involve confirmation bias for threatening information.<ref>{{Citation |first1=Allison G. |last1=Harvey |first2=Edward |last2=Watkins |first3= Warren |last3=Mansell |year=2004 |title=Cognitive behavioural processes across psychological disorders: a transdiagnostic approach to research and treatment |publisher=Oxford University Press |isbn=978-0-19-852888-3 |oclc=602015097 |pages=172–173, 176}}</ref>