Editing Evidence-based medicine (section)

== Background, history, and definition ==
Medicine has a long history of scientific inquiry into the prevention, diagnosis, and treatment of human disease.<ref>{{cite journal | vauthors = Brater DC, Daly WJ | title = Clinical pharmacology in the Middle Ages: principles that presage the 21st century | journal = Clinical Pharmacology and Therapeutics | volume = 67 | issue = 5 | pages = 447–450 | date = May 2000 | pmid = 10824622 | doi = 10.1067/mcp.2000.106465 | s2cid = 45980791 }}</ref><ref name="pmid11058989">{{cite journal | vauthors = Daly WJ, Brater DC | title = Medieval contributions to the search for truth in clinical medicine | journal = Perspectives in Biology and Medicine | volume = 43 | issue = 4 | pages = 530–540 | year = 2000 | pmid = 11058989 | doi = 10.1353/pbm.2000.0037 | s2cid = 30485275 }}</ref> In the 11th century AD, [[Avicenna]], a Persian physician and philosopher, developed an approach to EBM that was mostly similar to current ideas and practises.<ref>{{cite journal | vauthors = Shoja MM, Rashidi MR, Tubbs RS, Etemadi J, Abbasnejad F, Agutter PS | title = Legacy of Avicenna and evidence-based medicine | journal = International Journal of Cardiology | volume = 150 | issue = 3 | pages = 243–246 | date = August 2011 | pmid = 21093081 | doi = 10.1016/j.ijcard.2010.10.019 }}</ref><ref>{{cite journal | vauthors = Akhondzadeh S | title = Avicenna and evidence based medicine | journal = Avicenna Journal of Medical Biotechnology | volume = 6 | issue = 1 | pages = 1–2 | date = January 2014 | pmid = 24523951 | pmc = 3895573 }}</ref>

The concept of a controlled clinical trial was first described in 1662 by [[Jan Baptist van Helmont]] in reference to the practice of [[bloodletting]].<ref>{{cite book |author=John Baptista Van Helmont |title=Oriatrike, or Physick Refined (English translation of Ortus medicinae) |year=1662 |translator=John Chandler |url=https://wellcomecollection.org/works/jh9aanrn}}</ref> Wrote Van Helmont:{{Citation needed|date=March 2025}}
{{Blockquote
|text=Let us take out of the Hospitals, out of the Camps, or from elsewhere, 200, or 500 poor People, that have fevers or Pleuritis. Let us divide them in Halfes, let us cast lots, that one halfe of them may fall to my share, and the others to yours; I will cure them without blood-letting and sensible evacuation; but you do, as ye know ... we shall see how many Funerals both of us shall have...
}}

The first published report describing the conduct and results of a controlled clinical trial was by [[James Lind]], a Scottish naval surgeon who conducted research on [[scurvy]] during his time aboard [[HMS Salisbury (1746)|HMS ''Salisbury'']] in the [[Channel Fleet]], while patrolling the [[Bay of Biscay]]. Lind divided the sailors participating in his experiment into six groups, so that the effects of various treatments could be fairly compared. Lind found improvement in symptoms and signs of scurvy among the group of men treated with lemons or oranges. He published a treatise describing the results of this experiment in 1753.<ref>{{cite book | vauthors = Lind J |title=Treatise on the scurvy|publisher=Gale Ecco |location=|year=2018 |isbn=978-1-379-46980-3}}</ref>

An early critique of statistical methods in medicine was published in 1835, in Comtes Rendus de l’Académie des Sciences, Paris, by a man referred to as "Mr Civiale".<ref>{{cite journal | vauthors =  | title = Statistical research on conditions caused by calculi by Doctor Civiale. 1835 | journal = International Journal of Epidemiology | volume = 30 | issue = 6 | pages = 1246–1249 | date = December 2001 | pmid = 11821317 | doi = 10.1093/ije/30.6.1246 | url = http://ije.oupjournals.org/cgi/content/full/30/6/1246 | url-status = dead | orig-year = 1835 | doi-access = free | archive-url = https://web.archive.org/web/20050429042527/http://ije.oupjournals.org/cgi/content/full/30/6/1246 | archive-date = 29 April 2005 }}</ref>

In 1990, [[Gordon Guyatt]], then a young internal medicine residency coordinator at [[McMaster University]], introduced a teaching method he initially termed "Scientific Medicine." This approach emphasized applying critical appraisal techniques directly to bedside clinical decision-making, building on the work of his mentor, [[David Sackett]]. However, the concept met resistance from colleagues, as it implied that existing clinical practices lacked scientific rigor, even though this was likely true. To address this, Guyatt rebranded the approach as "Evidence-Based Medicine", a term first formally introduced in a 1991 editorial in the ACP Journal Club. Although the name was coined in 1991, it took several years after and a concerted efforts of many other teams to define the foundations of this method.<ref>{{cite journal |last1=Sur |first1=RL |last2=Dahm |first2=P |title=History of evidence-based medicine. |journal=Indian Journal of Urology |date=October 2011 |volume=27 |issue=4 |pages=487–9 |doi=10.4103/0970-1591.91438 |doi-access=free |pmid=22279315|pmc=3263217 }}</ref><ref>Guyatt GH. Evidence-Based Medicine [editorial]. ACP Journal Club 1991:A-16. (Annals of Internal Medicine; vol. 114, suppl. 2).</ref><ref>{{cite web|url=https://www.ama-assn.org/residents-students/residency/development-evidence-based-medicine-explored-oral-history-video |title= Development of evidence-based medicine explored in oral history video, AMA, Jan 27, 2014|date= 27 January 2014}}</ref><ref>{{cite journal | vauthors = Sackett DL, Rosenberg WM | title = The need for evidence-based medicine | journal = Journal of the Royal Society of Medicine | volume = 88 | issue = 11 | pages = 620–624 | date = November 1995 | pmid = 8544145 | pmc = 1295384 | doi = 10.1177/014107689508801105 }}</ref><ref>{{cite book |location=Cologne, Germany |publisher=Institute for Quality and Efficiency in Health Care (IQWiG) |date=2016 |title=The history of evidence-based medicine |url=https://www.ncbi.nlm.nih.gov/books/NBK390299/ |id=NBK390299}}</ref>

Although more popular in medicine, the concept of "evidence-based" is spreading to other disciplines, such as the humanities, and to languages other than English, albeit at a slower pace.<ref>{{cite journal |last1=Watine |first1=J |title=Translations of the "Evidence-Based Medicine" concept in different languages: is it time for international standardisation? |journal=Clinical Chemistry and Laboratory Medicine |date=September 2010 |volume=48 |issue=9 |pages=1227–8 |doi=10.1515/CCLM.2010.266 |pmid=20618091}}</ref>

=== Clinical decision-making ===
[[Alvan Feinstein]]'s publication of ''Clinical Judgment'' in 1967 focused attention on the role of clinical reasoning and identified biases that can affect it.<ref name="feinstein">{{cite book |author=Alvan R. Feinstein |title=Clinical Judgement |year=1967 |publisher=Williams & Wilkins}}</ref> In 1972, [[Archie Cochrane]] published ''Effectiveness and Efficiency'', which described the lack of controlled trials supporting many practices that had previously been assumed to be effective.<ref name="cochraneal">{{cite book |author=Cochrane A.L. |author-link= Archie Cochrane |title=Effectiveness and Efficiency: Random Reflections on Health Services |year=1972 |publisher=Nuffield Provincial Hospitals Trust}}</ref> In 1973, [[John Wennberg]] began to document wide variations in how physicians practiced.<ref name="wennberg">{{cite journal | vauthors = Wennberg J | title = Small area variations in health care delivery | journal = Science | volume = 182 | issue = 4117 | pages = 1102–1108 | date = December 1973 | pmid = 4750608 | doi = 10.1126/science.182.4117.1102 | s2cid = 43819003 | bibcode = 1973Sci...182.1102W }}</ref> Through the 1980s, [[David M. Eddy]] described errors in clinical reasoning and gaps in evidence.<ref name="eddy2">{{cite book | vauthors = Eddy DM |chapter=18 Probabilistic Reasoning in Clinical Medicine: Problems and Opportunities | veditors = Kahneman D, Slovic P, Tversky A |title=Judgment Under Uncertainty: Heuristics and Biases |chapter-url=https://books.google.com/books?id=_0H8gwj4a1MC&pg=PA249 |date=1982 |publisher=Cambridge University Press |isbn=978-0-521-28414-1 |pages=249–267}}</ref><ref name="eddy3">{{cite journal | vauthors = Eddy DM | title = Clinical policies and the quality of clinical practice | journal = The New England Journal of Medicine | volume = 307 | issue = 6 | pages = 343–347 | date = August 1982 | pmid = 7088099 | doi = 10.1056/nejm198208053070604 }}</ref><ref name="eddy4">{{cite journal | vauthors = Eddy DM | title = Variations in physician practice: the role of uncertainty | journal = Health Affairs | volume = 3 | issue = 2 | pages = 74–89 | year = 1984 | pmid = 6469198 | doi = 10.1377/hlthaff.3.2.74 }}</ref><ref name="eddy5">{{cite journal | vauthors = Eddy DM, Billings J | title = The quality of medical evidence: implications for quality of care | journal = Health Affairs | volume = 7 | issue = 1 | pages = 19–32 | date = 1988 | pmid = 3360391 | doi = 10.1377/hlthaff.7.1.19 | doi-access =  }}</ref> In the mid-1980s, Alvin Feinstein, [[David Sackett]] and others published textbooks on clinical [[epidemiology]], which translated epidemiological methods to physician decision-making.<ref name="feinstein2">{{cite book|author=Feinstein AR|title=Clinical Epidemiology: The Architecture of Clinical Research|date=1985|publisher=W.B. Saunders Company |isbn=978-0-7216-1308-6}}</ref><ref name="sackett">{{cite book | vauthors = Sackett D | veditors = Haynes BR |title=Clinical Epidemiology: How to Do Clinical Practice Research |url=https://books.google.com/books?id=cuvY6TItIwgC&pg=PA59 |year=2006 |publisher=Lippincott Williams & Wilkins |isbn=978-0-7817-4524-6}}</ref> Toward the end of the 1980s, a group at [[RAND]] showed that large proportions of procedures performed by physicians were considered inappropriate even by the standards of their own experts.<ref name="chassin">{{cite journal | vauthors = Chassin MR, Kosecoff J, Solomon DH, Brook RH | title = How coronary angiography is used. Clinical determinants of appropriateness | journal = JAMA | volume = 258 | issue = 18 | pages = 2543–2547 | date = November 1987 | pmid = 3312657 | doi = 10.1001/jama.258.18.2543 }}</ref>

=== Evidence-based guidelines and policies ===
{{Main|Medical guideline}}
David M. Eddy first began to use the term 'evidence-based' in 1987 in workshops and a manual commissioned by the Council of Medical Specialty Societies to teach formal methods for designing clinical practice guidelines. The manual was eventually published by the [[American College of Physicians]].<ref name="eddy1992">{{cite book |author=Eddy DM |title=A Manual for Assessing Health Practices and Designing Practice Policies |publisher=American College of Physicians|date=1992 |isbn=978-0-943126-18-0 }}</ref><ref name="field">{{cite book|author=Institute of Medicine| veditors = Field MJ, Lohr KN |title=Clinical Practice Guidelines: Directions for a New Program |location=Washington, DC|publisher=National Academy of Sciences Press|year=1990|isbn=978-0-309-07666-1|page=32|url= http://www.nap.edu/openbook.php?record_id=1626&page=32 |doi=10.17226/1626|pmid=25144032 |pmc=5310095}}</ref> Eddy first published the term 'evidence-based' in March 1990, in an article in the ''Journal of the American Medical Association ([[JAMA]])'' that laid out the principles of evidence-based guidelines and population-level policies, which Eddy described as "explicitly describing the available evidence that pertains to a policy and tying the policy to evidence instead of standard-of-care practices or the beliefs of experts. The pertinent evidence must be identified, described, and analyzed. The policymakers must determine whether the policy is justified by the evidence. A rationale must be written."<ref name="eddy6" /> He discussed evidence-based policies in several other papers published in ''JAMA'' in the spring of 1990.<ref name="eddy6">{{cite journal | vauthors = Eddy DM | title = Clinical decision making: from theory to practice. Practice policies—guidelines for methods | journal = JAMA | volume = 263 | issue = 13 | pages = 1839–1841 | date = April 1990 | pmid = 2313855 | doi = 10.1001/jama.263.13.1839 }}</ref><ref name="eddy7">{{cite journal | vauthors = Eddy DM | title = Clinical decision making: from theory to practice. Guidelines for policy statements: the explicit approach | journal = JAMA | volume = 263 | issue = 16 | pages = 2239–40, 2243 | date = April 1990 | pmid = 2319689 | doi = 10.1001/jama.1990.03440160101046 }}</ref> Those papers were part of a series of 28 published in ''JAMA'' between 1990 and 1997 on formal methods for designing population-level guidelines and policies.<ref name="eddy8">{{cite book |author=Eddy DM |title=Clinical Decision Making: From Theory to Practice. A Collection of Essays |publisher=American Medical Association |year=1996 |isbn=978-0-7637-0143-7}}</ref>

=== Medical education ===
The term 'evidence-based medicine' was introduced slightly later, in the context of medical education. In the autumn of 1990, [[Gordon Guyatt]] used it in an unpublished description of a program at [[McMaster University]] for prospective or new medical students.<ref name="howick">{{cite book | vauthors = Howick JH |title=The Philosophy of Evidence-based Medicine |publisher=Wiley |page=15 |isbn=978-1-4443-4266-6 |date=23 February 2011}}</ref> Guyatt and others first published the term two years later (1992) to describe a new approach to teaching the practice of medicine.<ref name="Guyatt" />

In 1996, David Sackett and colleagues clarified the definition of this tributary of evidence-based medicine as "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. ... [It] means integrating individual clinical expertise with the best available external clinical evidence from systematic research."<ref name="sackett2">{{cite journal | vauthors = Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS | title = Evidence based medicine: what it is and what it isn't | journal = BMJ | volume = 312 | issue = 7023 | pages = 71–72 | date = January 1996 | pmid = 8555924 | pmc = 2349778 | doi = 10.1136/bmj.312.7023.71 }}</ref> This branch of evidence-based medicine aims to make individual decision making more structured and objective by better reflecting the evidence from research.<ref name="katz">{{cite book | vauthors = Katz DL |title=Clinical Epidemiology & Evidence-Based Medicine: Fundamental Principles of Clinical Reasoning & Research|url=https://archive.org/details/clinicalepidemio0000katz |url-access=registration |year=2001|publisher=Sage|isbn=978-0-7619-1939-1}}</ref><ref name="grobbee">{{cite book | vauthors = Grobbee DE, Hoes AW | title=Clinical Epidemiology: Principles, Methods, and Applications for Clinical Research|year=2009|publisher=Jones & Bartlett Learning| isbn=978-0-7637-5315-3}}</ref> Population-based data are applied to the care of an individual patient,<ref name="doi">{{cite book| vauthors = Doi SA |title=Understanding Evidence in Health Care: Using Clinical Epidemiology|year=2012|publisher=Palgrave Macmillan|location=South Yarra, VIC, Australia|isbn=978-1-4202-5669-7}}</ref> while respecting the fact that practitioners have clinical expertise reflected in effective and efficient diagnosis and thoughtful identification and compassionate use of individual patients' predicaments, rights, and preferences.<ref name=sackett2 />

Between 1993 and 2000, the Evidence-Based Medicine Working Group at McMaster University published the methods to a broad physician audience in a series of 25 "Users' Guides to the Medical Literature" in ''JAMA''. In 1995 Rosenberg and Donald defined individual-level, evidence-based medicine as "the process of finding, appraising, and using contemporaneous research findings as the basis for medical decisions."<ref name="rosenberg2">{{cite journal | vauthors = Rosenberg W, Donald A | title = Evidence based medicine: an approach to clinical problem-solving | journal = BMJ | volume = 310 | issue = 6987 | pages = 1122–1126 | date = April 1995 | pmid = 7742682 | pmc = 2549505 | doi = 10.1136/bmj.310.6987.1122 }}</ref> In 2010, [[Trisha Greenhalgh|Greenhalgh]] used a definition that emphasized quantitative methods: "the use of mathematical estimates of the risk of benefit and harm, derived from high-quality research on population samples, to inform clinical decision-making in the diagnosis, investigation or management of individual patients."<ref name="greenhalgh1">{{cite book| vauthors = Greenhalgh T |author-link=Trisha Greenhalgh|date=2010|title=How to Read a Paper: The Basics of Evidence-Based Medicine | edition = 4th |url=https://archive.org/details/howtoreadpaperba00tgre |url-access=limited |publisher= John Wiley & Sons|page= [https://archive.org/details/howtoreadpaperba00tgre/page/n20 1]|isbn=978-1-4443-9036-0}}</ref><ref name=sackett2 />

The two original definitions{{which|date=June 2017}} highlight important differences in how evidence-based medicine is applied to populations versus individuals. When designing guidelines applied to large groups of people in settings with relatively little opportunity for modification by individual physicians, evidence-based policymaking emphasizes that good evidence should exist to document a test's or treatment's effectiveness.<ref name="Eddy1990">{{cite journal | vauthors = Eddy DM | title = Practice policies: where do they come from? | journal = JAMA | volume = 263 | issue = 9 | pages = 1265, 1269, 1272 passim | date = March 1990 | pmid = 2304243 | doi = 10.1001/jama.263.9.1265 }}</ref> In the setting of individual decision-making, practitioners can be given greater latitude in how they interpret research and combine it with their clinical judgment.<ref name=sackett2 /><ref name="greenhalgh2">{{cite journal | vauthors = Tonelli MR | title = The limits of evidence-based medicine | journal = Respiratory Care | volume = 46 | issue = 12 | pages = 1435–1440 | date = December 2001 | pmid = 11728302 | author-link = Trisha Greenhalgh }}</ref> In 2005, Eddy offered an umbrella definition for the two branches of EBM: "Evidence-based medicine is a set of principles and methods intended to ensure that to the greatest extent possible, medical decisions, guidelines, and other types of policies are based on and consistent with good evidence of effectiveness and benefit."<ref name="eddybmapproach">{{cite journal | vauthors = Eddy DM | title = Evidence-based medicine: a unified approach | journal = Health Affairs | volume = 24 | issue = 1 | pages = 9–17 | date = 2005 | pmid = 15647211 | doi = 10.1377/hlthaff.24.1.9 | doi-access =  }}</ref>

=== Progress ===
In the area of evidence-based guidelines and policies, the explicit insistence on evidence of effectiveness was introduced by the American Cancer Society in 1980.<ref name="guidelines">{{cite journal | vauthors = Eddy D | title = ACS report on the cancer-related health checkup | journal = CA | volume = 30 | issue = 4 | pages = 193–240 | year = 1980 | pmid = 6774802 | doi = 10.3322/canjclin.30.4.194 | s2cid = 221546339 | doi-access =  }}</ref> The U.S. Preventive Services Task Force (USPSTF) began issuing guidelines for preventive interventions based on evidence-based principles in 1984.<ref name="taskforce">{{cite web|url=http://www.uspreventiveservicestaskforce.org/about.htm|title=About the USPSTF|access-date=21 August 2014|archive-url=https://web.archive.org/web/20140815122438/http://www.uspreventiveservicestaskforce.org/about.htm|archive-date=15 August 2014|url-status=dead}}</ref> In 1985, the Blue Cross Blue Shield Association applied strict evidence-based criteria for covering new technologies.<ref name="rettig">{{cite book | vauthors = Rettig RA, Jacobson PD, Farquhar CM, Aubry WM |title=False Hope: Bone Marrow Transplantation for Breast Cancer: Bone Marrow Transplantation for Breast Cancer |url=https://books.google.com/books?id=bbcTZLRRVmoC&pg=PA183 |date=2007 |publisher=Oxford University Press |isbn=978-0-19-974824-2 |pages=183}}</ref> Beginning in 1987, specialty societies such as the American College of Physicians, and voluntary health organizations such as the American Heart Association, wrote many evidence-based guidelines. In 1991, [[Kaiser Permanente]], a managed care organization in the US, began an evidence-based guidelines program.<ref name="kaiserpermanente">{{cite journal | vauthors = Davino-Ramaya C, Krause LK, Robbins CW, Harris JS, Koster M, Chan W, Tom GI | title = Transparency matters: Kaiser Permanente's National Guideline Program methodological processes | journal = The Permanente Journal | volume = 16 | issue = 1 | pages = 55–62 | year = 2012 | pmid = 22529761 | pmc = 3327114 | doi = 10.7812/tpp/11-134 }}</ref> In 1991, Richard Smith wrote an editorial in the ''British Medical Journal'' and introduced the ideas of evidence-based policies in the UK.<ref name=smith>{{cite journal | vauthors = Smith R | title = Where is the wisdom...? | journal = BMJ | volume = 303 | issue = 6806 | pages = 798–799 | date = October 1991 | pmid = 1932964 | pmc = 1671173 | doi = 10.1136/bmj.303.6806.798 }}</ref> In 1993, the Cochrane Collaboration created a network of 13 countries to produce systematic reviews and guidelines.<ref name="cochrane">{{cite web|url=http://www.cochrane.org|title=The Cochrane Collaboration|access-date=21 August 2014}}</ref> In 1997, the US Agency for Healthcare Research and Quality (AHRQ, then known as the Agency for Health Care Policy and Research, or AHCPR) established Evidence-based Practice Centers (EPCs) to produce evidence reports and technology assessments to support the development of guidelines.<ref name="ahrq">{{cite web|url=http://www.ahrq.gov/research/findings/evidence-based-reports/overview/index.html|title=Agency for Health Care Policy and Research|access-date=21 August 2014}}</ref> In the same year, a [[National Guideline Clearinghouse]] that followed the principles of evidence-based policies was created by AHRQ, the AMA, and the American Association of Health Plans (now America's Health Insurance Plans).<ref name="guideline">{{cite web|url=http://www.guideline.gov|title=National Guideline Clearinghouse|access-date=21 August 2014|archive-url=https://web.archive.org/web/20140819030216/http://www.guideline.gov/ |archive-date=19 August 2014|url-status=dead}}</ref> In 1999, the [[National Institute for Health and Care Excellence|National Institute for Clinical Excellence]] (NICE) was created in the UK.<ref name="nice">{{cite web|url=http://www.nice.org.uk|title=National Institute for Health and Care Excellence|access-date=21 August 2014}}</ref>

In the area of medical education, medical schools in Canada, the US, the UK, Australia, and other countries<ref>{{cite journal | vauthors = Ilic D, Maloney S | title = Methods of teaching medical trainees evidence-based medicine: a systematic review | journal = Medical Education | volume = 48 | issue = 2 | pages = 124–135 | date = February 2014 | pmid = 24528395 | doi = 10.1111/medu.12288 | s2cid = 12765787 }}</ref><ref>{{cite journal | vauthors = Maggio LA, Tannery NH, Chen HC, ten Cate O, O'Brien B | title = Evidence-based medicine training in undergraduate medical education: a review and critique of the literature published 2006–2011 | journal = Academic Medicine | volume = 88 | issue = 7 | pages = 1022–1028 | date = July 2013 | pmid = 23702528 | doi = 10.1097/ACM.0b013e3182951959 | doi-access = free }}</ref> now offer programs that teach evidence-based medicine. A 2009 study of UK programs found that more than half of UK medical schools offered some training in evidence-based medicine, although the methods and content varied considerably, and EBM teaching was restricted by lack of curriculum time, trained tutors and teaching materials.<ref name="medteach">{{cite journal | vauthors = Meats E, Heneghan C, Crilly M, Glasziou P | title = Evidence-based medicine teaching in UK medical schools | journal = Medical Teacher | volume = 31 | issue = 4 | pages = 332–337 | date = April 2009 | pmid = 19404893 | doi = 10.1080/01421590802572791 | s2cid = 21133182 }}</ref> Many programs have been developed to help individual physicians gain better access to evidence. For example, UpToDate was created in the early 1990s.<ref name="uptodate">{{cite web|url=http://www.uptodate.com/home |title=UpToDate|access-date=21 August 2014}}</ref> The Cochrane Collaboration began publishing evidence reviews in 1993.<ref name=kaiserpermanente /> In 1995, BMJ Publishing Group launched Clinical Evidence, a 6-monthly periodical that provided brief summaries of the current state of evidence about important clinical questions for clinicians.<ref name="clinicalevidence">{{cite web|url=http://www.clinicalevidence.bmj.com/|title=Clinical Evidence|access-date=21 August 2014|archive-date=20 August 2008|archive-url=https://web.archive.org/web/20080820134338/http://clinicalevidence.bmj.com/|url-status=dead}}</ref>

=== Current practice ===
By 2000, use of the term ''evidence-based'' had extended to other levels of the health care system. An example is evidence-based health services, which seek to increase the competence of health service decision makers and the practice of evidence-based medicine at the organizational or institutional level.<ref name="gray">{{cite book|author=Gray, J. A. Muir|date=2009|title=Evidence-based Health Care & Public Health|publisher=Churchill Livingstone|isbn=978-0-443-10123-6}}</ref>

The multiple tributaries of evidence-based medicine share an emphasis on the importance of incorporating evidence from formal research in medical policies and decisions. However, because they differ on the extent to which they require good evidence of effectiveness before promoting a guideline or payment policy, a distinction is sometimes made between evidence-based medicine and science-based medicine, which also takes into account factors such as prior plausibility and compatibility with established science (as when medical organizations promote controversial treatments such as [[acupuncture]]).<ref name="AAFP2018">{{cite web |title=AAFP promotes acupuncture |publisher=Science-Based Medicine |date=9 October 2018 |url=https://sciencebasedmedicine.org/aafp-promotes-acupuncture/ |access-date=12 January 2019}}</ref>  Differences also exist regarding the extent to which it is feasible to incorporate individual-level information in decisions. Thus, evidence-based guidelines and policies may not readily "hybridise" with experience-based practices orientated towards ethical clinical judgement, and can lead to contradictions, contest, and unintended crises.<ref name=eddy5 /> The most effective "knowledge leaders" (managers and clinical leaders) use a broad range of management knowledge in their decision making, rather than just formal evidence.<ref name=feinstein2 /> Evidence-based guidelines may provide the basis for [[governmentality]] in health care, and consequently play a central role in the governance of contemporary health care systems.<ref name=sackett />