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Year : 2000  |  Volume : 17  |  Issue : 1  |  Page : 73-78

Evidence-based medicine: The new paradigm of clinical decision making

Department of Urology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India

Correspondence Address:
Santosh Kumar
Department of Urology, JIPMER, Pondicherry - 605 006
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Source of Support: None, Conflict of Interest: None

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Traditional clinical decision making (Opinion-Based Medicine or The Old Paradigm) is based on individual clinical experience. Wide variability and inconsistencies of traditional clinical decision making have been docu­mented. The movement of Evidence-Based Medicine (The New Paradigm) was started in early 1990s to integrate research evidence into clinical decision-making process with the ultimate aim of providing optimum management to patients. This article briefly discusses the shortcom­ings of Opinion-Based Medicine and describes the prin­ciples, methodology, requisite skills and resources, advantages and limitations of Evidence-Based Medicine.

Keywords: Evidence-Based Medicine; Clinical Decision Making; Literature Search; Critical Appraisal.

How to cite this article:
Kumar S. Evidence-based medicine: The new paradigm of clinical decision making. Indian J Urol 2000;17:73-8

How to cite this URL:
Kumar S. Evidence-based medicine: The new paradigm of clinical decision making. Indian J Urol [serial online] 2000 [cited 2023 Feb 5];17:73-8. Available from:

   Introduction Top

Traditional clinical decision making (Opinion-Based Medicine or The Old Paradigm) is based on individual clinical experience. [1],[2],[3] Studies have documented wide vari­ability and inconsistencies of traditional clinical decision making. [4],[5],[6] This is largely due to the formidable task of keeping up with fast-growing medical literature and re­sulting gap between medical research and clinical prac­tice. [7],[8],[9] The movement of Evidence-Based Medicine (The New Paradigm) was started in early 1990s to integrate research evidence into clinical decision making process with the ultimate aim of providing optimum management to patients. [7],[10],[11] This article defines Evidence-Based Medi­cine and discusses its methodology. Resources and skills necessary to practise Evidence-Based Medicine and its advantages and limitations are also described.

   Opinion-Based Medicine (The Old Paradigm) Top

In Opinion-Based Medicine, clinical decisions are made by the seniormost clinician of the group [Figure 1]. The senior clinician uses personal experience, clinical intuition and anecdotal evidence for decision making. This traditional clinical decision making is based on the following assumptions: [1]

  1. Individual clinical experience provides the founda­tion for diagnosis, treatment and prognosis. The authority of an opinion is directly related to the volume of clinical experience.
  2. Clinical experience and judgement enables clinicians to evaluate new tests and procedures.

Studies in 1980s revealed wide geographical variations in the rates of prostatectomies, [4] carotid endarterectomies, tonsillectomies and hysterectomies. [5],[6] As it could not be explained by the rates of disease occurrence, it obviously reflected inconsistencies and shortcomings of the clinical decision making of Opinion-Based Medicine. The docu­mentation of the wide variability of clinical practice was one of the factors that prompted the evolution of Evidence­Based Medicine in the early 1990s at McMaster Univer­sity in Hamilton, Ontario. [7],[10],[11]

   Evidence-Based Medicine (The New Paradigm) Top

Evidence-Based Medicine uses scientific evidence for clinical decision making with the ultimate aim of provi­ding optimum management to patients. It is defined as the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. [7] Evidence-Based Medicine rests on the follow­ing assumptions: [1]

  1. Systematic, reproducible attempts of research stud­ies to record outcomes increase the certainty of diagnosis, treatment and validity of diagnostic tests.
  2. Formal rules of scientific evidence [7] are essential to evaluate the literature on diagnosis, treatment and prog­nosis. These rules are embodied in the discipline of clini­cal epidemiology. [12]

The basic principles of Evidence-Based Medicine in­clude the following: [9]

  1. Clinical decisions should be based on the best avail­able scientific evidence.
  2. Clinical problems should determine the type of evi­dence to be sought.
  3. The best evidence is identified by using epidemio­logical and biostatistical concepts.
  4. Conclusions derived from the critical appraisal of evidence should be used for the management of patients.
  5. Clinical performance should be constantly evaluated.

Evidence-Based Medicine does not prescribe the types of diagnostic or intervention procedures that clinicians should use in practice. It is a toolbox consisting primarily of methods designed to integrate research study evidence into the clinical reasoning process. [13]

   The Methodology of Evidence-Based Medicine Top

The methodology of Evidence-Based Medicine comprises the following steps: [11]

  1. Formulation of clinical questions from patient prob­lems.
  2. Performing an electronic search of literature for rele­vant evidence.
  3. Evaluation of evidence for its validity and useful­ness.
  4. Use of valid and applicable evidence in clinical prac­tice.

These steps of clinical decision making in Evidence­Based Medicine are depicted in [Figure 2].

Evidence-Based Medicine serves as a bridge between medical research and clinical practice [Figure 3]. In Opin­ion-Based Medicine a gap remains between medical re­search and clinical practice because it is a formidable task to keep up with the medical literature due to the following barriers: [8]

  1. There is continuing rapid proliferation of medical lite­rature.
  2. Journal articles are widely disseminated and poorly-­organised.
  3. There is a lack of time necessary for keeping up to date.
  4. Textbooks become quickly outdated.
  5. Most of the available information is unsuitable for clinical decision-making due to lack of validity and appli­cability.

The methods of keeping up with medical literature dif­fer in Opinion-Based Medicine and Evidence-Based Medi­cine [Table 1].

1. Formulation of Clinical Questions from Patient Problems.

A clinical question is formulated around a clinical task in such a manner that the question can be answered through a systematic search for relevant evidence. Clinical tasks include making a differential diagnosis, selecting diag­nostic tests, predicting prognosis, selecting therapy and determining etiology of disease. Clinical questions should be specific and should include the type of patient, the clini­cal intervention and the clinical outcome of interest. [14]

2. Performing an Electronic Search of Literature for Relevant Clinical Articles.

An electronic search of Medline is carried out using CD-ROM or the Internet. [15],[16],[17],[18],[19],[20] If the search is confined to only Medline, as many as 50% of relevant articles may be missed. Literature search can be improved by improving search strategy and by using other databases such as Embase and Controlled Clinical Trials Registry of The Cochrane Collaboration.

3. Evaluation of Evidence for its Validity and Appli­cability.

Most of the published articles either contain methodological flaws or lack clinical applicability. Hence, the qua­lity of evidence is evaluated or critically appraised using criteria recommended in the Users' Guides to the Medical Literature in JAMA [21],[22],[23],[24],[25],[26],[27] and other publications. [7] By criti­cal appraisal, articles providing valid, important and ap­plicable evidence are selected [Figure 4].

For critical appraisal of different types of studies, "hi­erarchy of evidence" [28] is used in which the highest weight is assigned to systematic reviews and meta-analyses and the lowest weight is assigned to case reports [Table 2].

4. Use of Valid and Applicable Evidence in Clinical Practice.

Evidence which has been identified as valid and appli­cable is used to solve patient problems. This evidence can be stored for future use also.

   Skills Necessary for Evidence-Based Medicine Top

The practice of Evidence-Based Medicine needs the following skills:

  1. Ability to use computers.

  2. Ability to use the Internet.

  3. Ability to perform efficient medical literature search.

  4. Ability to critically appraise journal articles.

    a) Ability to evaluate research designs.

    b) Ability to evaluate statistics in an article.

    c) Ability to interpret research study results.

  5. Ability to make recommendations based on the strength of evidence.

   Resources Necessary for Evidence-Based Medicine Top

Following resources are necessary for the practice of Evidence-Based Medicine:

  1. Round-the-clock access to a computer with a CD­ ROM drive, Internet connection and a printer.
  2. Medline and other databases on CD-ROM.
  3. Evidence-Based Medicine textbooks and journals.

   Advantages of Evidence-Based Medicine Top

The advantages of Evidence-Based Medicine include the following: [11]

  1. It helps in providing optimum management to pa­tients.
  2. It promotes self-directed learning.
  3. It encourages research in areas where scientific evi­dence is lacking.

   Limitations of Evidence-Based Medicine Top

The limitations of Evidence-Based Medicine include the following: [11]

  1. The resources necessary for the practice of Evidence­Based Medicine are expensive.
  2. Learning and practising Evidence-Based Medicine are time consuming.
  3. Randomised controlled trials may not be available in many surgical fields.
  4. Evidence-Based Medicine may be perceived as a threat by authoritarian clinicians.

   References Top

1.Evidence-Based Working Group. Evidence-Based medicine: A new approach to teaching the practice of medicine. JAMA 1992: 268: 2420-2425.  Back to cited text no. 1    
2.Fabian TC. Evidence-Based medicine in trauma care: Whither goest thou? Journal of Trauma 1999; 47: 225-232.  Back to cited text no. 2    
3.Grimes DA. Introducing evidence-based medicine into a depart­ment of obstetrics and gynaecology. Obstetrics & Gynaecology 1995; 86: 451-457.  Back to cited text no. 3    
4.Wenneberg JE, Mulley AG Jr, Hanley D, et al. An assessment of prostatectomy for benign urinary tract obstruction: Geographic vari­ations and the evaluation of medical care outcomes. JAMA 1988; 259:3027.  Back to cited text no. 4    
5.McPherson K, Wenneberg JE, Hovind OB et al. Small area varia­tions in the use of common surgical procedures: An international comparison of New England, England and Norway. N Engl J Med 1982;307:1310.  Back to cited text no. 5    
6.Eddy DM. Clinical Decision Making: From Theory to Practice - A collection of Essays from JAMA. Boston: Jones & Bartlett Pub­lishers, 1996.  Back to cited text no. 6    
7.Sackett DL, Richardson WS, Rosenberg W, Haynes RB. Evidence­Based Medicine: How to Practise and Teach EBM. New York: Churchill Livingstone, 1997.  Back to cited text no. 7    
8.Covell DG, Uman GC, Manning PR. Information needs in office practice: Are they being met? Ann Intern Med 1985; 103: 596-599.  Back to cited text no. 8    
9.Davidoff F, Haynes RB, Sackett DL, Smith R. Evidence-based medi­cine. BMJ 1995: 310: 1085-1086.  Back to cited text no. 9    
10.Sackett DL. Rosenberg WM, Gray JA. Haynes RB, Richardson WS. Evidence-based medicine: What is it and what it is not? BMJ 1996; 312: 71-72.  Back to cited text no. 10    
11.Rosenberg W, Donald A. Evidence-based medicine: An approach to clinical problem-solving. BMJ 1995: 310: 1122-1126.  Back to cited text no. 11    
12.Sackett DL. Haynes RB, Guyatt GH. Tugwell P. Clinical Epidemi­ology: A Basic Science for Clinical Medicine (2nd edition). Bos­ton: Little, Brown & Co., 1991.  Back to cited text no. 12    
13.Tickle-Degnen L. Organising, evaluating and using evidence in oc­cupational therapy practice. The American Journal of Occupational Therapy 1999; 53: 537-539.  Back to cited text no. 13    
14.Richardson W. Wilson M, Nishikawa R Hayward R. The well-built clinical question: A key to evidence-based decisions. ACP J Club 1995; 123: A12-A13.  Back to cited text no. 14    
15.Lindberg DAB. Siegel ER, Rapp BA. Wallingford KT, Wilson SR. Use of Medline by physicians for clinical problem solving. JAMA 1993; 269: 3124-3129.  Back to cited text no. 15    
16.Glowniak JV. Bushway MK. Computer networks as a medical re­source: Accessing and using the Internet. JAMA 1994; 271: 1934­-1939.  Back to cited text no. 16    
17.Editorial. Information technology, the Internet and urology. British Journal of Urology 1997; 80 (Suppl 3): 1.  Back to cited text no. 17    
18.Kumar S. How to search literature. Indian Journal of Urology 1993; 10: 33-44.  Back to cited text no. 18    
19.Anand I, Srinivas M, Hemal AK. Urology on the Internet: Introduction and update. Ind J Urol 2000; 16: 140-148.  Back to cited text no. 19    
20.Mallikarjuna Reddy N. Internet for the urologist made easy. Ind J Urol 2000; 16: 149-151.  Back to cited text no. 20    
21.Oxman AD, Sackett DL, Guyatt GH. User's guides to the medical literature: I. How to get started. JAMA 1993; 270: 2093-2095.  Back to cited text no. 21    
22.Guyatt GH, Sackett DL, Cook DJ. User's guides to the medical literature: II. How to use an article about therapy or prevention. A. Are the results of the study valid? JAMA 1993; 270: 2598-2601.  Back to cited text no. 22    
23.Guyatt GH, Sackett DL, Cook DJ. Users' guides to the medical literature: II. How to use an article about therapy or prevention. B. What were the results and will they help me in caring for my pa­tients? JAMA 1994; 271: 59-63.  Back to cited text no. 23    
24.Jaeschke R, Guyatt GH, Sackett DL. Users' guides to the medical literature: III. How to use an article about a diagnostic test. A. Are the results of the study valid? JAMA 1994; 271: 389-391.  Back to cited text no. 24    
25.Jaeschke R, Guyatt GH, Sackett DL. Users' guides to the medical literature: III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? JAMA 1994; 271: 703-707.  Back to cited text no. 25    
26.Levine M, Walter S, Lee H, Haines T, Holbrook A, Moyer V. Users' guides to the medical literature: IV. How to use an article about harm. JAMA 1994; 271: 1615-1619.  Back to cited text no. 26    
27.Laupacis A, Wells G, Richardson WS, Tu.-well P. Users' guides to the medical literature: V. How to use an article about prognosis. JAMA 1994; 271: 234-237.  Back to cited text no. 27    
28.Guyatt GH, Sackett DL, Sinclair JC, Hayward R, Crook DJ, Crook RJ. Users' guides to the medical literture: IX. A method for grading health care recommendations. JAMA 1995; 274. 1800-1804.  Back to cited text no. 28    


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2]


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