doi:10.1111/codi.12827
Special article
It’s got four wheels but is it a ‘Ferrari’ or a ‘Fiat Bambino’? A critical reappraisal of evidence-based medicine
It is obviously the case [1–3] that evidence-based medicine (EBM) relies on facts, whereby experimental evidence prevails over other knowledge. Thus, scientific conclusions, for example from randomized controlled trials (RCTs), can be reached regardless of theory, artefacts or observer-dependent bias. While extremely valuable and helpful in many clinical situations, EBM has its weaknesses. The definition of ‘evidence’ may be ambiguous and can exclude important information. In EBM various degrees of ‘evidence’ are classified according to the method used for its collection. Some types of study, such as a RCT, are generally believed to be less ‘vulnerable’ to error and are therefore accepted as being of ‘higher quality’, but ironically RCTs and meta-analyses have never been scientifically proven to be more reliable than other methods of research. The definition of ‘high-quality evidence’ may exclude the information necessary to address many medical questions. Thus EBM does not provide any means of integrating other important forms of medical knowledge such as may come from clinical experience or the individual patient. It is interesting to note that the concept of EBM is not ‘evidence-based’ and has never been found to meet its own empirical tests for evaluating its effectiveness. If we consider that the aim of EBM should be the optimization of medical care by basing decisions on ‘statistically valid’ clinical studies, it is a paradox that there is no scientific ‘evidence’, as defined by EBM, that meets its own criteria. It may be inappropriate to apply EBM to individual patients because of differences in clinical circumstances and individual laboratory data. Many diseases are rare, and their variants, which may include many subsets of patients, will always be beyond ‘evidence’. This difficulty may also apply to common conditions such as constipation, where evidence cannot be applied to each individual owing to the heterogeneity of the disorder. For example, such patients can be divided according to type, age, gender, parity, concomitant disease etc. There is the danger that EBM may fracture the doctor–patient relationship, which is one of the keystones of care, thus limiting the right of the patient to receive the best treatment for his or her particular pathology. It is of further concern that EBM might be used indiscriminately by hospital managers as a powerful and
186
dangerous weapon to reduce health-care costs. They might ask ‘Are we sure that an expensive Whipple procedure for pancreatic cancer translates into a real benefit for the patient? Is survival prolonged? What is the evidence base?’. Yet, if medically indicated, wouldn’t we all offer it to our patients, because the operation can indeed help some, albeit a few? It is also the case that EBM applied indiscriminately could dramatically increase the cost of health care, for example if it were ‘proven’ by the evidence that an unnecessarily expensive therapy was slightly more effective than another effective, yet cheaper, treatment. Not all scientific evidence is made accessible to the public, and this factor can strongly limit the effectiveness of any approach. The most obvious bias is the frequent failure to publish negative results, especially in the case of commercially sponsored clinical trials [4]. Another factor is the type of trial, whereby those that are considered ‘gold standard’, such as a large RCT, may be very expensive so the degree of funding can itself influence what gets investigated and published. Evidence-based medicine has different grades of ‘evidence’ (I to III in the USA; A to D in the UK) and ‘recommendations’ (A to D) [5]. Effectively, saying that for a certain procedure ‘there is EBM’ without necessarily taking into any account whether the evidence or recommendations, adds up to no more than saying that all cars have four wheels, ignoring whether they are Ferraris or Fiat Bambinos. Used correctly, EBM is extremely valuable in clinical practice, but when applied blindly and in ignorance of the specific clinical context it may be misleading and even incorrect.
Luigi Basso*, Luciano Izzo† and Andrea Giuliani‡ *‘Sapienza’ University of Rome, Rome, Italy; †Department of Surgery ‘Pietro Valdoni’, Rome, Italy and ‡Policlinico ‘Umberto I, Rome, Italy
References 1 Wilson K. Evidence-based medicine. The good the bad and the ugly. A clinician’s perspective. J Eval Clin Pract 2010; 16: 398–400. 2 Kral JG, Dixon JB, Horber FF et al. Flaws in methods of evidence-based medicine may adversely affect public health directives. Surgery 2005; 137: 279–84.
Colorectal Disease ª 2015 The Association of Coloproctology of Great Britain and Ireland. 17, 186–187
A critical reappraisal of evidence-based medicine
3 Cohen AM, Hersh WR. Criticisms of evidence-based medicine. Evid Based Cardiovasc Med 2004; 8: 197–8. 4 King RT Jr. Bitter pill: how a drug firm paid for university study, then undermined it. Wall St J 1996; Apr 12: 1, 6.
5 American College of Gastroenterology Chronic Constipation Task Force. An evidence-based approach to the management of chronic constipation in North America. Am J Gastroenterol 2005; 100: S1–4.
Colorectal Disease ª 2015 The Association of Coloproctology of Great Britain and Ireland. 17, 186–187
187
Special article
It’s got four wheels but is it a ‘Ferrari’ or a ‘Fiat Bambino’? A critical reappraisal of evidence-based medicine
It is obviously the case [1–3] that evidence-based medicine (EBM) relies on facts, whereby experimental evidence prevails over other knowledge. Thus, scientific conclusions, for example from randomized controlled trials (RCTs), can be reached regardless of theory, artefacts or observer-dependent bias. While extremely valuable and helpful in many clinical situations, EBM has its weaknesses. The definition of ‘evidence’ may be ambiguous and can exclude important information. In EBM various degrees of ‘evidence’ are classified according to the method used for its collection. Some types of study, such as a RCT, are generally believed to be less ‘vulnerable’ to error and are therefore accepted as being of ‘higher quality’, but ironically RCTs and meta-analyses have never been scientifically proven to be more reliable than other methods of research. The definition of ‘high-quality evidence’ may exclude the information necessary to address many medical questions. Thus EBM does not provide any means of integrating other important forms of medical knowledge such as may come from clinical experience or the individual patient. It is interesting to note that the concept of EBM is not ‘evidence-based’ and has never been found to meet its own empirical tests for evaluating its effectiveness. If we consider that the aim of EBM should be the optimization of medical care by basing decisions on ‘statistically valid’ clinical studies, it is a paradox that there is no scientific ‘evidence’, as defined by EBM, that meets its own criteria. It may be inappropriate to apply EBM to individual patients because of differences in clinical circumstances and individual laboratory data. Many diseases are rare, and their variants, which may include many subsets of patients, will always be beyond ‘evidence’. This difficulty may also apply to common conditions such as constipation, where evidence cannot be applied to each individual owing to the heterogeneity of the disorder. For example, such patients can be divided according to type, age, gender, parity, concomitant disease etc. There is the danger that EBM may fracture the doctor–patient relationship, which is one of the keystones of care, thus limiting the right of the patient to receive the best treatment for his or her particular pathology. It is of further concern that EBM might be used indiscriminately by hospital managers as a powerful and
186
dangerous weapon to reduce health-care costs. They might ask ‘Are we sure that an expensive Whipple procedure for pancreatic cancer translates into a real benefit for the patient? Is survival prolonged? What is the evidence base?’. Yet, if medically indicated, wouldn’t we all offer it to our patients, because the operation can indeed help some, albeit a few? It is also the case that EBM applied indiscriminately could dramatically increase the cost of health care, for example if it were ‘proven’ by the evidence that an unnecessarily expensive therapy was slightly more effective than another effective, yet cheaper, treatment. Not all scientific evidence is made accessible to the public, and this factor can strongly limit the effectiveness of any approach. The most obvious bias is the frequent failure to publish negative results, especially in the case of commercially sponsored clinical trials [4]. Another factor is the type of trial, whereby those that are considered ‘gold standard’, such as a large RCT, may be very expensive so the degree of funding can itself influence what gets investigated and published. Evidence-based medicine has different grades of ‘evidence’ (I to III in the USA; A to D in the UK) and ‘recommendations’ (A to D) [5]. Effectively, saying that for a certain procedure ‘there is EBM’ without necessarily taking into any account whether the evidence or recommendations, adds up to no more than saying that all cars have four wheels, ignoring whether they are Ferraris or Fiat Bambinos. Used correctly, EBM is extremely valuable in clinical practice, but when applied blindly and in ignorance of the specific clinical context it may be misleading and even incorrect.
Luigi Basso*, Luciano Izzo† and Andrea Giuliani‡ *‘Sapienza’ University of Rome, Rome, Italy; †Department of Surgery ‘Pietro Valdoni’, Rome, Italy and ‡Policlinico ‘Umberto I, Rome, Italy
References 1 Wilson K. Evidence-based medicine. The good the bad and the ugly. A clinician’s perspective. J Eval Clin Pract 2010; 16: 398–400. 2 Kral JG, Dixon JB, Horber FF et al. Flaws in methods of evidence-based medicine may adversely affect public health directives. Surgery 2005; 137: 279–84.
Colorectal Disease ª 2015 The Association of Coloproctology of Great Britain and Ireland. 17, 186–187
A critical reappraisal of evidence-based medicine
3 Cohen AM, Hersh WR. Criticisms of evidence-based medicine. Evid Based Cardiovasc Med 2004; 8: 197–8. 4 King RT Jr. Bitter pill: how a drug firm paid for university study, then undermined it. Wall St J 1996; Apr 12: 1, 6.
5 American College of Gastroenterology Chronic Constipation Task Force. An evidence-based approach to the management of chronic constipation in North America. Am J Gastroenterol 2005; 100: S1–4.
Colorectal Disease ª 2015 The Association of Coloproctology of Great Britain and Ireland. 17, 186–187
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![[Laughter is the best medicine - but it has its risks!].](/assets/img/hold.png)
