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doi:10.1111/jpc.12800
REVIEW ARTICLE
Evidence-based medicine: What has happened in the past 50 years? Craig Mellis Central Clinical School, University of Sydney, Sydney, New South Wales, Australia
Abstract: Although the phrase ‘evidence-based medicine’ (EBM) was used for the first time in the medical literature less than 25 years ago, the history of EBM goes back for centuries. What is remarkable is how popular and how globally accepted the EBM movement has become in such a short time. Many famous, past clinicians have played major roles in the disciplines that preceded EBM, particularly ‘clinical epidemiology’. It soon became clear to the early EBM champions that ‘evidence’ was only part of the clinical decision-making process. Consequently, both clinical expertise and the patient’s values and preferences were rapidly incorporated into the concept we now know as ‘EBM’. The current need for high-quality, easily accessible ‘evidence-based summaries’ for busy clinicians is now apparent, as traditional EBM requires both considerable time and skill. Consequently, there is a progressive move away from the primary literature (such as randomised controlled trials) to systematic reviews and other ‘evidence-based summaries’. The future of EBM will almost certainly involve widespread utilisation of ‘clinical (computer)based decision support systems’. Key words:
clinical epidemiology; evidence based medicine; general paediatrics; history.
Introduction Enter the phrase ‘evidence-based medicine’ (EBM) into ‘Google’ and you will get over 60 million results; try ‘EBM books’ and you will see there are already almost 300 000 books written on EBM. This is extraordinary growth, given the term ‘evidencebased medicine’ appeared for the first time in the medical literature in 1991.1 Gordon Guyatt (McMaster University, Canada) is credited with first use of the term, initially in a short abstract,1 and the following year, when chairing the EvidenceBased Medicine Working Group, when he suggested EBM as a ‘new approach to teaching the practice of medicine’.2 Consequently, you may predict the history of EBM spans only 23 years – but this is clearly not the case.
History of EBM A great deal has already been written about the history of EBM, including a very recent oral history, published jointly by the BMJ and JAMA in January 2014.3 Those with a particular interest in EBM should view the excellent video of a number of EBM champions being interviewed by the previous editor of the BMJ, Richard Smith (http://ebm.jamanetwork .com).
Correspondence: Professor Craig Mellis, Central Clinical School, University of Sydney, Blackburn Building D06, Sydney, NSW 2006, Australia. Fax: +61-2-9036-5474; email: [email protected] Conflict of interest: None declared. Accepted for publication 15 May 2014.
While the term ‘EBM’ is recent, common sense tells us that the practice of medicine has, for centuries, been informed by what was considered the best available evidence at that time. Indeed, historians trace EBM’s origins to the 1700s – the so-called ‘enlightenment period’, a period during which ‘authority and anecdotal evidence was challenged by skepticism and the demand for formal evidence’.4 A legendary example, published in 1753, is the controlled trial of oranges and lemons for the prevention of scurvy by James Lind, Scottish naval surgeon.5
What Was the Role of ‘Clinical Epidemiology’? Modern-day EBM was preceded last century by the discipline of ‘clinical epidemiology’, and several key figures are recognised as the early champions of utilising published clinical research evidence to optimise patient care. In particular, we have the late Archie Cochrane, whose name was immortalised in the ‘Cochrane Library’, which celebrated its 20th anniversary in 2013;6 the late Alvan Feinstein who introduced the term ‘clinimetrics’ in the 1980s when he developed quantitative methods to measure and analyse clinical data;7,8 and Dave Sackett, whom many regard as the ‘father of EBM’, who established the first department of clinical epidemiology and biostatistics at McMaster University, Canada in the late 1960s.9
The Initial Focus on ‘Critical Appraisal’ In the late 1970s, Sackett developed the notion of ‘critical appraisal of the literature’, a methodology to assess the risk of
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
65
Evidence-based medicine
C Mellis
bias in published clinical research articles. Shortly after, in the early 1980s, Sackett edited a now famous series of articles on critical appraisal in the Canadian Medical Association Journal,10 the ‘Readers’ Guides’, which, in the early 1990s, was renamed the ‘Users’ Guides to the Medical Literature’.11
Adding ‘Patient’s Values and Preferences’ In the mid-1990s, a crucial advance in EBM was placing the patient at the centre of clinical decision-making.12 Integrating the ‘patient’s values and preferences’ and the patient’s ‘unique clinical context’ (such as co-morbidities, drug allergies or potential drug interactions) added a third pillar of EBM, as shown diagrammatically in Figure 1. This advance recognised that evidence alone cannot make clinical decisions, and partly overcame some of the earlier criticism of EBM as ‘recipe medicine’.13
PaƟent Factors Clinician Factors
Values and Preferences Co-morbidiƟes
CommunicaƟon Skills Clinical ExperƟse
Fig. 1
Evidence Strength and Quality of Evidence
The evidence-based medicine process.
UƟlisaƟon by Clinicians: Secondary research (pre-appraised)
Why Was EBM so Rapidly Adopted? There are a number of reasons why EBM was so rapidly adopted globally. First is the explicit and transparent nature of the EBM process (Fig. 1), including the refinement of critical appraisal checklists to reliably assess the risk of bias (validity) in published studies, the recognition of the key role of the patient’s preferences and the clinician’s expertise. Second is the widespread availability of searchable, electronic databases (particularly free websites, such as Medline via ‘PubMed’), thus enabling rapid acquisition of the relevant clinical research. Third is an appreciation of the ‘hierarchy’ of clinical research evidence and research study designs, particularly regarding therapy (Fig. 2).
The Clinician’s Expertise and EBM Clearly, evidence is simply one component of the complex process of clinical decision-making – the other key elements being the patient and the clinician.14 Considerable clinical expertise is fundamental to optimal clinical decision-making. This includes everything from accurate clinical assessment, diagnostic skills, the ability to find the best available evidence, the ability to communicate the risks and benefits of interventions, and the ability to clarify the patient’s values and preferences. Substantial clinical expertise is required to effectively integrate these three elements of clinical decision-making. Again, the clear recognition of the key role of the ‘clinicians’ expertise’ was essential to address the criticism of EBM – that the clinician was less important than the evidence (Fig. 1).
What Is ‘Traditional’ EBM? The process or steps involved in traditional EBM are summarised in Figure 3, and are as follows: 1 Assess the patient clinically and acknowledge any knowledge gaps.
Evidence-based guidelines (assessed via GRADE) Synopses (e.g. 'alert' systems) and synthesis of evidence (e.g. Up-to-Date, Best PracƟce)
al nic ne
l efu
Us
Randomised controlled trials (RCTs)
Cli
SystemaƟc reviews/meta-analyses (incl. Cochrane Reviews)
ss
For Clinical Researchers: Primary research (not appraised)
Cohort studies, case control studies Expert opinion, editorial, narraƟve reviews, laboratory studies
Fig. 2
66
Hierarchy of clinical research evidence and research study designs. GRADE, Grading of Recommendations Assessment, Development and Evaluation.
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
C Mellis
Evidence-based medicine
should take the form of a ‘treatment guideline’, which must be of high quality, thoroughly researched to ensure a strong evidence base and frequently updated – preferably using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to assess both the quality of the evidence and the strength of the recommendation.16 Such guidelines provide clinicians with easily accessible, reliable, up-to-date and concise information, essential for effective evidence-based practice.
Is It Possible to Keep Up to Date?
Fig. 3
Clinical application of traditional evidence-based medicine.
2 Ask your clinical question (i.e. address your knowledge gaps) by framing the question in the PICO format (i.e. population, intervention, comparator, outcome). 3 Acquire the evidence – using the appropriate database and an efficient computer search strategy, using your PICO question. 4 Appraise the evidence – employing the appropriate critical appraisal checklists (‘User’s Guides’) to assess the risk of bias (validity) and the importance of the results, that is, the magnitude (e.g. relative risk or odds ratio) and precision (i.e. the 95% confidence interval) of the effect size, plus the clinical relevance of the outcome measures. 5 Applicability of the research evidence to your patient, that is, how closely the clinical research question and the study population match your patient and your patient’s clinical question (i.e. ‘directness’ of the evidence). 6 Act. This assumes you have confidence in the evidence, that there is minimal risk of bias, the effect size of the intervention is clinically relevant (as well as statistically significant), the outcome measure is important to the patient (e.g. death, hospitalisation, quality of life), that you have evaluated both the risks as well as the benefits of the intervention and have clearly elicited the patient’s values and preferences regarding the treatment options (including the ‘no treatment’ option).
Evidence Summaries It has become clear that what clinicians really need to practice EBM are high-quality, easily accessible, brief evidence summaries, with clear recommendations regarding the respective risks and benefits of interventions.15 Busy clinicians do not have the time or the skills to carry out the above time- consuming steps in ‘traditional’ EBM, nor should they even try to find and appraise the primary clinical research literature. Instead, clinicians should always seek filtered, pre-appraised evidence. These evidence summaries can take the form of systematic reviews (with or without a meta-analysis), such as those in the Cochrane Library. Alternatives include evidence summaries in commercial, user-pay databases, such as ‘Up-to-Date’ (Wolters Kluwer) and ‘Best Practice’ (BMJ). The ideal evidence summary
To tackle the problem of the overwhelming volume of clinical research now published, there are many efficient and readily available ‘alert systems’. These automatically notify clinicians of new, relevant and important clinical research publications in their discipline. Many of these alert systems are free, and most can be tailored to the specific needs of the clinician. Examples include ‘Clinical Evidence’ (BMJ) and the New England Journal of Medicine’s free alert system. This method of notifying clinicians about relevant and important research (so-called ‘pushing’ evidence) offers clinicians a relatively simple means of keeping up-to-date with important advances in their discipline.17
The Gap between ‘Evidence and Practice’ A significant problem in EBM is the gap between the publication of high-quality clinical research evidence and the unfortunate delay in implementation of these findings by clinicians. A new discipline of EBM research has emerged to address the problem – known as knowledge transfer (KT) or implementation science.18 The purpose of KT is to supply continuing medical education to front line clinicians regarding important new clinical research evidence relevant to their practice, and to understand how to alter practice behaviour to hasten clinical uptake of proven interventions.
How to Avoid Being Misled A further EBM advance was the recognition that the clinical research literature can be misleading, and current checklists for critical appraisal may not detect these problems.19 These authors pointed out a number of ways of avoiding being misled: 1 Typically, the ‘spin’ by authors is in the Discussion, which is easily avoided by confining your reading of a clinical research paper to the ‘methods and results’ only. 2 Beware of surrogate outcome measures (non-patient important, e.g. laboratory measures, such as FEV1); beware of composite outcome measures (e.g. combining a laboratory measure with a patient important outcome, such as death); and beware of faulty comparators (e.g. dose and/or preparation); 3 Take great care when reading papers intending to demonstrate either ‘non-inferiority’ or ‘equivalence’. 4 Be highly suspicious of any trial ‘stopped early for benefit’. Subsequent trials frequently demonstrate that the ‘stopping’ was premature, resulting in a falsely large effect size.
Has EBM Been a Significant Advance? It is clear that clinicians consider EBM to be a highly significant advance. In 2007, over 11 000 readers of the BMJ voted for
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
67
Evidence-based medicine
C Mellis
what they considered the most important medical milestones since the first publication of the BMJ in 1840, and EBM was ranked in the top 15.20
EBM Limitations? Although modern-day EBM has been overwhelmingly successful, there remain limitations to effective evidence-based practice. For example, compared with adult medicine, paediatric practice suffers from a relative paucity of high-quality clinical research on both interventions and the evaluation of diagnostic tests..21 There are also many practical barriers to carrying out high-quality surgical research, especially performing randomised controlled trial with blinding. Nevertheless, evidence-based surgery is now thoroughly accepted, and many alternative, feasible study designs and methodological techniques have been developed to answer surgical questions.22
Where Is EBM Heading in the Future? EBM has recently moved to researching new and important issues from the patient’s perspective. Examples are research on shared decision-making and the development and evaluation of patient decision aids to ensure patients are fully informed regarding treatment options. EBM research is also closely aligned with the increasingly important issue of patient safety. Current EBM researchers are also investigating the growing problem of ‘treatment burden’, that is, patients with multiple chronic disease suffering as a consequence of increasingly complex management, invasive disease monitoring, multiple medications (‘polypharmacy’) and frequent visits to multiple sub-specialist physicians.23 Clinicians are becoming more and more dependent on computers, and with widespread use of e-health records, the future of EBM will involve rapid advances in ‘clinical (or computer) decision support systems’. That is, at the point of care, the relevant evidence-based summary (e.g. treatment guideline) will pop up on your screen (or handheld device), with intervention options, further investigation and appropriate disease monitoring. Indeed, there is already a user’s guide checklist for appraisal of a clinical decision support system.24
References 1 Guyatt GH. Evidence-based medicine. ACP J. Club 1991; 114: A–16. 2 Guyatt GH, Cairns J, Churchill D et al. Evidence-based medicine. JAMA 1992; 268: 2420–5. 3 Smith R, Rennie D. Evidence-based medicine – an oral history. JAMA 2014; 311: 365–7.
68
4 Trohler U. To improve the evidence of medicine: the 18th Century British origins of a critical approach. J. R. Soc. Med. 2001; 94: 204–5. 5 Isaacs D. Evidence-based medicine. J. Paediatr. Child Health 2014; 50: 579–80. 6 Starr M, Chalmers I, Clarke M. The origins, evolution, and future of the Cochrane Database of Systematic Reviews. Int. J. Technol. Assess. Health Care 2009; 25: 182–95. 7 Feinstein AR. An additional basic science for clinical medicine: IV. The development of clinimetrics. Ann. Intern. Med. 1983; 99: 843–8. 8 Fava GA, Tomba E, Sonino N. Clinimetrics: the science of clinical measurements. Int. J. Clin. Pract. 2012; 66: 11–15. 9 Zimerman AL. Evidence-based medicine: a short history of a modern medical movement. Virtual Mentor 2013; 15: 71–6. 10 Department of Clinical Epidemiology and Biostatistics, McMaster University. How to read clinical journals: I. Why to read them and how to start reading them critically. Can. Med. Assoc. J. 1981; 124: 555–8. 11 Guyatt GH, Rennie D. Users’ guides to the medical literature. JAMA 1993; 270: 2096–7. 12 Sackett DL, Rosenberg WMC, Muir Gray JA et al. Evidence-based medicine: what it is and what it isn’t. BMJ 1996; 312: 71–80. 13 Straus SE, McAlister FA. Evidence-based medicine: a commentary on common criticisms. CMAJ 2000; 163: 837–41. 14 Hayens RB, Devereaux PJ, Guyatt GH. Clinical expertise in the era of evidence-based medicine and patient choice. Evid. Based Med. 2002; 7: 36–8. 15 Hayens RB. Of studies, syntheses, synopses, summaries, and systems: the ‘5S’ evolution of information services for evidence-based healthcare decisions. Evid. Based Med. 2006; 11: 162–4. 16 Guyatt GH, Oxman AD, Vist G et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ 2008; 336: 924–6. 17 Glaziou PP, Del Mar C, Salisbury J. Evidence-Based Practice Workbook: Finding and Applying the Best Research Evidence to Improve Patient Care. London: BMJ Publishing Group, 2003; 13. 18 Lang ES, Wyer PC, Hayens RB. Knowledge translation: closing the evidence-to-practice gap. Ann. Emerg. Med. 2007; 49: 355–63. 19 Montori VM, Jaeschke R, Schunemann HJ et al. Users’ guide to detecting misleading claims in clinical research reports. BMJ 2004; 329: 1093–6. 20 Godlee F. Milestones on the long road to knowledge. BMJ 2007; 334: 127–9. 21 Gazarian M. Delivering better medicines to children: need for better integration between the science, the policy, and the practice. Paediatr. Drugs 2009; 11: 41–4. 22 Merkow RP, Ko CY. Evidence-based medicine in surgery: the importance of both experimental and observational study designs. JAMA 2011; 306: 436–7. 23 May C, Montori V, Mair F. We need minimally disruptive medicine. BMJ 2009; 339: 485–7. 24 Guyatt GH, Rennie D, O’Meade M et al. JAMA Users’ Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice, 2nd edn. New York, USA: McGraw Hill, 2008; 193–208.
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
doi:10.1111/jpc.12800
REVIEW ARTICLE
Evidence-based medicine: What has happened in the past 50 years? Craig Mellis Central Clinical School, University of Sydney, Sydney, New South Wales, Australia
Abstract: Although the phrase ‘evidence-based medicine’ (EBM) was used for the first time in the medical literature less than 25 years ago, the history of EBM goes back for centuries. What is remarkable is how popular and how globally accepted the EBM movement has become in such a short time. Many famous, past clinicians have played major roles in the disciplines that preceded EBM, particularly ‘clinical epidemiology’. It soon became clear to the early EBM champions that ‘evidence’ was only part of the clinical decision-making process. Consequently, both clinical expertise and the patient’s values and preferences were rapidly incorporated into the concept we now know as ‘EBM’. The current need for high-quality, easily accessible ‘evidence-based summaries’ for busy clinicians is now apparent, as traditional EBM requires both considerable time and skill. Consequently, there is a progressive move away from the primary literature (such as randomised controlled trials) to systematic reviews and other ‘evidence-based summaries’. The future of EBM will almost certainly involve widespread utilisation of ‘clinical (computer)based decision support systems’. Key words:
clinical epidemiology; evidence based medicine; general paediatrics; history.
Introduction Enter the phrase ‘evidence-based medicine’ (EBM) into ‘Google’ and you will get over 60 million results; try ‘EBM books’ and you will see there are already almost 300 000 books written on EBM. This is extraordinary growth, given the term ‘evidencebased medicine’ appeared for the first time in the medical literature in 1991.1 Gordon Guyatt (McMaster University, Canada) is credited with first use of the term, initially in a short abstract,1 and the following year, when chairing the EvidenceBased Medicine Working Group, when he suggested EBM as a ‘new approach to teaching the practice of medicine’.2 Consequently, you may predict the history of EBM spans only 23 years – but this is clearly not the case.
History of EBM A great deal has already been written about the history of EBM, including a very recent oral history, published jointly by the BMJ and JAMA in January 2014.3 Those with a particular interest in EBM should view the excellent video of a number of EBM champions being interviewed by the previous editor of the BMJ, Richard Smith (http://ebm.jamanetwork .com).
Correspondence: Professor Craig Mellis, Central Clinical School, University of Sydney, Blackburn Building D06, Sydney, NSW 2006, Australia. Fax: +61-2-9036-5474; email: [email protected] Conflict of interest: None declared. Accepted for publication 15 May 2014.
While the term ‘EBM’ is recent, common sense tells us that the practice of medicine has, for centuries, been informed by what was considered the best available evidence at that time. Indeed, historians trace EBM’s origins to the 1700s – the so-called ‘enlightenment period’, a period during which ‘authority and anecdotal evidence was challenged by skepticism and the demand for formal evidence’.4 A legendary example, published in 1753, is the controlled trial of oranges and lemons for the prevention of scurvy by James Lind, Scottish naval surgeon.5
What Was the Role of ‘Clinical Epidemiology’? Modern-day EBM was preceded last century by the discipline of ‘clinical epidemiology’, and several key figures are recognised as the early champions of utilising published clinical research evidence to optimise patient care. In particular, we have the late Archie Cochrane, whose name was immortalised in the ‘Cochrane Library’, which celebrated its 20th anniversary in 2013;6 the late Alvan Feinstein who introduced the term ‘clinimetrics’ in the 1980s when he developed quantitative methods to measure and analyse clinical data;7,8 and Dave Sackett, whom many regard as the ‘father of EBM’, who established the first department of clinical epidemiology and biostatistics at McMaster University, Canada in the late 1960s.9
The Initial Focus on ‘Critical Appraisal’ In the late 1970s, Sackett developed the notion of ‘critical appraisal of the literature’, a methodology to assess the risk of
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
65
Evidence-based medicine
C Mellis
bias in published clinical research articles. Shortly after, in the early 1980s, Sackett edited a now famous series of articles on critical appraisal in the Canadian Medical Association Journal,10 the ‘Readers’ Guides’, which, in the early 1990s, was renamed the ‘Users’ Guides to the Medical Literature’.11
Adding ‘Patient’s Values and Preferences’ In the mid-1990s, a crucial advance in EBM was placing the patient at the centre of clinical decision-making.12 Integrating the ‘patient’s values and preferences’ and the patient’s ‘unique clinical context’ (such as co-morbidities, drug allergies or potential drug interactions) added a third pillar of EBM, as shown diagrammatically in Figure 1. This advance recognised that evidence alone cannot make clinical decisions, and partly overcame some of the earlier criticism of EBM as ‘recipe medicine’.13
PaƟent Factors Clinician Factors
Values and Preferences Co-morbidiƟes
CommunicaƟon Skills Clinical ExperƟse
Fig. 1
Evidence Strength and Quality of Evidence
The evidence-based medicine process.
UƟlisaƟon by Clinicians: Secondary research (pre-appraised)
Why Was EBM so Rapidly Adopted? There are a number of reasons why EBM was so rapidly adopted globally. First is the explicit and transparent nature of the EBM process (Fig. 1), including the refinement of critical appraisal checklists to reliably assess the risk of bias (validity) in published studies, the recognition of the key role of the patient’s preferences and the clinician’s expertise. Second is the widespread availability of searchable, electronic databases (particularly free websites, such as Medline via ‘PubMed’), thus enabling rapid acquisition of the relevant clinical research. Third is an appreciation of the ‘hierarchy’ of clinical research evidence and research study designs, particularly regarding therapy (Fig. 2).
The Clinician’s Expertise and EBM Clearly, evidence is simply one component of the complex process of clinical decision-making – the other key elements being the patient and the clinician.14 Considerable clinical expertise is fundamental to optimal clinical decision-making. This includes everything from accurate clinical assessment, diagnostic skills, the ability to find the best available evidence, the ability to communicate the risks and benefits of interventions, and the ability to clarify the patient’s values and preferences. Substantial clinical expertise is required to effectively integrate these three elements of clinical decision-making. Again, the clear recognition of the key role of the ‘clinicians’ expertise’ was essential to address the criticism of EBM – that the clinician was less important than the evidence (Fig. 1).
What Is ‘Traditional’ EBM? The process or steps involved in traditional EBM are summarised in Figure 3, and are as follows: 1 Assess the patient clinically and acknowledge any knowledge gaps.
Evidence-based guidelines (assessed via GRADE) Synopses (e.g. 'alert' systems) and synthesis of evidence (e.g. Up-to-Date, Best PracƟce)
al nic ne
l efu
Us
Randomised controlled trials (RCTs)
Cli
SystemaƟc reviews/meta-analyses (incl. Cochrane Reviews)
ss
For Clinical Researchers: Primary research (not appraised)
Cohort studies, case control studies Expert opinion, editorial, narraƟve reviews, laboratory studies
Fig. 2
66
Hierarchy of clinical research evidence and research study designs. GRADE, Grading of Recommendations Assessment, Development and Evaluation.
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
C Mellis
Evidence-based medicine
should take the form of a ‘treatment guideline’, which must be of high quality, thoroughly researched to ensure a strong evidence base and frequently updated – preferably using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to assess both the quality of the evidence and the strength of the recommendation.16 Such guidelines provide clinicians with easily accessible, reliable, up-to-date and concise information, essential for effective evidence-based practice.
Is It Possible to Keep Up to Date?
Fig. 3
Clinical application of traditional evidence-based medicine.
2 Ask your clinical question (i.e. address your knowledge gaps) by framing the question in the PICO format (i.e. population, intervention, comparator, outcome). 3 Acquire the evidence – using the appropriate database and an efficient computer search strategy, using your PICO question. 4 Appraise the evidence – employing the appropriate critical appraisal checklists (‘User’s Guides’) to assess the risk of bias (validity) and the importance of the results, that is, the magnitude (e.g. relative risk or odds ratio) and precision (i.e. the 95% confidence interval) of the effect size, plus the clinical relevance of the outcome measures. 5 Applicability of the research evidence to your patient, that is, how closely the clinical research question and the study population match your patient and your patient’s clinical question (i.e. ‘directness’ of the evidence). 6 Act. This assumes you have confidence in the evidence, that there is minimal risk of bias, the effect size of the intervention is clinically relevant (as well as statistically significant), the outcome measure is important to the patient (e.g. death, hospitalisation, quality of life), that you have evaluated both the risks as well as the benefits of the intervention and have clearly elicited the patient’s values and preferences regarding the treatment options (including the ‘no treatment’ option).
Evidence Summaries It has become clear that what clinicians really need to practice EBM are high-quality, easily accessible, brief evidence summaries, with clear recommendations regarding the respective risks and benefits of interventions.15 Busy clinicians do not have the time or the skills to carry out the above time- consuming steps in ‘traditional’ EBM, nor should they even try to find and appraise the primary clinical research literature. Instead, clinicians should always seek filtered, pre-appraised evidence. These evidence summaries can take the form of systematic reviews (with or without a meta-analysis), such as those in the Cochrane Library. Alternatives include evidence summaries in commercial, user-pay databases, such as ‘Up-to-Date’ (Wolters Kluwer) and ‘Best Practice’ (BMJ). The ideal evidence summary
To tackle the problem of the overwhelming volume of clinical research now published, there are many efficient and readily available ‘alert systems’. These automatically notify clinicians of new, relevant and important clinical research publications in their discipline. Many of these alert systems are free, and most can be tailored to the specific needs of the clinician. Examples include ‘Clinical Evidence’ (BMJ) and the New England Journal of Medicine’s free alert system. This method of notifying clinicians about relevant and important research (so-called ‘pushing’ evidence) offers clinicians a relatively simple means of keeping up-to-date with important advances in their discipline.17
The Gap between ‘Evidence and Practice’ A significant problem in EBM is the gap between the publication of high-quality clinical research evidence and the unfortunate delay in implementation of these findings by clinicians. A new discipline of EBM research has emerged to address the problem – known as knowledge transfer (KT) or implementation science.18 The purpose of KT is to supply continuing medical education to front line clinicians regarding important new clinical research evidence relevant to their practice, and to understand how to alter practice behaviour to hasten clinical uptake of proven interventions.
How to Avoid Being Misled A further EBM advance was the recognition that the clinical research literature can be misleading, and current checklists for critical appraisal may not detect these problems.19 These authors pointed out a number of ways of avoiding being misled: 1 Typically, the ‘spin’ by authors is in the Discussion, which is easily avoided by confining your reading of a clinical research paper to the ‘methods and results’ only. 2 Beware of surrogate outcome measures (non-patient important, e.g. laboratory measures, such as FEV1); beware of composite outcome measures (e.g. combining a laboratory measure with a patient important outcome, such as death); and beware of faulty comparators (e.g. dose and/or preparation); 3 Take great care when reading papers intending to demonstrate either ‘non-inferiority’ or ‘equivalence’. 4 Be highly suspicious of any trial ‘stopped early for benefit’. Subsequent trials frequently demonstrate that the ‘stopping’ was premature, resulting in a falsely large effect size.
Has EBM Been a Significant Advance? It is clear that clinicians consider EBM to be a highly significant advance. In 2007, over 11 000 readers of the BMJ voted for
Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
67
Evidence-based medicine
C Mellis
what they considered the most important medical milestones since the first publication of the BMJ in 1840, and EBM was ranked in the top 15.20
EBM Limitations? Although modern-day EBM has been overwhelmingly successful, there remain limitations to effective evidence-based practice. For example, compared with adult medicine, paediatric practice suffers from a relative paucity of high-quality clinical research on both interventions and the evaluation of diagnostic tests..21 There are also many practical barriers to carrying out high-quality surgical research, especially performing randomised controlled trial with blinding. Nevertheless, evidence-based surgery is now thoroughly accepted, and many alternative, feasible study designs and methodological techniques have been developed to answer surgical questions.22
Where Is EBM Heading in the Future? EBM has recently moved to researching new and important issues from the patient’s perspective. Examples are research on shared decision-making and the development and evaluation of patient decision aids to ensure patients are fully informed regarding treatment options. EBM research is also closely aligned with the increasingly important issue of patient safety. Current EBM researchers are also investigating the growing problem of ‘treatment burden’, that is, patients with multiple chronic disease suffering as a consequence of increasingly complex management, invasive disease monitoring, multiple medications (‘polypharmacy’) and frequent visits to multiple sub-specialist physicians.23 Clinicians are becoming more and more dependent on computers, and with widespread use of e-health records, the future of EBM will involve rapid advances in ‘clinical (or computer) decision support systems’. That is, at the point of care, the relevant evidence-based summary (e.g. treatment guideline) will pop up on your screen (or handheld device), with intervention options, further investigation and appropriate disease monitoring. Indeed, there is already a user’s guide checklist for appraisal of a clinical decision support system.24
References 1 Guyatt GH. Evidence-based medicine. ACP J. Club 1991; 114: A–16. 2 Guyatt GH, Cairns J, Churchill D et al. Evidence-based medicine. JAMA 1992; 268: 2420–5. 3 Smith R, Rennie D. Evidence-based medicine – an oral history. JAMA 2014; 311: 365–7.
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Journal of Paediatrics and Child Health 51 (2015) 65–68 © 2014 The Author Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians)
