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Evidence-based medicine—An old friend or a new foe?
Asia Pacific
Heart J 1998;7(2)
Evidence-based
Guest Editorial Medicine - An Old Friend Or A New Foe? into medical practice in both urban and rural areas. Despite this, some doubts about evidence-based medicine remain. The quality of the evidence is clearly important, and recent doubts have appropriately been raised about the accuracy of meta-analyses.4 Even the high level evidence of randomised controlled trials may be inapplicable in some situations, as it is rare for all eligible patients, or even the majority, to be enrolled into clinical trial design. For example, in the large number of randomised trials comparing medical outcomes of coronary balloon angioplasty with bypass surgery, less than 10% of all eligible patients were actually randomised.5 This obviously raises concerns about the applicability of published results in trials of this nature. Finally, there is the suspicion that the agenda in randomised controlled trials can be driven by industry, as these trials are expensive to perform and much more likely to be conducted with the support of a pharmaceutical sponsor.
ith almost lightning speed, the reality of evidencebased medicine is upon us. Almost like a new religion, its doctrines are chanted like mantras by its new “high priests”, usually academic epidemiologists and health economists rather than practising clinicians. The definition of what constitutes evidence-based medicine is variable. Many believe it to be an “old friend”, well known to clinicians over many years of practice. In this guise, evidence-based medicine is the use of the best available published evidence, considered carefully in the context of an individual patient, whose particular situation may vary considerably from that of the subjects studied in the published literature. In this iteration, published evidence is balanced in the clinician’s mind against individual patient considerations and a degree of clinical intuition. Unfortunately, there are some harsher definitions of evidence-based medicine, where it becomes a “new foe” with which clinicians feel distinctly uncomfortable. In the minds of some, evidence-based medicine is the practice of clinical medicine which is driven almost exclusively by published results of “proven” therapies; that is, therapies and decisions can only be invoked if supported by high levels of published evidence.
In this issue of the Journal, Richard Smallwood explores many of these realities of evidence-based medicine.6 He has used the definition that we would all wish for, where optimal care is based on the best available evidence allied with each doctor’s clinical expertise and judgement. It is important that the clinical and academic medical communities have open debate about the definition and adoption of evidence-based medicine, as this will allow clinicians to drive the medical agenda, rather than have it determined by economic rationalists and healthcare bureaucrats.
The concept of having their day-to-day practice being driven by published evidence only has resulted in understandable reluctance by many clinicians. The amount of literature published is daunting and difficult for even the most motivated practitioners to assimilate. Furthermore there are “grey zones”, where the evidence is unclear or even internally inconsistent.
David S. Celermajer Department of Cardiology Royal Prince Alfred Hospital Sydney, N.S.W., Australia
Clinicians are also innately wary of “practice guidelines”, based on “best available evidence”, which may constrain their ability to vary guidelines in the cases of individual patients, and may even pose a medico-legal threat in some circumstances. Finally, some are skeptical that the real agenda of evidence-based medicine might be to facilitate cost cutting of promising but unproven therapies and technologies.
References 1
2.
There is no doubt that evidence from clinical trials is tremendously important in driving clinical practice. Positive findings from randomised controlled trials in the areas of thrombolysis and cholesterol lowering, for example, have provided important breakthroughs in preventing cardiovascular morbidity and mortality.i.2 Furthermore, important negative findings, such as the potential dangers of certain anti-arrhythmic agents after myocardial infarction, heralded by the CAST study, have also provided valuable information for clinicians.3 By and large, these results have been assimilated quickly
3.
4.
5.
6.
89
The GUSTO investigators. An international randomized trial comparing four thrombolytic strategies for acute myocardial infarction. N Engl J Med 1993;329:673-82. Scandinavian Simvastatin Survival Study group. Randomised trial of cholesterol lowering in 4,444 patients with coronary heart disease. Lancet 1994,314: 1383-9. Preliminary report: effect of encainide and flecainide on mortality in a randomized trial of arrhythmia suppression after myocardial infarction (CAST). N Engl J Med 1989;321:406-12. Lelorier J, Gregoire G, Benhaddad A, Lapierre J, Derderiad F. Discrepancies between meta-analyses and subsequent large, randomized controlled trials. N Engl J Med 1997;337:536-42 Pocock ST, Henderson RA, Rickards AF, et al. Meta-analysis of randomised trials comparing coronary angioplasty with bypass surgery. Lancet 199.5;346:1184-9. Smallwood RA. The realities of evidence-based medicine. Asia Pacific Heart J 1998;7(2):121-4.
Heart J 1998;7(2)
Evidence-based
Guest Editorial Medicine - An Old Friend Or A New Foe? into medical practice in both urban and rural areas. Despite this, some doubts about evidence-based medicine remain. The quality of the evidence is clearly important, and recent doubts have appropriately been raised about the accuracy of meta-analyses.4 Even the high level evidence of randomised controlled trials may be inapplicable in some situations, as it is rare for all eligible patients, or even the majority, to be enrolled into clinical trial design. For example, in the large number of randomised trials comparing medical outcomes of coronary balloon angioplasty with bypass surgery, less than 10% of all eligible patients were actually randomised.5 This obviously raises concerns about the applicability of published results in trials of this nature. Finally, there is the suspicion that the agenda in randomised controlled trials can be driven by industry, as these trials are expensive to perform and much more likely to be conducted with the support of a pharmaceutical sponsor.
ith almost lightning speed, the reality of evidencebased medicine is upon us. Almost like a new religion, its doctrines are chanted like mantras by its new “high priests”, usually academic epidemiologists and health economists rather than practising clinicians. The definition of what constitutes evidence-based medicine is variable. Many believe it to be an “old friend”, well known to clinicians over many years of practice. In this guise, evidence-based medicine is the use of the best available published evidence, considered carefully in the context of an individual patient, whose particular situation may vary considerably from that of the subjects studied in the published literature. In this iteration, published evidence is balanced in the clinician’s mind against individual patient considerations and a degree of clinical intuition. Unfortunately, there are some harsher definitions of evidence-based medicine, where it becomes a “new foe” with which clinicians feel distinctly uncomfortable. In the minds of some, evidence-based medicine is the practice of clinical medicine which is driven almost exclusively by published results of “proven” therapies; that is, therapies and decisions can only be invoked if supported by high levels of published evidence.
In this issue of the Journal, Richard Smallwood explores many of these realities of evidence-based medicine.6 He has used the definition that we would all wish for, where optimal care is based on the best available evidence allied with each doctor’s clinical expertise and judgement. It is important that the clinical and academic medical communities have open debate about the definition and adoption of evidence-based medicine, as this will allow clinicians to drive the medical agenda, rather than have it determined by economic rationalists and healthcare bureaucrats.
The concept of having their day-to-day practice being driven by published evidence only has resulted in understandable reluctance by many clinicians. The amount of literature published is daunting and difficult for even the most motivated practitioners to assimilate. Furthermore there are “grey zones”, where the evidence is unclear or even internally inconsistent.
David S. Celermajer Department of Cardiology Royal Prince Alfred Hospital Sydney, N.S.W., Australia
Clinicians are also innately wary of “practice guidelines”, based on “best available evidence”, which may constrain their ability to vary guidelines in the cases of individual patients, and may even pose a medico-legal threat in some circumstances. Finally, some are skeptical that the real agenda of evidence-based medicine might be to facilitate cost cutting of promising but unproven therapies and technologies.
References 1
2.
There is no doubt that evidence from clinical trials is tremendously important in driving clinical practice. Positive findings from randomised controlled trials in the areas of thrombolysis and cholesterol lowering, for example, have provided important breakthroughs in preventing cardiovascular morbidity and mortality.i.2 Furthermore, important negative findings, such as the potential dangers of certain anti-arrhythmic agents after myocardial infarction, heralded by the CAST study, have also provided valuable information for clinicians.3 By and large, these results have been assimilated quickly
3.
4.
5.
6.
89
The GUSTO investigators. An international randomized trial comparing four thrombolytic strategies for acute myocardial infarction. N Engl J Med 1993;329:673-82. Scandinavian Simvastatin Survival Study group. Randomised trial of cholesterol lowering in 4,444 patients with coronary heart disease. Lancet 1994,314: 1383-9. Preliminary report: effect of encainide and flecainide on mortality in a randomized trial of arrhythmia suppression after myocardial infarction (CAST). N Engl J Med 1989;321:406-12. Lelorier J, Gregoire G, Benhaddad A, Lapierre J, Derderiad F. Discrepancies between meta-analyses and subsequent large, randomized controlled trials. N Engl J Med 1997;337:536-42 Pocock ST, Henderson RA, Rickards AF, et al. Meta-analysis of randomised trials comparing coronary angioplasty with bypass surgery. Lancet 199.5;346:1184-9. Smallwood RA. The realities of evidence-based medicine. Asia Pacific Heart J 1998;7(2):121-4.