In this article, we attempt to address the opinions expressed in The Hindu on the problems with Evidence Based Medicine (EBM).
EBM is not a new mantra. The term, coined nearly two decades ago, is in itself a myth that should be laid gracefully to rest, and replaced with ‘Evidence-Informed Healthcare.’
Dave Sackett’s definition of EBM as the “conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients” seems to have spawned misunderstandings about the role of evidence. The first is the interpretation that evidence was primary and other considerations were to be subservient. It is naïve to believe that the practice of medicine can be based entirely on evidence. There are many conditions for which there is little or no evidence of the effectiveness or safety of interventions; and others where the evidence is unreliable, or is simply not applicable, affordable, or practical to implement.
Another, related, misconception is that the evidence itself is the decision. The truth is that the evidence, or the lack of it, can only inform healthcare decisions. Decisions about whether to use, or not use an intervention, have to be contextualised for, and by, local realities.
Evidence-Informed Healthcare refers to the process of integrating the experience and expertise of the individual clinician, with the best available evidence from research, while incorporating the preferences, rights and individual circumstances of patients in making clinical decisions about their care. The linchpin of this envisaged therapeutic alliance is the astute clinician who can locate and understand what constitutes reliable, and clinically important (not just statistically significant), evidence. Evidence-informed Healthcare is a two-stage process: finding the right evidence; and using it in the contexts and circumstances of people’s lives.
Finding evidence that you can trust
It is true that a lot of research evidence is conflicted; sometimes fraudulent; often biased in their choice of comparators, outcomes, and the selective reporting of manipulated results; and even irrelevant to real-world decision-making.
However, it is through empirical research, central to the methods of the EBM movement, that these problems were identified in the first instance. The methods used in Cochrane systematic reviews are ideally suited to detect biased, conflicted, and even fraudulent research. Cochrane systematic reviews increasingly summarise their findings in tables that are linked to grades of the overall quality of the evidence, ranging from high to very low quality. These grades reveal the certainty or uncertainty that the results of the trials were unbiased, consistent, applicable, clinically important, un-conflicted, and likely to reflect the expected results when used in clinical practice; and also the likelihood that further research will alter these estimates.
Reliable evidence can save lives
Numerous examples exist where systematic reviews of well-conducted, randomised controlled trials (RCTs) have challenged established beliefs, helped optimise care and resource utilisation, prevented harm, and saved lives. For example, Cochrane systematic reviews have demonstrated the harms of long-term hormone therapy in peri-menopausal and post-menopausal women; the dubious efficacy and concerns of safety of human albumin solution for patients with shock; and the superior effects of magnesium sulphate over anticonvulsants in treating eclampsia (which results in seizures in pregnant women).
Reliable evidence has reduced unnecessary surgeries: such as routine tonsillectomies, disc excisions, surgeries for intra-cerebral haematoma, and for minor grades of carotid stenosis. Legislation regarding the use of helmets by motor cyclists, anti-smoking regulations, provision of mid-day meals in schools, adequate street lighting to reduce road traffic accidents and preventive interventions against common diseases were informed by robust evidence from systematic reviews of certain types of observational studies.
Clinicians who passively imbibe thinly-disguised attempts at marketing, at conferences or continuing medical education sessions sponsored by the pharmaceutical industry, do so to the detriment of health-outcomes in their patients.
The national subscription purchased for everyone in India to the full contents of The Cochrane Library (www.thecochranelibrary.com) by the Indian Council of Medical Research is an outstanding example of responsible leadership in healthcare and growing realisation by policymakers of the importance of reliable evidence to inform (not dictate) health decision-making.
Research evidence needs to be contextualised by the pragmatic realities, constraints and priorities of local public health needs in order to inform health policy. For example, the World Health Organisation strongly recommends the use of intravenous artesunate in preference to quinine in treating severe malaria due to P. falciparum in children; a recommendation backed by high quality evidence from a Cochrane systematic review of RCTs that showed artesunate resulted in appreciably fewer deaths than quinine in 5,764 children. However, some local governments in Africa have decided to continue with quinine since global research evidence and local data also demonstrated its efficacy in preventing deaths in children, and because the drug is cheaper and easily available, while artesunate is not. This is an example of evidence being used transparently to inform national health policies, not national policies being controlled by the evidence.
Particularising the evidence from research to a particular patient regarding the effectiveness (does it work in practice?) and efficiency (is it worth it?) of interventions are point of care decisions. These need good clinical acumen; knowledge of the patient’s individual circumstances; and the skills to correctly interpret, and communicate, the results of un-conflicted clinical research.
The enduring evidence-footprint of organisations like the Cochrane Collaboration (www.cochrane.org) has been in: a) generating evidence of the people, by the people, and for the people, and highlighting many areas where high quality evidence exists; b) identifying the many gaps in our evidence-base that require further primary research; and c) developing the methods to make this differentiation reliably.
This effort requires global partnerships and a collaborative approach that acknowledges that the evidence will continually change; and that uncertainty will always exist; but that does not let these become excuses for inaction; or for the unfettered exercise of personal opinion. The validity of the methods used will, in the final analysis, have to be judged also by those whose health outcomes are to be improved, not only by proponents, or sceptics of the Evidence-Informed Healthcare movement.
Sridharan Ramaratnam, Consultant Neurologist, Apollo Hospitals, Chennai; Editor, Cochrane Epilepsy Group (email: firstname.lastname@example.org).
Thambu David Sudarsanam, Professor of Medicine, Christian Medical College, Vellore; Editor, Cochrane Infectious Diseases Group (email: email@example.com).
Prathap Tharyan, Professor of Psychiatry and Director, South Asian Cochrane Centre, Prof BV Moses and ICMR Centre for Evidence-Informed Healthcare, Christian Medical College, Vellore; Editor Cochrane Schizophrenia Group (email: firstname.lastname@example.org).