What colour is a polar bear? ‘That’s a dumb question,” you think. ‘Everyone knows polar bears are white.” Actually the correct answer is ‘black”. The reason why polar bears look white is because of the way their transparent fur reflects visible light. Their skin underneath the fur is, in fact, black.
Finding out that ‘what we know isn’t so” is a humbling and, at times, distressing experience. But for those who embrace it the experience can be empowering and liberating, with benefits for society at large.
The proper role for institutions of higher learning is to facilitate discovery by encouraging curiosity and critical thinking. Students must learn the importance of holding up their beliefs and suppositions to the light of dawning knowledge. False certainties ultimately benefit no one and might harm many. In the health professions, where the potential to do harm is huge, the implications of wrong-headed ideas can be particularly dire.
Take, for instance, leeching — the 19th century remedy for infections. In vogue for more than 100 years, the practice was based on the theory that redness, heat and swelling — seen in cases of inflammation — is due to an excess of blood. It seemed logical that the removal of blood would lessen the pressure and cure the inflammation. Leeching and other forms of bloodletting received wide support within the medical fraternity at the time, including from Sir William Osler, ‘the most influential physician in history”.
Yet today we know that the treatment probably killed hundreds of thousands of people.
Such medical disasters are by no means limited to the pre-scientific era. A recent example is the routine use of drugs to suppress abnormal heart rhythms in people suffering a heart attack. A rationale for this treatment was based on the observation that irregular heartbeats are common in the early period following a heart attack, making patients particularly vulnerable to cardiac arrest and death.
It had been demonstrated in animals and humans that abnormal beats could be suppressed by anti-arrhythmic drugs. On the strength of these observations the drugs were adopted into clinical practice.
Several years later, when clinical trials were eventually conducted, they confirmed the benefit of anti-arrhythmic drugs for controlling abnormal heartbeats but, to everyone’s surprise and dismay, a higher mortality rate was found in people receiving these drugs compared with those on placebo (dummy tablets).
At the time the study findings became available it was estimated that routine anti-arrhythmic drugs had been responsible for between 20 000 and 70 000 deaths during the late 1980s in the United States alone — similar to the total number of Americans who died in the Vietnam war.
Health professionals are, in general, well-meaning individuals, guided by high ethical standards and dedicated to doing the best they can for the patients under their care. However, as these case studies illustrate, even with the best intentions in the world, they sometimes end up doing more harm than good.
It must be remembered that healthcare practitioners are human, so genuine mistakes are sometimes made, especially in emergency or otherwise challenging environments in which they typically function. Also, the limitations of drugs and other therapies are such that they cannot always be deployed with sufficient precision, making a certain amount of ‘collateral damage” inevitable.
However, perhaps the most crucial factor responsible for harm to patients is overconfidence on the part of clinicians in the therapeutic armamentarium at their disposal. How are universities addressing this issue?
Health sciences education in South Africa is, in the main, rooted in a paradigm that assumes traditional training and clinical experience, studying and understanding the basic mechanisms of disease and the advice of ‘experts” are sufficient guides to sound clinical practice.
Clinical experience is certainly crucial for becoming a competent practitioner, but anecdotal evidence derived from personal experience can be dangerously misleading.
Second, better understanding of the functioning of the human body at the molecular or tissue level has undoubtedly contributed much to the advancement of modern medicine. But history shows that treatments based on contemporary biological concepts and theories can cause serious harm.
Finally, expert opinion can be biased, tends to vary widely and is not always a reliable source of knowledge.
In most high- and middle-income countries medical schools and faculties of health sciences have responded to the limitations of these traditional sources of clinical knowledge by introducing evidence-based medicine (EBM). Defined as ‘the conscientious, explicit and judicious use of the current best evidence in making clinical decisions”, EBM seeks to integrate individual clinical expertise with reliable evidence from clinical practice research.
Students are taught how to formulate questions about disease causation, prognosis, diagnostic tests and treatment strategies. They also become conversant with search methods for relevant literature and criteria to appraise literature for validity and relevance, using established rules of evidence. Further, students receive instruction on how to apply evidence in solving clinical problems and on how to evaluate their own practice.
Internationally, feedback on this new approach to learning has been overwhelmingly positive. Students feel empowered through the acquisition of skills needed for making independent assessments of evidence, for confirming the veracity of their own clinical observations and for validating the opinions of experts. They also report having fun learning and finding it easier to keep up to date with new developments in healthcare.
Giving these clear benefits to current and future healthcare professionals — and by extension their patients — why does EBM teaching still remain marginalised in South African institutions? Why are there are so few EBM champions and why do only a handful of South African universities incorporate EBM into their undergraduate and postgraduate curricula?
One might speculate about the role of paternalism in South African society, authoritarianism in our healthcare professions or the challenges of persuading education programme committees to include new material in their already overfull curricula. Whatever the reasons, these must be addressed with the urgency they deserve to bring South African health sciences education in line with educational trends in the rest of the world.
Professor Jimmy Volmink is deputy dean (research) at the faculty of health sciences, Stellenbosch University, and co-director of the South African Cochrane Centre, Medical Research Council