Dr Aseem Malhotra is a renowned cardiologist, working in the NHS and leading the campaign against excess sugar consumption in the UK. He speaks regularly at national and international events on matters of heart disease, obesity and diabetes. As a strong believer in evidence-based medicine, he urges the healthcare community to be more open and knowledgeable about scientific data. This talk was given at the Public Health Collaboration conference 2017 in Manchester.
Ideally, evidence-based medicine should be practised whilst incorporating individual expertise and patient values. However, Dr Malhotra feels honest doctors can no longer practise honest medicine because of all the obstacles in the healthcare system. There are a number of issues he says contribute to lack of knowledge amongst doctors, including various points of bias and the inability to interpret and convey medical evidence and statistics. In addition, there seems to be a “culture to do more” in the UK, as payment by results can be an incentive to overuse healthcare resources. This means unnecessary spending for the NHS and unnecessary risk for some patients.
Relaying available evidence to patients is vital for allowing an informed patient decision. Unfortunately, many healthcare professionals are currently failing in this area, Dr Malhotra notes. He uses the example of coronary stents (angioplasty), which have been shown via randomised controlled trials not to reduce risk of heart attack or prolong life, yet they carry a risk of causing a heart attack, stroke or death. Ensuring that patients are privy to the lack of benefit may allow them to focus on more important lifestyle interventions that do actually help. Indeed, a JAMA internal medicine study found that the proportion of patients opting for angioplasty fell from 69.7% to 45.7% when the lack of prognostic benefit was explained to them.
Doctors themselves can often misunderstand health statistics, again preventing properly informed patient decisions, however, the doctors are not entirely to blame for this. Dr Malhotra explains that studies, even in high-profile journals, often present intervention benefits as ‘relative risk reduction’, whilst presenting the risk of harm of the intervention as ‘absolute risk’, framing the intervention misleadingly effective and safe. This technique, known as mismatched framing, can deceive laypeople and healthcare professionals alike.
One of the best examples of controversy in current medical literature is the use of cholesterol-lowering statins in the prevention of cardiovascular disease. Dr Malhotra discusses the literature at length, explaining how the benefits of statins are often exaggerated whilst the risk of side effects is downplayed. For example, a study in the BMJ found that 140 people at low risk of cardiovascular disease would need to take a statin every day for five years for one non-fatal heart attack or stroke to be prevented. Meanwhile, around 20% of patients taking statins will suffer unacceptable side effects. Dr Malhotra insists that this kind of information must be conveyed to patients before any decisions on treatment are made.
Unfortunately, bias is built into much of the published research, which can be cherry-picked or ‘massaged’ to appear more positive. This bias is largely driven by the interests of the pharmaceutical industry. As Dr Malhotra explains, pharmaceutical companies have an obligation to make a profit and generate dividends for shareholders, but are not legally required to sell consumers the best available treatments. Labs receiving funding from pharmaceutical companies are likely to produce results in agreement with their agenda for obvious reasons.
Dr Malhotra highlights the ethical responsibility of doctors to reduce wastage of medical resources whilst helping patients to make an informed decision on their healthcare. He also notes that the most effective intervention in secondary prevention of heart disease is the Mediterranean diet, which is high in healthy fats. Dr Malhotra finishes by explaining that focusing on treatment with drugs, such as statins, detracts focus away from the arguably more important diet and lifestyle changes which have the potential to save the NHS money whilst improving patient health.
