Hail the heroes who brave front line

As some epidemiologists avoid engaging directly in public-health work, Douglas Weed says respect those who show no fear

Debates in academia are common and often not relevant to anyone outside our ivory towers. But there is one issue that everyone who cares about their risk of disease should understand. It is a debate among the academic epidemiologists about their role in society. It is a debate about this simple question: who is responsible for preventing disease?J On one side are the traditionalists - the epidemiologists who see their professional duties as starting and ending in public-health problems. Their heroes - John Snow, Joseph Goldberger, and Elizabeth Lane Claypon - did the scientific research and then acted on it. They practised prevention, translating science into public health action.J On the other side of this debate are the modern epidemiologists. They see their societal role beginning and ending in pure science. Unsullied by the difficult but necessary choices involved in translating evidence into action, they leave application to others.

"Just the facts" is their motto. Epidemiologists, they claim, should not mix science with messy real-world problem-solving. The science is difficult enough, relying as it does on observational studies rather than controlled experiments.

Its methods are so often challenged that it seems better to stay anchored to the ideals of truth and objectivity than to extend epidemiology's role into the realm of values and vested interests. In the end, they argue, science will suffer if its practitioners practise public health.

The stakes of the debate could not be higher. Across the globe, millions die prematurely and unnecessarily of potentially preventable diseases - influenza, heart disease, cancer and diabetes as well as diseases such as Alzheimer's and strokes that, ironically enough, rob us of our unique gifts: intellect, creativity and rhetoric, the essential components of a juicy academic squabble.J To be fair, public health decisions about prevention are complex and difficult, and many stakeholders are involved, not only epidemiologists.

But what makes these decisions so tough is that they are full of uncertainty. And so it is almost frightening that those who have the best understanding of scientific uncertainties are trying so hard to distance themselves from using their knowledge in public health.J For a traditionalist such as myself, the modernists have it exactly backwards. There is no stronger motivation for improving epidemiology's scientific methods than to use them in real-time decisions. There is no better way to sort out the causes of diseases than science itself; and there is no better reason to improve the science than to prevent the diseases that rob it of its children, its geniuses and its simple folk, all of whom are equal in the eyes of whichever god you choose to worship - yes, even the one presiding over the altar of scientific truth.

So keep the epidemiologists in harm's way, where their heroes have always stood, demanding action or inaction as the evidence and their values and their judgment required at the time.J Can you imagine Snow walking away from the Broad Street pump after he became convinced that it was gushing choleric water? Would Goldberger be a hero today if he had never tried to prevent the dietary cause of pellagra when his scientific papers were published?

The heroes of epidemiology recognised that the end of epidemiology - its final aim - is not scientific truth but rather the prevention of disease.

Ignore this, and the discipline will not improve. Indeed, it will stagnate, too distant from the societal ends it purports to study. Ignore the end of epidemiology and it will, as a profession devoted to the public's health, end.

A debate such as this one is not resolved in a flash of rhetoric. It needs to be understood by those with the most to gain and the most to lose. It needs to be heard by those not privy to the academic's ivory tower: the public.

Douglas L. Weed is chief of the office of preventative oncology at the National Cancer Institute in the US.