The success of epidemiology
Recently I had a conversation with a dear friend of mine asking if epidemiology has run its course: all of the low hanging fruit have been picked, and the remaining issues are likely unsolvable. This friend felt epidemiology was moving from major breakthroughs to only incremental improvements that were more scientific advances than public health advances. Is this true? Probably not, otherwise so many people would not enter this discipline. So what can be done to motivate us as researchers? From time to time it is worthwhile to examine the contributions a field has made.
The health of the public has markedly improved in the twentieth century, through direct and indirect benefits from health-related research. Life expectancy has increased by an average of 30 years, with a much larger proportion of the population living to older ages. At the close of the twentieth century the U.S. Centers for Disease Control and Prevention (CDC) released a list of ten notable public health achievements (unranked), including:
Each and every one of these achievements that resulted in a decline of morbidity and mortality started as the recognition of a public health problem. Interventions have included behavior modification, improved food and water, access to health care, and legal mandates, and were often the byproduct of research at the local, state, and national levels. The culmination of this research directly led to 25 of the 30 years increase in life expectancy. In most, if not all of these achievements, epidemiology (the science of public health) provided the foundational knowledge to measure the disease burden and changes in outcomes over time. The physician now armed with knowledge about tobacco, vaccination, breastfeeding, and so on, can help the patient achieve a longer, healthier life. In order for physicians of the future to maintain these positive trends requires public health research conducted in the present.
Are all of the major public health issues known? Of course not. There are behavioral, structural, and environmental risk factors for disease that still need to be explained. Take, for example, the Hispanic paradox, or any number of racial disparities in health (HIV infection, premature birth, etc., etc.). There are neighborhood effects (aka contextual differences) yet to be elucidated. We need to look back to the field's achievements to motivate ourselves for the future, and start asking daring questions and become more engaged as public health advocates. At the close of the twenty-first century, public health practitioners can only hope to mirror these remarkable successes.