Saturday, May 02, 2009

I (heart) epidemiology

I (heart) epidemiology. Careful analysis of the actual numbers in a public health crisis is a great antidote to the passionate and scurrilous dissemination of misinformation and fearmongering. This latest so-called "pandemic" is a great case in point. Sure, so-called "swine flu" (influenza A(H1N1)) has spread to a number of countries around the world (15 at last official count), but the actual "body count" is still quite small and the actual health impacts (other than in Mexico itself) have proven to be quite mild.

If it was up to me [Imagine that, me running the world!!], I would reserve the term pandemic for significant global health impact, or at least have levels of health impact, such as death, long-term harm, severe short-term suffering, highly contagious, etc., with the bottom category being what we have outside of Mexico right now: mild.

The whole point of epidemiology is to avoid the need to debate public health and to have some objective measurements so that the discussion will be less about rhetoric and more about actual reality.

Numbers tell the real story. Sure, the numbers can and do change, but so does the actual reality. The whole point of the numbers is to track reality. What else is there that is worth discussing?

Sure, we all want to predict the future, but the numbers are actually our best available tool. Project into the future using current numbers and then see how things play out and then adjust our model of reality accordingly.

The heart and soul of the concern about pandemics is the worry that an epidemic will go exponential. That means it takes a certain amount of time for the number of infected to double and then each subsequent elapse of that same time interval will result in 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, and so on times as many infected. As long as an epidemic does not go exponential, it will usually just level out and actually begin to dissipate, such as what we may be starting to see right now.

Some people make a big deal about the fact that the authorities have not detected and confirmed all cases, but that is not a problem. All we really need is a sample of the total infected and then we can monitor that sample to get a sense of the health impacts and growth rate.

Epidemiology is all about evidence-based medicine. Rumors and unconfirmed reports will never be a valid substitute for real data and real facts.

The Wikipedia article on epidemiology tells us that:

Epidemiology is the study of factors affecting the health and illness of populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine. It is considered a cornerstone methodology of public health research, and is highly regarded in evidence-based medicine for identifying risk factors for disease and determining optimal treatment approaches to clinical practice. In the study of communicable and non-communicable diseases, the work of epidemiologists ranges from outbreak investigation to study design, data collection and analysis including the development of statistical models to test hypotheses and the documentation of results for submission to peer-reviewed journals. Epidemiologists may draw on a number of other scientific disciplines, such as biology (to better understand disease processes) and social science disciplines including sociology and philosophy (to better understand proximate and distal risk factors).

To be crystal clear, epidemiology exists solely to support the interests of public health and preventive medicine. Anybody who tries to claim or suggest approaches to public health and preventive medicine without paying heed to the concepts of epidemiology is doing the public a disservice.

Spreading misinformation, flaming fear, and making wild claims is never in the interest of the public. Some individuals or groups may seek to exploit epidemics for their own agendas and power plays, but that is not about protecting and promoting public health.

-- Jack Krupansky

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home