What is Epidemiology?

Epidemiology is defined as the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.

But what does THAT mean?

Epidemiology is the study of what makes people sick.  But it's different than being a doctor or physician.  Epidemiology looks at sickness on a population scale.  Where a doctor cares about and studies sickness in an individual person, an epidemiologist cares about and studies sickness in large groups of people...like, for instance, the whole population of Hartford.

Epidemiology is derived from the word EPIDEMIC, which many people understand to be a rapidly spreading outbreak of contagious or infectious disease.

So, to many people, epidemiologists are people that study epidemics.   To an extent, that's true.  The epidemiologist here at the Hartford Health and Human Services Department is called on when an epidemic takes place in Hartford.  That epidemic is usually related to food, like when a whole lot of people all get sick from eating the same infected or poorly cooked food.  Thankfully, though, things like that don't happen every day.

So what does an epidemiologist do when there are no epidemics going on?

Like we said earlier, epidemiologists look at disease or illness on a population scale.  But you can't examine or give physicals to everyone in Hartford.   For epidemiologist to do their work then, they have to look at data.

Data is nothing more than information.  Of course, it helps if that information is organized in one way or another.  That way, it makes it easier to look at.

Sources of data can be practically anything you can think of.  Some of these are:

In many cases, we will create our own sources of data such as surveys, for example.

These data then let us try and look for differences in groups of people contained within the data.  For example, is there a difference between people who smoke and those who don't smoke?  Epidemiology is the science that allowed the Surgeon General to determine that smoking was bad for your health in the 1950's.

So, when epidemiologists aren't working on epidemics, they're looking for patterns in data.

What do they do when they find a pattern?

In many instances, they get reported in scientific journals.  Many of these articles make the news, and may change the way you live your life.  For example, studies that linked fatty foods to heart disease were epidemiology.  And studies that show that pregnant women should supplement their diet with folic acid are epidemiology too.

But just as often, there studies are used to set priorities and make policy decisions--like where public health funds should be spent, and where they should not be spent.

A whole different branch of epidemiology is used to find patterns in data that prove that all the prescription and over-the-counter drugs that you take are safe.  These are called clinical trials.

OK, now what about us here in Hartford?

We have plenty of data, from many sources, which can help us take a look at the health of Hartford.  Certain data is required to be kept, on reportable diseases and such, and much of this information is kept at either the local or state Health Department.  We also have some information on the clients that use Hartford Health and Human Services.  We also have information that we can get through our community health partners.  Included in this data is information from the Hartford Health Survey that began in 1997.  The survey is done every three years.  The Hartford Health Survey 2003 has been completed and is available at www.hchp.org.  The survey asks randomly selected Hartford residents about their health, from any conditions they might have had, to whether or not they had health insurance, to whether or not they liked their doctor, to issues that worried them in their neighborhood.  A typical graph of this data is shown below.