Epistemology VI: Epidemiology

Epidemiology originally largely meant studying how infectious diseases spread, and that ' s still a major concern of epidemiologists. However, it also includes the study of any and every environmental or behavioral factor affecting human health. For example, the finding that smoking tobacco causes lung cancer (not to mention a bazillion other diseases) is an epidemiological finding.  Epidemiology is largely an observational science, given the ethical prohibition against exposing humans to potentially hazardous conditions for experimental purposes. That ' s not to say it hasn ' t been done, with the victims being especially vulnerable people, but it ' s no longer condoned. And given the complex associations and interactions among elements of the human environment and behavior, it is usually very challenging to convincingly establish causal relationships. That ' s why the tobacco companies could hold out so long against the conclusion that their products were deadly, although truth be told they continued to deny it long after they knew it to be true.There are just a few basic epidemiological study designs. They differ in time, cost and inferential value, so investigators have to balance the tradeoffs among these. The original finding of a link between tobacco and lung cancer was based on what ' s called a case-control study. The investigators found a bunch of people with lung cancer, and people without lung cancer who were otherwise similar in age and gender. Then the...
Source: Stayin' Alive - Category: American Health Source Type: blogs