There is an interaction between measuring and what is measured. Heisenberg's Uncertainty Principle is true for medicine and helps explain some confusing and changing health information. 
An infectious virus or idea plus a susceptible population can cause the flu, a riot or fake news. A study of the 2005 riots in France finds an epidemiologic explanation.  
In a 1965 address, epidemiologist Austin Bradford Hill introduced nine criteria that researchers should consider before declaring that A causes B. Here's a concise summary of his presentation.
Isn't it odd that Florida has so many people living with Alzheimer's? If Erin Brockovich was investigating the case, she probably would conclude that it's something to do with the water.
Over-the-top rhetoric is not only prevalent in our political dialogue, it is also commonly adopted by epidemiologists and journalists. Instead of Hitler, they compare anything they dislike to smoking.
A phylogenetic and epidemiological analysis suggests that people who died from Ebola possibly spread the virus to more people than those who survived.
Hollywood will make no sequel to Erin Brockovich, nor will Pacific Gas & Electric be reimbursed $333 million. However, after nearly 20 years the truth about hexavalent chromium has finally been revealed by California regulators.
The headlines all imply that nearly all football players who make it to the NFL will develop CTE. That couldn't be further from the truth. Here are four major reasons why.
Too much, too little, and just the right amount of sleep have been linked to death. Sorry. 
The national media is alive with the report; coffee intake is good for you! And evidently, the more the better. The data, of course, is a bit more – shall we say – nuanced.
Every scientific paper should be required to answer a simple question before it's published. So prior to considering whether ingesting too many polyunsaturated fats (e.g., fish and foods cooked with vegetable oil) will make women lazy, TV-watching diabetics, an elementary-school query must first be asked: Does that even make sense?
Public health is a field that's widely misunderstood, even by science journalists. That's because epidemiology is an inexact science, complicated by a large variability in the quality of the data it produces. Also, by its reliance on advanced statistical methods.