Introduction to epidemiology

We can define epidemiology as the study of the determinants and distribution of health-related states. We will study how a pathogen is spread into a population such as common flu or influenza AH1N1. This is particularly important because an outbreak can cause severe human and economic loss. In the following screenshot we can see the interface of Google Flu Trends (GFT), which uses an aggregated Google search data to estimate flu activity:

We can find the GFT data freely available from its website. With this time series we can implement statistical methods for descriptive epidemiology or causal inference. The GFT has been extensively compared with the seasonal influenza data of the Center for Disease Control (CDC), which is obtained with typical surveys and medical reports, providing similar results.

We can find the Google Flu Trends data freely available at http://www.google.org/flutrends/us/#US.

And the seasonal influenza (Flu) data can be found at http://www.cdc...