Speaker
Hein Stigum, a Senior Researcher at the Department of Epidemiology, National Institute of Public Health.
Abstract
Selection bias is a central concept in epidemiology. We will show that there are two types of selection biases, with different structure and different properties.
We will continue with the least well understood of these types, show examples, and develop limits for size of the bias. We will also show how risk ratios, odds ratios and risk differences react differently to selection bias.