# Berksonian Bias

When we take the sample we have to assume that the chance of admission to hospital for the disease is not affected by the presence or absence of the risk factor for that disease. This may not be the case, especially if the risk factor is another disease. This is because people are more likely to be hospitalized if they have two diseases, rather than only one.


1. Sackett, D.L. (1979). Bias in analytic research. Journal of Chronic Diseases 32, 51-63. ^