ABSTRACT
This chapter provides an introduction to the self-controlled case series (SCCS) method, focused on its epidemiological rather than statistical aspects. It aims to provide a broad overview of the method: its genesis, the epidemiological questions it can help to address, the ideas behind it, the data required, how it can be used, and the assumptions it is based on. In 1992, a team of microbiologists and epidemiologists, along with a statistician, met in London to discuss a potential problem with the measles, mumps and rubella vaccine, which had been introduced in the United Kingdom in 1988. A convenient way to introduce the SCCS method is to consider what epidemiological questions can be answered from data only on cases, that is, individuals who have experienced one or more events while under observation. The epidemiological parameters that are estimated in a SCCS study are relative incidences associated with exposure or age.
