Epidemiology and public health intelligence

This chapter provides an introduction to epidemiology. It covers the key epidemiological concepts such as bias and confounding, as well as providing an overview of the nature, history and types of epidemiology. The main epidemiological study designs are described, including case series, ecological, cross-sectional, case-control, cohort, randomised controlled trial and systematic review. The advantages and disadvantages of each are summarised, and some of the ethical issues in doing research are considered. The 'hierarchy of evidence' framework is contrasted with an approach which recognises the most appropriate study design to answer different questions about population health. This chapter will examine the role of epidemiology in public health intelligence and develop students' or learners' knowledge and skills to carry out thorough, rigorous and meaningful research and investigation relevant to public health. After reading this chapter you should be able to: • Define epidemiology and differentiate between descriptive epidemiology and analytical epidemiology • Describe the basic study designs, principles and methods used in epidemiology • Explore key issues related to the design and conduct of studies • Recognise the role of epidemiology in public health intelligence.