Epidemiology kept simple An introduction to classical and modern epidemiology By Burt Gerstman Wiley 301 pages £25.95

In addition to being an excellent source of expert information on epidemiology and how it has been applied in a variety of settings and studies, this new book helps to demystify the key contemporary and historical problems that have beleaguered it.

Epidemiology integrates many different disciplines, from biostatistics to public health policy development, and environmental health to occupational health and safety.

The first part of the book defines the importance of the scientific method and differentiates between health problems that are epidemic, endemic or pandemic.

The book's main strength is the author's effective use of clear examples of epidemiology in practice. Gerstman shows readers that the history of epidemiology as a discipline is critical to understanding its unique multidisciplinary approach.

Also, the discipline's history has shown that preventive measures for diseases have been discovered as long ago as 44 years before the microbiological causes were known in diseases such as scurvy, pellagra, smallpox, cholera, yellow fever and oral cancer. Readers are introduced to leading figures who influenced epidemiology: the achievements of people like John Snow, John Graunt, Edward Jenner, Emile Durkheim, Jakob Henle and Louis Pasteur are outlined briefly. Although the book is written mainly for a North American readership, sections of the book, which include some excellent case studies and self-test exercises are equally applicable to Britain.

The case study investigation into food-borne disease outbreaks is particularly relevant in light of the continuing difficulties that have arisen in Britain with recent E coli and salmonella-related health scares.

The chapter entitled 'From Association to Causation' uses classic British studies by Doll and Hill to examine the relationship between smoking and lung cancer.

One case study looks at the complexities involved in screening for antibodies to HIV. Another chapter outlines how one can examine the frequency of a disease by looking at its prevalence and incidence.

There is also an informative section devoted to study designs and the advantages and limitations of cross-sectional, cohort and experimental studies.

Other chapters in the book deal with measurement of relative risks, estimation, hypothesis testing and elimination of selection bias in a non-esoteric manner.

However, as a prerequisite, readers will need a basic knowledge of research and statistical methodologies to benefit fully from the wealth of information inside.

The author makes epidemiology an accessible subject for all and succeeds in simplifying potentially complex topics with novel examples such as using the Poisson Distribution to identify the possible outbreak of a rare form of cancer. Overall, Epidemiology Kept Simple may help to encourage those who work in the health service to question research findings in a rigorous, evidence-based manner while steering clear of the ideological and political distractions which can cloud the uptake of scientific evidence within the NHS.

Glenn A Williams

Research officer, Parkside Health trust.