Disappointed with the texts used to teach introductory epidemiology to postgraduate students, Bhopal published his own book based on a review of 25 introductory texts in 2002.^{( 1 )} In that well-received first edition, Bhopal explained the underpinning concepts of epidemiology using plain language and illustrative examples; he further aimed to reinforce understanding by including practice questions and answers at the end of each chapter.

The primary aim of this second edition was to improve upon the first in several areas. In contrast to the first edition, the author has expanded the question and answer sections and further simplified the language to accommodate those students whose main language is not English. He has also added introductions to particular fields, including genetic epidemiology and the purpose of reviews (narrative, systematic and meta-analysis).