Interpreting the Medical Literature.

From the title Interpreting the Medical Literature, readers might expect to find another book like the User's Guides to the Medical Literature [1, 2] and question the necessity of such a similar volume. The purpose of Gehlbach's book, however, despite its title, is to provide basic descriptions of various research study designs that readers can then use to interpret the medical literature. While intended originally for medical students and clinicians, the book is relevant to any researcher, practitioner, or student in the health sciences. This fourth edition updates all previous ones by updating its references and examples, as well as expanding on the content.

The initial chapter as well as the final two chapters stay true to the title by discussing the reasons to read articles, the problems caused by information overload, the approaches to skimming and then analyzing articles, the purposes and usefulness of different document types (e.g., case studies versus letters to the editor versus reviews), and the need for critically reviewing and interpreting the material. Like the other chapters, these introductory and concluding sections offer useful tables and checklists as well as references for follow-up.

Five chapters cover study design, one chapter covers collecting data, and five more cover analyzing and interpreting data. Each chapter begins with an overview of a concept followed by an in-depth discussion including the benefits and challenges of each method. Numerous “real life” examples along with tables and diagrams allow readers to begin applying the theory while reviewing the literature and to judge for themselves if authors have used and identified methods correctly. Additionally, Gehlbach includes discussions of ethics, challenges, and implications in choosing different research study designs. Summaries at the end of most chapters contain checklists or lists of questions for readers to use when analyzing studies in the literature. These summaries and checklists are among the most useful sections of this book.

Despite a somewhat pontifical tone in the introductions and conclusions of each chapter, Gehlbach's enthusiasm for the subject matter shines through in the discussions. He clarifies murky terminology and makes research design and statistical analysis understandable to those with little or no experience. He uses both analogies and real life examples to make the subject matter more readable.

Embedded in the preface, the statement “the emphasis remains on a basic understanding of study design, on the way subjects are selected and organized for study and the implications for the validity of results” (p. ix) summarizes the approach and strength of this book. Interpreting the Medical Literature meets its stated purpose.