Current issues of ACP Journal Club are published in Annals of Internal Medicine

Resource Corner

Clinical Epidemiology: How to Do Clinical Practice Research


ACP J Club. 2006 Jul-Aug;145:A11. doi:10.7326/ACPJC-2006-145-1-A11

The first thing I noticed when I opened this book was the lack of similarities between this and the previous edition. The authors are the same (although the order of their names has changed), the evidence “cube” is still on the front cover, and the title is still Clinical Epidemiology. However, the subtitle gives the clue to the major change: from “A Basic Science for Clinical Medicine” to “How to Do Clinical Practice Research.” This book couldn't be any more different from the previous edition: gone are the statistics (as it states “this book isn't about biostatistics,” and the authors “apologize” for the oversimplification in terms of the numbers); also gone is the use of clinical research in clinical practice (this “how to use” research is the domain of several good evidence-based medicine [EBM] books).

So what is this book about? As implied by the title, the new edition is clearly focused on how to do clinical practice research. It is aimed at investigators at any stage of their career “from beginning students to seasoned investigators” and is a culmination of the authors' experiences in undertaking clinical research over the past 40-plus years. In terms of longevity the award would go to David Sackett, having been an internist since 1961. The enthusiasm the authors have for clinical research is apparent throughout the book and, as they state, they jumped at the chance to get back together to produce a practical book on how to generate the E in “EBM.”

The book is split into 2 sections: the first is about performing clinical research and includes chapters on finding information about the burden of disease, testing quality improvement interventions, evaluating diagnostic tests, prognosis, causation, and generating outcome measures, especially for quality of life.

In the preface, the reader is instructed not to read the book like a novel, but rather to dip into chapters as required. I ignored this advice and it was well worth it! So how would I use this book now that I have read it? First, I would advise anyone undertaking a systematic review for the first time to view the chapter by Brian Haynes as compulsory reading. Like all the chapters in the book, you are given a checklist for performing a particular piece of research, and the chapter guides you from asking your research question through to planning your budget.

At 184 pages, Chapter 4—an introduction to performing therapeutic trials—is the longest chapter in the book and is crammed with information for those considering undertaking a clinical trial. It opens with the tactics to start your trial and uses sample scenarios and studies in which Dave Sackett has been involved. Again useful checklists are provided throughout: the checklist for participants has 11 steps, and each step is explained in detail. Among the helpful and interesting tips for those undertaking RCTs is these: did you know that 12 strategies exist for increasing patient participation in trials? Or that casting lots by the roll of a dice to create comparable groups, thus to avoid confounding, has been done for centuries? Also covered in this section are ethical issues, an approach to writing up your randomized controlled trial for publication, large trials, small trials, and nondrug trials. Actually, there are some statistics in this book, but apparently there is only 1 formula you'll ever need. It looks like this:

Confidence = (signal/noise) ×√sample size

The second (and shorter) section is about becoming a clinical researcher, which is an equally fascinating read. The first chapter on becoming a successful clinical investigator proposes 3 determinants of academic success: mentoring, creating periodic lists, and time management. I found the section on preparing a research protocol to improve its success useful, but this is the 1 chapter—at only 11 pages—where I wanted a bit more. This probably reflects the time and effort required to get any of my protocols anywhere near worth funding.

The chapter on preparing reports for publication cheered me up about my own writing. How? By Gordon Guyatt and Brian Haynes stating that they commit to editing and re-editing their own writing several times. In fact, they state that 7 people reviewed the chapter on preparing reports. They give useful rules for writing—for instance, to achieve clarity keep your paragraphs down to 5 sentences or fewer—therefore, no more full stops in this paragraph keeps to the rule!

For current researchers and those considering doing research, this book is a thoroughly good read and worth keeping on your shelf. For those looking for information on how epidemiology affects clinical practice, then you still can't beat the second edition.

Carl Heneghan, BM, BCh, MRCGP
Centre for Evidence-Based MedicineUniversity of Oxford
Oxford, England, UK


Methods/Quality of Information: 5 of 5 stars

Clinical Usefulness: 5 of 5 stars

Clinical Epidemiology: How to Do Clinical Practice Research is available online at for U.S. $49.95 and includes a bonus CD-ROM bound into the book.