0px; "> No one would doubt the importance of clinical trials in the progress and practice of medicine today. They have developed enormously over the last 60years, and have made significant contributions to our knowledge about theefficacy of new treatments, particularly in quantifying the magnitude of theireffects. Crucial in this development was the acceptance, albeit with considerable initial opposition, to randomisation – essentially tossing a coin to determine treatment allocation. Over the past 60 years clinical trials have becomehighly sophisticated, in their design, conduct, statistical analysis and the processes required before new medicines can be legally sold. They have becomeexpensive and requiring large teams of experts covering pharmacology, mathematics, computing, health economics and epidemiology to mention only afew. The systematic combination of the results from many trials to provideclearer results, in the form of meta-analyses, have themselves developed theirown sophistication and importance.In all this panoply of activity and complexity it is easy to lose sight of theelements that form the basis of good science and practice in the conduct ofclinical trials. Allan Hackshaw, in this book, achieves this with great skill. Heinforms the general reader of the essential elements of clinical trials; how theyshould be designed, how to calculate the number of people needed for suchtrials, the different forms of trial design, and importantly the recognition thata randomised clinical trial is not always the right way to obtain an answer toa particular medical question.As well as dealing with the scientific issues, this book is useful in describing the terminology and procedures used in connection with clinical trials,including explanations of phase I, II, III and IV trials. The book describes theregulations governing the conduct of clinical trials and those that relate tothe approval and sale of new medicines – an area that has become extremelycomplicated, with few people having a grasp of the “whole” picture.This book educates the general medical and scientific reader on clinical trials without requiring detailed knowledge in any particular area. It providesan up to date overview of clinical trials with commendable clarity.Professor Sir Nicholas Wald