The book that health professionals turn to for a full and clear explanation of the principles of evidence-based medicine. The author's descriptions of clinical research papers and how to critically appraise them are so simply presented as to be understandable by readers at all levels, from student to specialist. Chapters on searching the literature and implementing the evidence provide guidance on using evidence-based medicine in clinical practice. This fourth edition retains the winning style, and takes in the recent developments and shifts of emphasis in evidence-based medicine and now includes: * Thoroughly revised and updated chapters on searching, qualitative research, systematic review, and implementing evidence-based practice *2 new chapters on quality improvement and the emerging field of complex interventions This new edition will be welcomed by those who teach and those needing to learn the basics of evidence-based medicine.Praise for previous editions ''One of the greatest aspects of this book is the section relating to searching the literature and whilst we may think we may all practise this on a fairly regular basis under the assumption that we do a pretty decent job of it, this section holds the key to excelling.'' -From a review in Urology News ''This clear and concise book provides an excellent starting point for those interested in finding their way through the medical literature.'' -From a review in Palliative Medicine