Quality of Life Assessment has progressed considerably since the publication of the first highly acclaimed edition of this book in 1998. Quality of life has now become an indispensable outcome measure in many randomised clinical trials and other studies. Thus, it is timely to provide not just an update, but a completely new edition that reviews the current state of art and also discusses topical issues including areas where active research is in progress. The first section discusses the development and evaluation of generic and disease-targeted questionnaires. Having decided the items to be included the thrust of the next section covers how to convert these into usable forms. Section 3 addressing analysis and the methods of analysing studies with missing data is followed by chapters on interpretation of results and exploring the role of single-item questions. The final section of the book looks beyond the individual clinical trial and how we can use clinical trial and other data to make macro-decisions. A strong international team of experts cover a wide range of topics, emphasizing new and innovative approaches that are of practical and clinical importance, reviewing the current state of the art and illustrating the benefits and potential of health related quality of life assessment in clinical trials.