Systematically developed statements which assist clinicians and patients to decide on appropriate treatments for specific conditions. These guidelines are attractive to health managers and patients because they are potentially able to reduce variation in clinical practice. This helps to ensure that patients receive the right treatment of an acceptable standard. In England & Wales, the national institute for clinical excellence (NICE) is developing national guidelines, with advice from healthcare professionals and patients, to improve clinical effectiveness of NHS care. Some doctors have reservations about guidelines because (1) health-care managers might use them primarily to contain costs; (2) inflexibility would discourage clinical innovations; (3) they could encourage litigation by patients.