ABSTRACT

Patients want to know why they contracted a disease. Politicians and health planners want to know why there are so many cases of cancer, injury, heart disease or infection in the community and which preventive measures should be put in place. The answers to these questions should be logical and supported by the best evidence available:

For this kind of logical argumentation, a clinician needs evidence:

Clinical practice:Logical discourse:Evidence: ‘You are suffering from of a rather serious liver disease’

• That the patient really has liver cirrhosis (from the field of diagnosis; see Chapter 6); • That liver cirrhosis is caused by alcohol abuse (from the field of etiological research as

outlined in this chapter); and • That stopping alcohol consumption will improve the patient's health and survival (from

studies of health intervention and prognosis as outlined in Chapters 9 and 10 of this text).