[When should a disease be diagnosed early and whose disease?].
Screening programs may seem useful and effective. However, in many cases the benefit is not clear and may actually do more harm than good. Each time a clinician asks for an early diagnostic test, the scientific evidence and the attributed risks need to be defined. The effectiveness of any early diagnosis test relies on the characteristics of the test itself, the disease to be ruled-out, and the side effects of the test. Such effects may be physical and emotional and the outcomes may be against the well being of the patient. In general, if an early diagnostic test does not lead to improvement in the survival and/or morbidity of patients, its utilization is not justified.