O paradigma do diagnóstico precoce na prevenção das doenças crônicas.

Abstract

The objective of this thesis is to identify and discuss the merits and shortcomings of the preventive strategy known as screening - the systematic search for cases in an asymptomatic high-risk subpopulation. And do this in light of new knowledge and technologies now available in twenty-first century; the needs of an older population, more urban and subjected to different stressors: the current reality of health systems (more specifically of our Sistema Único de Saúde ) and the finite availability of funds for its financing. The group of diseases investigated was that of Chronic Non Communicable Diseases - especially atherosclerotic cardiovascular disease and lung cancer. The thesis was written as an academic essay based on a narrative review. The medical literature has changed the boundaries that define major diseases related to atherosclerosis, with great impact on the calculation of their prevalence. The decrease of the boundaries that define hypercholesterolemia, in relation to the total serum cholesterol from 240 to 200 mg / dl added over 42,647,000 people to the group of patients (+ 86%). The diagnosis and treatment of this population group is called overdiagnosis and overtreatment. The use of predictive equations may be overestimating the cardiovascular risks in more than 150%. This strategy may have little impact on reducing the disease burden of a population in clinical phase and can lead to over-utilization of health services and thus reduce its efficiency. The overdiagnosis of breast cancer in a screened population is about 11-19%. It is estimated that it's necessary to track 400 women aged from 50 to 70 years of age, with bi-annual mammograms, for more than 30 years to prevent one death. For each breast cancer death prevented, about 3 cases of overdiagnosis will be identified and treated. With the emergence of new therapeutic resources in the last 40 years, the five year survival rate for breast cancer has been increasing, reaching 85% in developed countries and 60% in developing countries. This gain undermines the efficiency of the screening strategy. The assimilation of new diagnostic technologies to this process still haven t been supported by the medical literature.