Enigmas of Health and Disease by Alfredo Morabia

Author:Alfredo Morabia
Language: eng
Format: epub
Tags: -
Publisher: Columbia University Press
Published: 2014-05-19T16:00:00+00:00

IS THIS SCREENING USEFUL?

The involvement of epidemiology in the evaluation of screening programs was another indirect consequence of post-1945 technological and therapeutic progress: the availability of effective treatments and screening tests.

Before we see why epidemiology was instrumental in introducing a new way of determining whether screening for a particular disease was useful, please pause here and answer this question: When is it worth it to screen people for diseases? Or, rephrasing the question in a lengthier way: When is it worth it to indiscriminately propose to people belonging to a specific gender and age category a specific screening test to detect the presence of a disease in its earliest stages, before the person even feels sick and before a doctor can identify it with a clinical examination? Most of us have undergone screening tests in the past and still do. Why?

Studies have shown that few people, including doctors, understand that mass screening is worth it when screenees (on average, as a group) are likely to die at an older age from the detected disease than if they had not been screened.16 Screening can be systematically offered only if it does help the screenees to live longer. Otherwise, it makes them uselessly aware of their ailment for a longer period of their life or, worse, submits them to the side effects of diagnostic procedures or avoidable treatments.17

The increased availability of effective treatments opened opportunities for screening. However, the habit of evaluating whether screening tests actually work is recent. Screening tests introduced before the 1960s were not evaluated. Doctors believed that the Bordet-Wasserman test for syphilis and the Papanicolau test for cancer of the uterus cervix worked, but there was no direct proof. These screening tests were easy to perform and to incorporate into the usual practice. This passive acceptance of screening changed in the early 1960s when an expensive and painful X-ray of the mammary gland, mammography, became available to screen for breast cancer: it was decided to determine first whether it prolonged life.

Chapter 13 discusses two RCTs of screening test efficacy: one that was deemed positive, suggesting that mammographic screening could prolong life (1963); another that was deemed negative, questioning the beneficial role of screening for the prostate-specific antigen to prolong the life of men suffering from prostate cancer (2009).

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.