Rules of thumb for positive and negative test results

Background It is well known that tests are not 100% accurate at classifying individuals. The actual condition of an individual(e.g. diseased, or not diseased) does not coincide with her test result (positive, or negative). Nevertheless, it is often presupposed, as a rule of thumb, that individuals with negative results can be “ruled out” if screening test is highly sensitive and “ruled in” if screening test is highly specific. This has led to...