Screening tests
What are screening tests?
Most tests, such as blood tests and X-rays, are done to help discover, or confirm, a doctor's suspicions about the cause of a particular symptom experienced by a person.
Sometimes tests are conducted on apparently well (asymptomatic) people, just in case they have a problem.
Tests done under these circumstances are known as screening tests. Perhaps the best known screening test is the Pap smear, which tests women who have no obvious symptoms for cancer, or potential cancer, of the cervix.
Simple guidelines for screening tests
All tests cost money and for this reason it is important that screening tests are done only in appropriate circumstances. Here are some simple guidelines for a screening test.
- The condition being tested for should be common, and serious enough, to affect a person's quality or length of life.
- There should be a period of time when the condition is asymptomatic (no signs or symptoms) or there should be an early symptomatic stage.
- There must be an effective way of treating the condition.
- Treatment started during the asymptomatic period or in the early stages of the condition must produce better results than if it had been started later on.
- The test should be simple, safe and well tested.
- The test should be acceptable to the population being tested.
- Screening should subsequently result in improved quality of life or length of life for those people diagnosed with the condition.
Useful screening tests
While it is naturally tempting to want to be checked for unknown problems, this is not always possible, or justified. However, some screening tests are very valuable for the whole community.
A simple, once-a-year, blood pressure test is a good example of a low-cost worthwhile screening test. As well as Pap smears, other screening tests include blood cholesterol level checks, blood glucose checks, bowel cancer screening tests (faecal occult blood tests) and breast X-rays (mammograms) in women. Current thinking suggests that screening men for prostate cancer and women for ovarian cancer is not justified, but there is some controversy about this and researchers are looking for new tests for these conditions.
Last Reviewed: 21 October 2009
- 1. The Royal Australian College of General Practitioners. Introduction. In: Guidelines for preventive activities in general practice (the 'red book'). 7th ed. Melbourne: The Royal Australian College of General Practitioners; 2009. Available from: http://www.racgp.org.au/redbook/i (accessed November 2009).
