Disease Prevention Checklist

In theory, if I could afford it, what would be the harm in getting a screening test for every condition I'm concerned about?

Screening tests have uncovered millions of cases of disease that were treated successfully. These tests became popular a few decades ago, when routine physical exams began to include all kinds of tests for the seemingly healthy person, "just to see." Since then, computer analysis of medical data has made it possible to do a much better job of assessing the real outcome of these tests, and of knowing which tests really help when a person does not have symptoms of the condition in question. Scientists have concluded that screening tests should not be undertaken too casually. If the tests are not accurate, they can cause anxiety, needless expense, and, more important, the need for follow-up procedures that might be risky to your health, or at least very uncomfortable, not to mention expensive.

If you have no symptoms, the harm of getting a screening test for every condition that you're worried about is that you probably are unable to judge the ultimate benefit versus risks of getting the test. Two factors that greatly affect how worthwhile it is to get a screening test are specificity and sensitivity. Specificity is the ability of the test to find the condition that it is screening for. For example, results should be negative if the test is searching for breast cancer but there isn't any cancer. If a mammogram finds lumps, but they are not cancerous, then the test has not been specific for breast cancer. You might then have to undergo procedures that produce nothing important and possibly make you worse off than if you hadn't had the mammogram. Sensitivity is the ability of the test to identify the condition in question. That means results should be positive if you do, indeed, have the condition in question. If a mammogram fails to catch the kinds of lumps that are serious, then it has not been sensitive for breast cancer.

A similar concept is that of "false positives" and "false negatives." A screening test which is frequently abnormal when the person truly has no disease has a high "false positive" rate. A test which misses a disease when it is really there has a high "false negative" rate.

All blood tests "trade–off" between sensitivity and specificity, high false positive rate or high false negative rate, depending on what number is picked as the "abnormal level." Other tests, such as mammograms and Pap smears, depend on the standards established for interpreting the test and the ability of the interpreter to meet the standards, which in turn can depend on level and standardization of training, and on number of years of experience.

Deciding if a screening test is to be recommended is not, therefore, an easy task. RealAge has based its recommendations on the best science available, but also tells you where there are controversies or inadequacies associated with specific test so that you, in conjunction with your health care providers, can make an informed decision about the usefulness of a screening test for you, and how often you should receive the test.