Pap tests, like other early detection tests, are not 100 percent accurate. Estimates of the false negative rate range widely. In addition, new automated aids to reading and checking Pap tests and new ways to collect the specimens have been developed with the aim of reducing the false negative rate. The FDA has approved the marketing of several of these technologies. Some physicians and laboratories have begun to use them while companies continue to refine them.
Little data are available on their cost effectiveness.
Regular Pap tests help counter the problem of false negatives C i.e., if an abnormality is missed on one test, it is likely to be found on the next before it has progressed to cancer. After three or more consecutive annual exams with normal findings, the Pap test may be performed less frequently at the discretion of the physician, according to the ACS guidelines. There is no upper age limit for Pap tests. As of January 1998, Medicare covers Pap tests once every three years for all Medicare beneficiaries. Many women still do not have regular Pap tests.