§ Mr. WrayTo ask the Secretary of State for Social Services what is the percentage of failure in the detection of cervical cancer by the present test system used by his Department.
§ Mrs. CurrieEstimates of the false negative rate for cervical smear tests vary widely. In some cases an inadequate sample of cells is captured by the person taking the smear; in others cellular changes may be missed by the laboratory in which the smear is examined. That is why health circular (88)1 issued in January 1988 includes guidance on the quality of smear-taking and on internal quality control and external quality assessment in laboratories.
No screening test or screening programme can achieve 100 per cent. accuracy. Nevertheless, studies by the World Health Organisation's International Agency for Research on Cancer show that women who have a smear test every five years between the ages of 20 and 64 are 84 per cent. less likely than unscreened women to develop invasive cervical cancer.