The renewal of the National Cervical Screening Program

I question that clinicians and the public may be reassured that the evidence underpinning the renewal of the National Cervical Screening Program (NCSP) is sound.1 A fundamental aspect of the sensitivity of a screening test is the definition of the disease of interest that the test seeks to detect. For cancer screening, it is disease that will progress to life-threatening cancer and not the sensitivity to detect disease that only may progress to cancer.2,3 It is a very common but profound error to consider these equivalent,2 particularly when comparing two tests that measure different aspects of the disease process. Overdiagnosis and regression biases are avoided by using the interval cancer method to estimate sensitivity.2,3