Selective screening: Theory and practice based on high risk groups of cervical cancer

Abstract

Using data taken from the organised mass screening system in Finland, risk indicators of cervical cancer were identified in order to define a high risk group which could then be used for selective screening of cervical cancer. Single risk factors classified at best 39% of the cases into a high risk group of 8%. A combination of risk factors by different statistical methods was applied, but the results were essentially the same. In order to find a high risk group small enough to yield a reduction in costs, the number of cases originating from the low risk group was increased. Theoretical calculations showed that for selective screening to be effective, the risk of disease in the high risk group relative to that in the low risk group must be greater than that implied by current knowledge of cervical cancer epidemiology. It was concluded that selective screening has only a limited applicability.