Clinical impact of quality assurance in an organized cervical screening program

We have studied whether clinical monitoring of an established population register based cervical screening program could reduce the number of cervical cancer cases and if drawbacks in the coverage could be detected.

A total of 123 consecutive cervical cancer cases were studied. A retrospective study of five years was followed by five prospective years after the introduction of increased efforts to find previously neglected low-grade positive smears. Cervical cancer incidence, histology, stage, and early mortality were related to smear history.

The absence of cancer cases with neglected positive smears was a major reason for a 50 percent lower incidence of squamous cancers in the prospective period. Rapid onset interval cancers were few. Older women, never invited to the program, accounted for the majority of the advanced or aggressive cases in the former period. However, serious post-screening cancers remained common among women who had not had smears taken regularly up to the age of sixty, whereas there was little morbidity in women who had a regular smear to that age.

This organized screening program is a versatile tool in identifying women at risk. To attain effectiveness it needs, however, active monitoring of the smear history and a mechanism to ascertain that all women have participated well beyond the age of fifty before being left out of the program.