Detection of laboratory false negative smears by the PAPNET cytologic screening system.

OBJECTIVE: To evaluate the ability of PAPNET-assisted screening to identify abnormal slides that had originally been reported as negative on manual screening.

STUDY DESIGN: One hundred ninety-five abnormal slides were seeded into 20,000 slides that had been assessed as showing no abnormality on two occasions by manual screening. All slides were submitted for PAPNET review and the tiles assessed by trained cytotechnologists.

RESULTS: With a single assessment of the PAPNET tiles and when the prevalence of seeded abnormality was around 1%, only 44% of the seeded abnormal slides were recognized as abnormal. With multiple independent assessments and by increasing the prevalence of abnormality to 81%, 83% of the seeded abnormalities were recognized by at least one of three reviewing cytotechnologists. This increase in sensitivity appeared to be associated with a state of relative hyperalertness in the reviewing cytotechnologists.

CONCLUSION: The sensitivity of a PAPNET-assisted review was < 100% for the detection of seeded abnormal slides. Altering the format of presentation of information to the cytotechnologist may result in improved sensitivity.