Variation in the assessment of adequacy in cervical smears

Objective: To assess the interobserver reproducibility of the diagnosis of 'adequacy' of cervical smears according to the Bethesda System criteria in cervical smears. Study design: 358 cervical smears were obtained from three Italian cytopathological centres in 1998-99. All centres provided consecutively collected smears. The cervical smears were independently and blindly assessed by four cytologists. The screening was performed using a 10x objective and an additional evaluation of the percentage of cellularity was performed using a 4x objective. Results: The proportion of smears assessed by the four cytologists as 'adequate' ranged from 60% to 70%, the proportion of 'satisfactory for evaluation but limited by' ranged from 27% to 38%, and the proportion of 'inadequate smears' ranged from 2% to 4%. Full agreement in the assessment of smear adequacy was observed in 311 slides and disagreement was observed only in 47. The category 'inadequate smear' was less reliable than the other two; however, the kappa value observed was acceptable. Conclusion: The present study shows that it is possible to achieve a high reproducibility in the assessment of smear adequacy, at least among expert cytologists who follow the Bethesda System criteria strictly.