Comparison of monolayer specimens and conventional smears

INTRODUCTION: Monolayer specimens were compared with conventional smears in a split sample study. The quality of the specimens, sensitivity, time consumption, and costs were elucidated. METHOD: Conventional smears and fixated residual material from 1701 women were available. RESULTS: The number of inadequate/less adequate specimens was reduced significantly (p < 0.001). Diagnostic agreement was found in 1531 (90%) of the 1701 cases (kappa = 0.52, SE (kappa) = 0.026). Dysplasia (NOS) was diagnosed in seven monolayer specimens (0.4%) versus 33 smears (1.9%) and ratio atypia/low grade was reduced by 33%, which indicates greater accuracy in diagnosis in monolayers. Histological follow-up showed sensitivities of 95% (monolayers) and 94% (smears). The time consumed (laboratory work, screening) on a smear versus a monolayer specimen was 11.5 minutes versus 9.3 minutes. Utensil costs of a smear are kr. 10.69. compared to kr. 26.50 for a monolayer specimen. CONCLUSION: The higher costs should be set against the saving in significantly improved specimen quality, improved diagnostic accuracy, and shorter time consumption. The use of the monolayer technique (direct to vial) is recommended to replace the conventional smear.