INTRALABORATORY REPRODUCIBILITY OF CERVICAL CYTOLOGY DIAGNOSES IN THEEXTERNAL QUALITY ASSURANCE SCHEME OF THE EMILIA-ROMAGNA REGION OF ITALY

In an external quality assurance (EQA) scheme, 110 selected cervical s mears were independently reported by seven cytology laboratories using the 1988 Bethesda System, In one of these, a random sample of 60 stud y smears was independently classified by five cytologists before under going joint examination according to EQA protocol, Internal agreement (i.e., among these cytologists) was compared with external agreement ( between these cytologists and the other six laboratories) and with int erlaboratory agreement (among these laboratories). The kappa value for internal agreement on sample adequacy (0.57) was considerably greater than those for external (0.16) and interlaboratory agreement (0.10). For interpretation of epithelial abnormalities, internal kappa was exc ellent (0.80) but not substantially greater compared with external kap pa (0.66) and interlaboratory kappa (0.70), Calculation of class-speci fic kappa values revealed (a) that superiority of internal agreement o n sample adequacy was restricted to the notations of ''less than optim al'' and of ''satisfactory,'' and (b) that internal increase in agreem ent on cytologic abnormalities was substantial for the diagnosis of '' atypical cells of undetermined significance.'' (C) 1996 Academic Press , Inc.