Interobserver variability of cervical cytology in HIV-infected women

Our objectives were to determine the reproducibility of cytological specimen interpretation between two pathologists in human immunodeficiency virus (HIV)-infected women (from the VIHGY, ANRS CO17 study of human papillomavirus genital pathology among HIV-positive women) and to analyse the improvement, if any, between conventional and liquid-based cytology (LBC) interpretations.

A sample of all abnormal and 40% of randomly selected normal Papanicolaou (Pap) tests was randomly ordered and read blindly by a second pathologist using the revised Bethesda terminology 2001. For both conventional and liquid-based preparations, unweighted and Cicchetti-Allison-weighted kappa and their 95% confidence intervals (CIs) were calculated. Kappa values were then compared using the Altman rule to classify the reproducibility of cytological specimen interpretation.

Two hundred and seventy-seven conventional Pap tests were reviewed, including 79 abnormal and 10 unsatisfactory results. Overall agreement between the two observers was 78%, with an estimated Cicchetti-Allison-weighted kappa of 0.69 (95%CI, 0.61-0.77). The corresponding values for the 268 LBCs, including 123 abnormal and two unsatisfactory results, were 84% and 0.82 (95%CI, 0.76-0.87), respectively. The reproducibility of LBC interpretations was significantly higher than that of conventional preparations (P = 0.009) and, for both laboratories, the percentages of unsatisfactory results were significantly lower for LBC.

In HIV-infected women in the combination antiretroviral therapy era, the strength of agreement was better for LBCs than for conventional preparations, with a lower percentage of unsatisfactory results. When available, LBC should be preferred because of its higher reproducibility.