This study assesses the performance of the AutoPap® 300 QC System in identifying false‐negative (FN) smears in a slide population previously screened as normal and compares the detection rate to that achieved with a random rescreen of the same slide population. A total of 1,840 “normal” smears were rescreened both manually and by the AutoPap® 300 QC System. Overall, a total of 7 FN slides were detected. At QC selection rates of 30% and 20% the device achieved sensitivities for detection of FN smears of 57.19% (4/7) and 42.8% (3/7), respectively. This represents a three‐ to fourfold enrichment in the number of FN smears over that obtained by a random rescreen of a similar proportion of cases. None of the FN slides were identified by either method at a 10% rescreening rate. The ability of the device to detect slides previously classified as abnormal (n = 139) and FN (n = 40) was also studied. The overall sensitivity to abnormal smears at QC selection rates of 10%, 20%, and 50% was 61.9%, 77.0%, and 94.2%, respectively. Improved sensitivity to smears classified as LSIL or worse (n = 112) was obtained for corresponding selection rates (61.6%, 75.9%, and 93.8%). Sensitivity to FN slides classified as LSIL or worse (n = 17) for QC selection rates of 10%, 20%, and 50% was 29.4%, 70.6%, and 88.2%, respectively. The sensitivity and specificity of the device to an adequate squamous and endocervical cell component was also determined. At predetermined thresholds, the overall sensitivity to slides with an inadequate squamous cell component (n = 55) and to those smears with an endocervical cell component (n = 1,587) was 81.8%, and 82.7% respectively. The study demonstrated that the AutoPap® 300 QC System is superior to human random rescreen for the identification of FN smears although only a marginal improvement was noted due to the small sample. Further studies are required using a larger number of smears to fully assess the value of the device in quality control mode. The device also has the potential to improve the accuracy of specimen adequacy determinations and to serve as a useful adjunct to existing quality control measures designed to monitor individual performance and reporting accuracy. Diagn. Cytopathol. 16:505–512, 1997. © 1997 Wiley‐Liss, Inc.

The aim of the study was to assess the ability of the CytoRich® System to prepare optimal gynaecological smears for diagnosis. The diagnostic results obtained from evaluating 1,325 matched slide‐pairs, prepared using conventional methods and thin‐layer technology, were compared. Cytological material for study was obtained using the combined spatula–cytobrush sampling technique. An assessment of the pitfalls associated with the interpretation of these smears was also undertaken. Diagnostic agreement was achieved in 1,272 of the 1,325 matched slide‐pairs (96.0%), and these included 1,172 negative, 50 atypical, 24 low‐grade squamous intraepithelial lesion (LSIL), 24 high‐grade SIL (HSIL), and two malignancies. A total of 1,309 cases showed the same diagnosis within one diagnostic grade for an agreement of 98.8%. Evaluation of the 53 discordant diagnoses revealed that the conventional smear identified a significantly greater number of abnormal smears than the CytoRich technique (P < .001). It is suspected that the use of the combined spatula–cytobrush sampling technique did not provide adequate residual specimen for CytoRich after conventional smear preparation. This limitation is evidenced by the fact that the CytoRich preparations showed a lower yield of endocervical cells (P < .001) and infectious organisms (P < .001) than was demonstrated on conventional smears. Despite a number of diagnostic pitfalls associated with the interpretation of thin‐layer smears, these preparations were easier and faster to screen and showed well‐preserved and evenly distributed cells. Thin‐layer smears were also characterised by a marked reduction in thick cell groups, air drying artifact, and obscuring inflammation and blood. The results confirm the limitation of the combined spatula–cytobrush technique in these types of comparative studies. Diagn. Cytopathol. 1998;18:236–242. © 1998 Wiley‐Liss, Inc.

Location-guided screening is a feature of the AutoPap primary screening software. Areas of the smear most likely to contain an abnormality are identified for prompt review by the cytotechnologist, thereby facilitating diagnostic accuracy and reducing laboratory workload. A two-armed retrospective study comprising 6,000 conventional smears was undertaken to compare this approach with the current practice of full manual screening of conventional smears. Discrepant diagnoses between the two study arms were subject to an internal discrepancy review process to determine the final truth diagnosis. Analysis of the results show that AutoPap location-guided screening is at least equivalent to current practice when detecting high-grade or suspected high-grade smears. However, the device does not detect low-grade abnormalities, unsatisfactory smears, an endocervical component or organisms, as well as standard screening. The device also assigns a numerical score to each slide, with abnormal smears allocated a higher rank. Slide ranking was found to be of value in triaging abnormal smears for prompt screening and reporting. The performance of the primary screening software was found to be comparable to previous studies, with the majority of abnormal smears being selected by the instrument for manual review.