Cervical cytology reading times: a comparison between ThinPrep Imager and conventional methods.

We aimed to compare the times cytologists spend reviewing cervical cytology slides processed by the ThinPrep Imager (TPI) with times they spend examining conventional cytology (CC) slides. We also aimed to examine the effect of cytologists' experience on reading times. Using a cross-sectional analytical design, we analyzed routine laboratory data, collected retrospectively over 7 months, for 41 cytologists, including paired data for 20 who read both TPI and CC slides. For the 20 cytologists who read both types of cytology, the mean reading rate was 13.3 slides per hour for TPI slides and 6.1 slides per hour for CC slides. The mean within-reader difference between TPI and CC rates was 7.2 slides per hour (P < 0.001). For CC reading, mean times did not differ between those who were additionally trained to read TPI slides and those who only read CC. Slower readers had greater increases in speed when using the TPI compared with CC reading than did faster readers (P < 0.001). More experienced cytologists tended to read CC slides more quickly than did those less experienced, but experience did not affect TPI reading times or within-reader differences in reading times between cytology types. The TPI significantly reduced reading times compared with CC. This reduction was greater amongst slower readers, and was unrelated to experience.

Accuracy of reading liquid based cytology slides using the ThinPrep Imager compared with conventional cytology: prospective study.

OBJECTIVE: To compare the accuracy of liquid based cytology using the computerised ThinPrep Imager with that of manually read conventional cytology. DESIGN: Prospective study. SETTING: Pathology laboratory in Sydney, Australia. PARTICIPANTS: 55,164 split sample pairs (liquid based sample collected after conventional sample from one collection) from consecutive samples of women choosing both types of cytology and whose specimens were examined between August 2004 and June 2005. MAIN OUTCOME MEASURES: Primary outcome was accuracy of slides for detecting squamous lesions. Secondary outcomes were rate of unsatisfactory slides, distribution of squamous cytological classifications, and accuracy of detecting glandular lesions. RESULTS: Fewer unsatisfactory slides were found for imager read cytology than for conventional cytology (1.8% v 3.1%; P<0.001). More slides were classified as abnormal by imager read cytology (7.4% v 6.0% overall and 2.8% v 2.2% for cervical intraepithelial neoplasia of grade 1 or higher). Among 550 patients in whom imager read cytology was cervical intraepithelial neoplasia grade 1 or higher and conventional cytology was less severe than grade 1, 133 of 380 biopsy samples taken were high grade histology. Among 294 patients in whom imager read cytology was less severe than cervical intraepithelial neoplasia grade 1 and conventional cytology was grade 1 or higher, 62 of 210 biopsy samples taken were high grade histology. Imager read cytology therefore detected 71 more cases of high grade histology than did conventional cytology, resulting from 170 more biopsies. Similar results were found when one pathologist reread the slides, masked to cytology results. CONCLUSION: The ThinPrep Imager detects 1.29 more cases of histological high grade squamous disease per 1000 women screened than conventional cytology, with cervical intraepithelial neoplasia grade 1 as the threshold for referral to colposcopy. More imager read slides than conventional slides were satisfactory for examination and more contained low grade cytological abnormalities.