Specimen adequacy of ThinPrep sample preparations in a direct-to-vial study

OBJECTIVE: To assess specimen adequacy of the ThinPrep slide preparation method in routine use. STUDY DESIGN: Two studies, a feasibility study of 299 women and a clinical study of 499 women, were conducted. A broom-type collection device was used and rinsed directly into PreservCyt vials. Slides were prepared with the ThinPrep 2000 device, screened and classified according to the Bethesda System. The proportion of ThinPrep slides described as ''Satisfactory But Limited By: No Endocervical Component (SBLB:No ECC)'' was then compared to the proportion of SBLB: No ECC slides found on conventional smears in a previously conducted clinical trial of over 7,000 patients. RESULTS: For the feasibility study the proportion of ThinPrep slides described as SBLB: No ECC was 9.36% as compared to the clinical trial combined rate of 9.4% for conventional smears. For the clinical study, 4.96% of ThinPrep slides were SBLB:No ECC as compared to the 4.4% SBLB:No ECC rate for conventional smears from the same clinical trial. The proportions were statistically equivalent for both studies. CONCLUSION: It is expected that the rate of representing endocervical component will be maintained when the ThinPrep preparation method is used routinely in place of the conventional cytologic smear method.