Over a 10-year period the Pap program at our community hospital laboratory progressed from the use of 100% conventional smears to predominantly ThinPrep® (TP) and then to nearly 100% SurePath® (SP). During this period the annual Pap volume grew from less than 20,000 to nearly 50,000. This retrospective review focuses on improvements in high-grade squamous intraepithelial lesion (HSIL) detection rates and specimen adequacy rates during the 10-year period.
The laboratory database was used to identify 310,080 Pap test records between 1995 and 2004 inclusive. Pap type differences in HSIL detection rates and specimen adequacy rates were examined using the Cochran–Mantel–Haenszel test, with year as the stratification variable. The Breslow–Day test was used to evaluate the consistency of differences across the years. The overall results are summarized below in tabular format.
|Pap Method||Total Paps||Total % HSIL||Total % Unsat|
HSIL detection rates were significantly higher for liquid-based Pap tests compared with conventional smears (P < 0.0001). In addition, SP was associated with higher HSIL detection rates than TP with an estimated common odds ratio (OR) of 1.37 (95% confidence interval (CI), 1.10 − 1.71; P = 0.005), and higher specimen adequacy compared with TP or conventional Pap methods (P < 0.0001). Diagn. Cytopathol. 2007;35:148–153. © 2007 Wiley-Liss, Inc.