August 2010

Roger B. Lane Jr., MD

The CAP assesses laboratory practice patterns with questionnaires sent to participants in CAP educational programs. Results of these surveys have become the basis for the benchmarks in the CAP Laboratory Accreditation Program. A new study by Galen Eversole, MD, et al., examines the data from the 2006 supplementary questionnaire sent to all laboratories participating in the Interlaboratory Comparison Program in Cervicovaginal Cytology (Practices of participants in the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology, 2006. Arch Pathol Lab Med. 2010;134:331–335).

The study by Eversole, et al., compares data from the 2006 supplementary questionnaire with data from the 2003 supplementary questionnaire. During the period between the two surveys several changes in cervicovaginal cytology screening occurred, including widespread implementation of the 2001 Bethesda System, widespread use of liquid-based preparations, the introduction of image-based and automated-screening technologies, and the establishment of human papillomavirus testing in conjunction with a Papanicolaou test in women older than 30 years and as a triage test for atypical squamous cells of undetermined significance (ASC-US) in women older than 20 years.

Results from the survey showed widespread implementation of the 2001 Bethesda System (used by more than 97 percent of reporting laboratories). Twenty-eight percent of reporting laboratories modified 2001 Bethesda System terminology to include the “low-grade squamous intraepithelial lesion cannot exclude higher-grade lesion” category. Two-thirds of reporting laboratories use educational notes routinely in their reports, possibly reflecting the CAP Laboratory Accreditation Program criterion (CYP.07582) that laboratories educate providers about the Pap test—that it is a screening test with inherent false-negative results. The authors discuss other acceptable ways of satisfying this educational criterion.

Interestingly, results from the survey showed an increased rate of detection of low-grade squamous intraepithelial lesions (LSIL) in 2006 versus 2003 (2.6 percent versus 2.1 percent), with the increased rate confined to liquid-based preparations. LSIL and ASC-US rates were significantly higher in liquid-based preparations compared with conventional smears. Overall rates for high-grade squamous intraepithelial lesions (median, 0.5 percent) and atypical squamous cells (median, 4.3 percent) changed little between the two surveys. The median ratio of atypical squamous cells to squa-mous intraepithelial lesions and carcinomas for all specimen types combined in 2006 was 1.5, similar to the 2003 median ratio of 1.4. The study examines these statistics and many others in detail.

The study includes an excellent discussion of the use of the ratio of atypical squamous cells to squamous intraepithelial lesions as a quality improvement monitor, including a discussion of why this ratio may vary among laboratories. In addition, the authors report how the latest survey results are incorporated into the CAP Laboratory Accreditation Program checklist. This study by Eversole, et al., highlights how CAP questionnaires can be used to provide valuable benchmarking data for laboratory use in quality assurance practices and is recommended reading for everyone involved in cervico-vaginal cytology screening.