Hologic ThinPrep Imager Duo Operator's Manual page 8

G. PERFORMANCE CHARACTERISTICS
A multi-center, two-armed clinical study was performed over an eleven (11) month period at four
(4) cytology laboratory sites within the United States. The objective of the study entitled "Multi-
Center Trial Evaluating the Primary Screening Capability of the ThinPrep
to show that routine screening of ThinPrep Pap Test slides using the ThinPrep Imaging System is
equivalent to a manual review of ThinPrep slides for all categories used for cytologic diagnosis
(specimen adequacy and descriptive diagnosis) as defined by the Bethesda System criteria
The two-arm study approach allowed a comparison of the cytologic interpretation (descriptive
diagnosis and specimen adequacy) from a single ThinPrep prepared slide, screened first using
standard laboratory cervical cytology practices (Manual Review) and then after a 48 day time lag
were screened with the assistance of the ThinPrep Imaging System (Imager Review). A subset of
slides from the study were reviewed and adjudicated by a panel of three (3) independent
Cytopathologists to determine a consensus diagnosis. The consensus diagnosis was used as a "gold
standard" for truth to evaluate the results of the study.
G.1 LABORATORY AND PATIENT CHARACTERISTICS
Of the 10,359 subjects in the study, 9,550 met the requirements for inclusion in the descriptive
diagnosis analysis. During the study, 7.1% (732/10,359) slides could not be read on the Imager and
required a manual review during the Imager Review arm. Excessive number of air bubbles on the
slides was the leading contributor. Additional factors included focus problems, slide density, slide
identification read failures, slides detected out of position, multiple slides seated within a cassette
slot and slides that had already been imaged. The cytology laboratories participating in the study
were comprised of four centers. All sites selected had extensive experience in the processing and
evaluation of gynecologic ThinPrep slides, and were trained in the use of the ThinPrep Imaging
System. The study population represented diverse geographic regions and subject populations of
women who would undergo cervical screening with the ThinPrep Imaging System in normal clinical
use. These sites included both women being routinely screened (screening population) and patients
with a recent previous cervical abnormality (referral population). The characteristics of the study
sites are summarized in Table 1.
Table 1: Site Characteristics
Number of Cytotechnologists in Study
Number of Cytopathologists in Study
Site
Low Risk Population
High Risk Population
HSIL+ prevalence
ThinPrep Pap Tests Per Year
Number of Cytotechnologists
Number of Cytopathologists
®
1 2 3
88% 82% 90%
12% 18% 10%
1.1% 0.7% 0.4%
120,000 70,200 280,000
14 9 32
2 2 2
6 5 6
1 2 1
Imaging System" was
2 .
4
94%
6%
0.6%
105,000
11
2
14
2
MAN-08723-001 Rev. 001 page 4 of 28