Determining the utility and effectiveness of the NeoPath AutoPap 300 QC system used routinely

OBJECTIVE: To evaluate routine use of the NeoPath AutoPap 300 QC System (AP 300) as it influences diagnostic quality and operations in a large cytolog y laboratory. STUDY DESIGN: During a three-month period, 35,143 conventionally prepared c onsecutive cervical cytologic smears taken from non-high-risk women and eva luated as negative by our staff of 25 cytotechnologists were selected for p rocessing by four AP 300 instruments. Slides flagged for review by the AP 3 00 were reevaluated by our five quality control (RC) cytotechnologists. Fal se negative (FN) results were compared with results of our current practice (CP), random-selection QC method, used during the preceding six months. RESULTS: A 240% increase was seen in the FN detection rate for atypical squ amous cells of undetermined significance (ASCUS) and squamous intraepitheli al lesions (SIL) (n AP = 65 FN in 5,034 QC, n CP = 77 FN in 22,052 QC) and a 744% increase in the FN detection rate for low and high grade SIL (n AP = 24 FN/5,034 QC, n CP = 12 FN/22,052 RC). The rate of overcall by cytotechn ologists did not increase. The QC ASCUS/SIL ratio improved. FN biopsy corre lation increased from 45% to 85% (n CP = 17/38 agreement, n AP = 23/27 agre ement). Turnaround time increased by one or more days for negative and 1.5 days for QC result reporting. Sensitivity varied among instruments. CONCLUSION: More FN results and greater specificity were seen using the AP 300 than using CP. As with other instrumentation, each laboratory should es tablish acceptable ranges of performance and baseline values for sensitivit y and specificity.