IMPROVING ACCURACY IN GYNECOLOGIC CYTOLOGY - RESULTS OF THE COLLEGE-OF-AMERICAN-PATHOLOGISTS INTERLABORATORY COMPARISON PROGRAM IN CERVICOVAGINAL CYTOLOGY

The College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology (PAP) is a quarterly mailed glass-slide quality improvement program. This growing program started as a pilot in 1989 with 207 laboratories. In 1991, 605 laboratories participated. The diagnostic menu is modified from the Bethesda System and divides referenced slides into a negative series (normal, infectious, and reactive) and a positive series of epithelial lesions. A facsimile option facilitates immediate educational feedback. The 1989 through 1991 major discrepancy rate averaged 5%. The consensus laboratory response had higher concordance than either pathologist or cytotechnologist responses. Low-grade squamous intraepithelial lesion was the leading cause of false-negative participant response, while reactive/reparative change was the leading cause of false-positive response. Pathologist false-negative and false-positive responses from group or large case-volume practices were significantly lower than those from solo or small case-volume practices. Cytotechnologists in multiple-technologist or large-volume laboratories had significantly lower false-negative responses than solo technologists or those in low case-volume laboratories, but false-positive rates did not differ. Experienced participants had fewer major discrepancies. The interlaboratory Comparison Program in Cervicovaginal Cytology illustrates the feasibility of a large, mailed glass-slide program, and offers laboratories a continuous method for monitoring and improving performance in gynecologic cytology.