Rapid (partial) prescreening of cervical smears: the quality control method of choice?

Abstract

Rapid rescreening of all negative and inadequate smears is the quality control method of choice in the UK. The sensitivity of primary screening of laboratory and individual screeners are major indicators of screening quality and are dependent on the number of false negative smears found by rapid screening for their calculation. High sensitivity may indicate good quality primary screening or poor quality rapid review. Quantifiably high quality rapid rescreening is essential if these sensitivity figures are to be meaningful. A 12-month study was undertaken in routine practice using the prescreening mode to ascertain the sensitivity of rapid (partial) screening in our department. The final results of smears were compared with those of rapid prescreening. The calculated sensitivity ranged from 92-54% for high-grade abnormalities and 75-33% for all grades, revealing a wide range of performance between individual prescreeners. Rapid prescreening can identify individuals best suited to rapid screening in routine practice. By using these prescreeners only, the sensitivity of cervical screening could be raised. Rapid (partial) prescreening should be considered as the quality control method of choice.

Rapid prescreening of papanicolaou smears

“…As in previous studies in the literature, [22][23][24][25]29,31,32 our experience with RPS shows that it is an efficient and practical QC strategy in gynecologic cytology because it provides a measurable parameter with which to monitor the sensitivity of the Pap smears and allows for timely corrections before releasing the results to the clinicians.…”

“…It has since been shown to be an efficient tool for QC in gynecologic cytology. [22][23][24][25][26] It is also reported to be as sensitive as RR in detecting abnormal smears. 33 Because all cases subsequently undergo routine full screening, it is possible to calculate the sensitivity of the prescreening procedure and, taking additional cases picked up on RPS into account, to better estimate the FNR for a laboratory.…”

“…This issue is addressed through a variation of RR called rapid prescreening (RPS) that involves rapid screening of all Pap smears before their full screening. [23][24][25][26] The aim of the current study was to attempt to improve the sensitivity of Pap smears through a better QC measure. Specifically, we describe our experience with the implementation of RPS as a QC measure in a large cytopathology laboratory in Canada.…”

Improvement in the routine screening of cervical smears

“…3,15,19 Nevertheless, one of the criticisms of the technique is that it permits only partial evaluation of the rapid reviewer's performance because only smears defined as negative in routine screening are revised; therefore, it is impossible for 100% rapid review to detect any abnormal cases that were not identified at routine screening. 20,21 Rapid prescreening permits the sensitivity not only of routine screening but also of rapid prescreening itself to be calculated. This is possible because all prescreened smears will be evaluated later at routine screening.…”

“…As shown in various studies, it is possible to use abnormal cases identified both by rapid prescreening and by routine screening to monitor the performance of professionals in the daily routine of cytology laboratories. 6,9,20,[22][23][24][25] Nonetheless, it is only in Canada and the United Kingdom that this method is being routinely used. 4,25,26 Finally, the high rates of false-negatives constitute one of the principal problems faced by cytology laboratories.…”