Rapid screening of cervical smears as a method of internal quality control. For how long should we rescreen?
OBJECTIVE
To compare the effectiveness of rapid screening of cervical smears as a method of internal quality control with 10% random rescreening.


METHODS
From June 5 to July 14, 1995 (6 weeks), all consecutive cervical smears received in the department (n = 8,800) were entered into the study and were prescreened for a duration of 30 seconds (n = 2,938), 1 minute (n = 2,925) or 2 minutes (n = 2,937) over a period of 2 weeks each.


RESULTS
Rapid screening of all negative and unsatisfactory smears detected more cytologic abnormalities than would be expected with 10% random rescreening. Thirty-second rapid screening of all negative and unsatisfactory smears was more efficient in detecting false negatives than screening a proportion of the smears for longer periods of time. Rapid screening was also a very effective method of detecting severe cytologic abnormalities in unscreened smears, detecting over 90% of high grade lesions.


CONCLUSIONS
Rapid rescreening of negative and unsatisfactory cervical smears is recommended as a very effective method of internal quality control. It is superior to 10% random rescreening in reducing the false negative rate. Thirty-second rapid rescreening is the most efficient period for which smears should be screened. Rapid screening of unscreened smears could be used as a means of selecting patients for prompt referral when a laboratory backlog exists.
Farrell
D J
DJ
Department of Clinical Cytology, Newcastle General Hospital, Newcastle upon Tyne, England, U.K.
Bilkhu
S
S
Gibson
L M
LM
Cummings
L
L
Wadehra
V
V
D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000592:standards*; D011786:Quality Control; D012680:Sensitivity and Specificity; D002577:Uterine Cervical Diseases / Q000175:diagnosis / Q000473:pathology / Q000517:prevention & control*; D014626:Vaginal Smears / Q000592:standards*