Comparison of the performance of rapid prescreening, 10% random review, and clinical risk criteria as methods of internal quality control in cervical cytopathology.
BACKGROUND
Rapid prescreening (RPS) is an internal quality-control (IQC) method that is used both to reduce errors in the laboratory and to measure the sensitivity of routine screening (RS). Little direct comparison data are available comparing RPS with other more widely used IQC methods.


METHODS
The authors compared the performance of RPS, 10% random review of negative smears (R-10%), and directed rescreening of negative smears based on clinical risk criteria (RCRC) over 1 year in a community clinic setting.


RESULTS
In total, 6,135 smears were evaluated. The sensitivity of RS alone was 71.3%. RPS detected significantly more (132 cases) false-negative (FN) cases than either R-10% (7 cases) or RCRC (32 cases). RPS significantly improved the overall sensitivity of the laboratory (71.3-92.2%; P = .001); neither R-10% nor RCRC significantly changed the sensitivity of RS. RPS was not as specific as the other methods, although nearly 68% of all abnormalities detected by RPS were verified as real. RPS of 100% of smears required the same amount of time as RCRC but required twice as much time as R-10%.


CONCLUSIONS
The current results demonstrated that RPS is a much more effective IQC method than either R-10% or RCRC. RPS detects significantly more errors and can improve the overall sensitivity of a laboratory with either a modest increase or no increase in overall time spent on IQC. R-10% is an insensitive IQC method, and neither R-10% nor RCRC can significantly improve the overall sensitivity of a laboratory.
Tavares
Suelene B N
SB
School of Pharmacy, Federal University of Goias, Goiania, Goias, Brazil.
Alves de Sousa
Nadja L
NL
Manrique
Edna J C
EJ
Pinheiro de Albuquerque
Zair B
ZB
Zeferino
Luiz C
LC
Amaral
Rita G
RG
D003584:Cytological Techniques / Q000592:standards*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D011786:Quality Control; D011897:Random Allocation; D012680:Sensitivity and Specificity; D014626:Vaginal Smears / Q000592:standards*