THE FALSE-NEGATIVE FRACTION FOR PAPANICOLAOU SMEARS - HOW OFTEN ARE ABNORMAL SMEARS NOT DETECTED BY A STANDARD SCREENING CYTOLOGIST

Screening error rates have been measured in various ways. The false-ne gative fraction is advantageous because it is valid for comparisons be tween laboratories, which is crucial if standards for error rates are to be developed. False-negative fractions reported or calculated from data in the literature range from approximately 2% to 28%. Some of the highest published rates have come from prestigious academic laborator ies. The lowest rates are from studies that covered terms of a year or less and in which only small parts of each slide were rescreened or t he rescreeners were relatively inexperienced. Before standards for fal se-negative fractions can be set, we must collect more data and encour age more laboratories to measure the false-negative fraction.