Validity and reproducibility of cytologic diagnosis in a sample of cervical cancer screening centers in Mexico.
OBJECTIVE
To evaluate the diagnostic precision of the cervical cytology (smear) in a sample of 16 cervical cancer screening centers (CCSCs) from the Mexican Ministry of Health and Mexican Institute for Social Security CCSCs distributed across the country.


METHODS
Each center received a batch of 90 cytologic specimens with a random positive prevalence of 1.5-36%. Positive cases were always histologically confirmed. The "gold standard" was an expert pathologist certified by the Mexican Board of Pathology.


RESULTS
Our results show that cytologic diagnosis validity and reproducibility vary greatly within and between institutions. The false negative rate (FNR) varied between 10% and 54%, independent of the prevalence of positive cases.


CONCLUSIONS
Quality control of diagnostic precision is central to the consistency of results obtained at CCSCs. In Mexico the high FNR calls for governmental regulation of cytopathology policies and methods, such as through national and international accreditation of cytotechnology programs. In order to decrease the FNR, developing countries must frame managerial development strategies to streamline the cervical cancer screening program, including continuing education, improvement of operation processes in CCSCs, internal and external quality control of cytopathology laboratories and cervical sampling procedures, and standardization of diagnostic criteria.
Lazcano-Ponce
E C
EC
Center for Population Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
Alonso de Ruíz
P
P
López-Carrillo
L
L
Nájera-Aguilar
P
P
Avila-Ceniceros
R
R
Escandón-Romero
C
C
Cisneros
M T
MT
Hernández-Avila
M
M
D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000592:standards*; D008800:Mexico / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000517:prevention & control; D014626:Vaginal Smears / Q000592:standards*