ADEQUACY OF SCREENING CERVICAL CYTOLOGY AMONG HUMAN IMMUNODEFICIENCY VIRUS-SEROPOSITIVE WOMEN

Objective. To evaluate the adequacy of cytology in detecting cervical intraepithelial neoplasia (CIN) among human immunodeficiency virus (HI V)-seropositive women compared to controls. Methods. A cross-sectional study was carried out evaluating 241 HIV-seropositive women and 991 c ontrols (404 HIV seronegative and 587 of unknown HIV status) at risk f or CIN attending a vaginitis clinic. All patients had a Pap smear and a standard colposcopic examination of the lower genital tract. Cervica l biopsies were taken as indicated by colposcopy. Cytology and histolo gy slides were read by a cytopathologist blinded to patients' serostat us, False-negative cytologic cases were reviewed by three independent cytopathologists to estimate sampling and screening error rates. Sensi tivity, specificity, and false-negative rate of cytologic smears were compared between HIV seropositives and controls. We estimated the samp ling and screening error rates among cases with false-negative cytolog y. Results. Among seropositives, the sensitivity, specificity, and the false-negative smear rate for CIN were 73.4% (47/64), 97.1% (134/138) , and 26.6% (17/64), respectively. The corresponding figures in contro ls were 83.8% (83/99), 99.04% (825/833), and 16.2% (16/99), respective ly, and did not differ significantly from those of seropositives. The negative predictive value of cytology was lower among seropositives (1 34/151) than in controls (825/841, chi(2) = 34.8, P < .001). The agree ment between cytologic readings and combined colposcopy and histology was stronger among controls (kappa = 0.789, 95% CI 0.723 to 0.856) tha n among seropositives (kappa = 0.593, 95% CI 0.475 to 0.712). Three in dependent cytopathologists were unable to detect atypical cells in 52. 9% (9/17) of false-negative smears taken from seropositive women as op posed to 37.5% (6/16) of controls. Conclusions. The sensitivity, speci ficity, and false negative rate of screening cytology for CIN among HI V seropositive women are comparable with those in the general populati on. Since almost 50% of false-negative results could be attributed to sampling errors, more frequent cytological screening may prove to be b eneficial to this high-risk group. (C) 1998 Academic Press.