Clinical determinants of a positive visual inspection after treatment with acetic acid for cervical cancer screening

Objective To examine the determinants of a positive visual inspection after acetic acid (VIA), including the relationship of testing positive for high-risk human papillomavirus (HR-HPV), which is the necessary cause of cervical cancer. Design A prospective cohort study. Setting Three clinical sites in rural China. Population A total of 7541 women aged 25–65 years. Methods All women underwent VIA, DNA testing, by two DNA tests performed on both clinician- and self-collected specimens, and HPV E6 oncoprotein testing. Those positive by any test underwent colposcopy and four-quadrant biopsy evaluation. A random sample of women with negative screening results also underwent colposcopy and, if colposcopic abnormalities were observed, four-quadrant biopsy evaluation was performed. Women diagnosed with cervical intraepithelial neoplasia grade 2 (CIN2), or more severe grades (CIN2 + ), underwent treatment. Main outcome measure Testing positive for VIA. Results Overall, 7.6% (95% confidence interval, 95% CI, 7.0–8.2%) had a positive VIA. Women who tested positive for HPV were more likely to have a positive VIA than women who tested negative for HPV (15.0%, 95% CI 12.9–17.2% versus 6.3%, 95% CI 5.7–6.9%; P < 0.001). Older women were less likely to have a positive VIA (Ptrend < 0.001), including women with CIN2 +  (Ptrend < 0.001). A logistic regression model demonstrated that diagnosis (CIN2 +  versus colposcopic impression versus women with CIN2 +  regardless of colposcopic impression (71.4 versus 47.2%). Conclusions The age of the population and method of disease ascertainment should be considered in the interpretation of any VIA performance.