Systematic reviews and meta-analyses of the accuracy of HPV tests, visual inspection with acetic acid, cytology, and colposcopy

Background Cervical cancer screening is offered to women to identify and treat cervical intraepithelial neoplasia (CIN). Objectives To support WHO guidelines, a systematic review was performed to compare test accuracy of the HPV test, cytology (cervical smear), and unaided visual inspection with acetic acid (VIA); and to determine test accuracy of HPV and colposcopy impression. Search strategy Medline and Embase were searched up to September 2012, and experts were contacted for references. Selection criteria Studies of at least 100 nonpregnant women (aged ≥ 18 years) not previously diagnosed with CIN were included. Data collection and analysis Two investigators independently screened and collected data. Pooled sensitivity and specificity, and absolute differences were calculated, and the quality of evidence assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation). Main results High to moderate quality evidence was found. The greatest difference in overtreatment occurred with VIA instead of the cervical smear (58 more per 1000 women). Differences in missed treatment ranged from 2-5 per 1000 women. For 1000 women screened positive and then sent to colposcopy, 464 would be falsely diagnosed with CIN grade 2-3 and treated. Conclusions Although differences in sensitivity between tests could be interpreted as large, absolute differences in missed diagnoses were small. By contrast, small differences in specificity resulted in fairly large absolute differences in overtreatment.