It has been suggested that adjustment for incomplete compliance with follow-up in women with positive human papillomavirus (HPV) tests would be appropriate for estimating the true sensitivity of cervical screening with HPV testing. We assessed the compliance and its impact on CIN3 detection in all eight randomised controlled trials (RCT) with published baseline-round data.
We extracted data on recommended follow-up procedures, follow-up compliance, and CIN3 detection for both arms of each RCT, and assessed their correlation.
Compliance with a direct referral for colposcopy was around 90% in all RCTs, whereas compliance with repeated testing among HPV-positive/cytology-negative women was around 60% in three RCTs and 73% in one RCT. Detection of CIN3 was significantly increased in two out of six RCTs with reported data. The correlation between compliance with follow-up in HPV-positive women and relative CIN3 detection was 0.48 (P=0.33).
There is at present scant evidence to support the view that the measured sensitivity of HPV screening is a simple reflection of compliance with follow-up. Adjustment of measured cervical intraepithelial neoplasia detection on the basis of compliance data may not always be justifiable, and if adjustment is made, it should be used very judiciously.
Keywords: cervical cancer, screening, human papillomavirus, cytology, follow-up compliance, randomised controlled trial