Clinical performance of primary HPV screening cut‐off for colposcopy referrals in HPV‐vaccinated cohort: Observational study

OBJECTIVE: To understand the effect of changing from cytology‐based to primary HPV screening on the positive predictive value (PPV) of colposcopy referrals for cervical intraepithelial neoplasia (CIN) in a cohort offered HPV vaccination. DESIGN: Retrospective pre/post observational cohort study. SETTING: Scotland. POPULATION OR SAMPLE: 2193 women referred to colposcopy between September 2019 and February 2020 from cytology‐based screening and between September 2020 and February 2021 from primary high‐risk HPV (hrHPV) screening. METHODS: Calculating positive predictive values (PPVs) for two cohorts of women; one having liquid‐based cytology screening and the other, the subsequent hrHPV cervical screening as a pre/post observational study. MAIN OUTCOME MEASURES: Positive predictive values of LBC and hrHPV cut‐offs for colposcopy referral for CIN at colposcopy. RESULTS: Three papers fitted our criteria; these reported results only for cytology‐based screening. The PPV was lower for women in HPV‐vaccinated cohorts indicating a lower prevalence of disease. Vaccination under the age of 17 had the lowest PPV reported. Scottish colposcopy data concerning hrHPV and cytology showed a non‐significant difference between PPV (17.5%, 95% CI 14.3–20.7, and 20.6, 95% CI 16.7–24.5, respectively) for referrals with a cut‐off of low grade dyskaryosis (LGD); both met the standard set of 8–25%. The hrHPV PPV (66.7, 95% CI 56.8–76.6) was comparable to cytology (64.1, 95% CI 55.8–72.4) for referrals with a cut‐off of high grade dyskaryosis (HGD) but neither met the standard set of 77–92%. CONCLUSIONS: Current literature only provides PPVs for LBC and, overall, the vaccinated cohort had lower PPVs. Only LG dyskaryosis met PHE criteria. The PPV for HPV‐vaccinated women undergoing either LBC or HR‐HPV screening were not statistically different. However, similar to papers in the current literature, HG dyskaryosis (HGD) PPVs of both techniques did not meet the PHE threshold of 76.6–91.6% outlined in the cervical standards data report.