BackgroundHigh-risk human papillomavirus (HPV) test is replacing cytology as the primary cervical cancer screening test due to superior sensitivity, but in most countries women ≥65 years have never had an HPV test despite they account for around 50% of cervical cancer deaths. We explored the effect of a catch-up HPV test among 65- to 69-year-old women without previous record of HPV-based screening.Methods and findingsThis population-based nonrandomized intervention study (quasi-experimental design) included Danish women aged 65 to 69 with no record of cervical cancer screening in the last ≥5.5 years and no HPV-exit test at age 60 to 64 at the time of study inclusion. Eligible women residing in the Central Denmark Region were invited for HPV screening either by attending clinician-based sampling or requesting a vaginal self-sampling kit (intervention group,n= 11,192). Women residing in the remaining four Danish regions received standard care which was the opportunity to have a cervical cytology collected for whatever reason (reference group,n= 33,387). Main outcome measures were detection of cervical intraepithelial neoplasia (CIN) grade 2 or worse (CIN2+) per 1,000 women eligible for the screening offer and the benefit–harm ratio of the intervention and standard practice measured as the number of colposcopies needed to detect one CIN2+ case. The minimum follow-up time was 13 months for all tested women (range: 13 to 25 months). In the intervention group, 6,965 (62.2%) were screened within 12 months from the date of study inclusion and 743 (2.2%) women had a cervical cytology collected in the reference group. The CIN2+ detection was significantly higher in the intervention group (3.9, 95% confidence interval (CI): [2.9, 5.3];p< 0.001;n= 44/11,192) as compared to the reference group (0.3, 95% CI: [0.2, 0.6];n= 11/33,387). For the benefit–harm ratio, 11.6 (95% CI: [8.5, 15.8];p= 0.69;n= 511/44) colposcopies were performed to detect one CIN2+ in the intervention group as compared to 10.1 (95% CI: [5.4, 18.8];n= 111/11) colposcopies in the reference group. The study design entails a risk of confounding due to the lack of randomization.ConclusionsThe higher CIN2+ detection per 1,000 eligible women in the intervention group supports that a catch-up HPV test could potentially improve cervical cancer prevention in older women. This study informs the current scientific debate as to whether women aged 65 and above should be offered a catch-up HPV test if they never had an HPV test.Trial registrationClinicalTrials.govNCT04114968.