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Kim H, Kim KY, Kim D, Hwang JH. Implementation rate and related factors of confirmatory tests following an abnormal Pap smear: a nationwide study from the National Health Insurance. J Gynecol Oncol 2024; 35:e26. [PMID: 38130135 PMCID: PMC11107272 DOI: 10.3802/jgo.2024.35.e26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/17/2023] [Accepted: 11/26/2023] [Indexed: 12/23/2023] Open
Abstract
OBJECTIVE This study aims to investigate the implementation rate and influencing factors of confirmatory tests for women with abnormal cervical cytology results in the Korean nationwide cervical cancer screening program. METHODS The National Health Insurance Service (NHIS) database was utilized to identify all Korean women who have participated in the Korean nationwide cervical cancer screening program from January 2011 and December 2021 using the NHIS database. Multiple logistic regression analysis was performed to estimate the multivariate odds ratio and evaluate the patients' characteristics. RESULTS The rate of abnormal Papanicolaou (Pap) smears showed an initial increase from 2011 to 2015 and subsequently reached a plateau after 2016. When examining specific subcategories, cases of atypical squamous cells of undetermined significance (ASC-US) increased from 28,546 cases (1.1%) in 2011 to 62,850 cases (1.7%) in 2021. In contrast, cases of HSIL and SCC declined from 3,535 cases (0.14%) to 2,763 cases (0.07%) and from 383 cases (0.01%) to 179 cases (0.005%), respectively. Furthermore, the implementation rate of confirmatory tests for women with abnormal cytology increased from 8,865 cases (21.0%) in 2011 to 39,045 cases (51.2%) in 2021. Regarding the specific subcategory of ASC-US, the number of confirmatory tests exhibited a substantial increase from 4,101 cases (14.4%) in 2011 to 30,482 cases (48.5%) in 2021. For SCC, there was no significant change, with 216 cases (56.4%) in 2011 and 102 cases (57.0%) in 2021. The implementation rate of confirmatory tests was found to be significantly associated with results of abnormal Pap smear, age, and residence. Notably, economic status did not emerge as a significant factor affecting the likelihood of undergoing confirmatory tests. CONCLUSIONS The severity of abnormal Pap smear results is a reliable indicator of the probability of undergoing a confirmatory test. Additional endeavors are required to improve the implementation rate among women who have received abnormal Pap smear results.
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Affiliation(s)
- Hyeongsu Kim
- Department of Preventive Medicine, Konkuk University School of Medicine, Seoul, Korea
| | - Kyeong Yeon Kim
- Department of Occupational and Environmental Medicine Center, Korea Medical Institute, Seoul, Korea
| | - Dasom Kim
- Home Visit Healthcare Team, Expert Group on Health Promotion for Seoul Metropolitan Government, Konkuk University, Seoul, Korea
| | - Jong Ha Hwang
- Department of Obstetrics and Gynecology, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, Korea.
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Rebolj M, Brentnall AR, Cuschieri K. Predictable changes in the accuracy of human papillomavirus tests after vaccination: review with implications for performance monitoring in cervical screening. Br J Cancer 2024; 130:1733-1743. [PMID: 38615108 PMCID: PMC11130303 DOI: 10.1038/s41416-024-02681-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/15/2024] Open
Abstract
Vaccination against human papillomavirus (HPV) is changing the performance of cytology as a cervical screening test, but its effect on HPV testing is unclear. We review the effect of HPV16/18 vaccination on the epidemiology and the detection of HPV infections and high-grade cervical lesions (CIN2+) to evaluate the likely direction of changes in HPV test accuracy. The reduction in HPV16/18 infections and cross-protection against certain non-16/18 high-risk genotypes, most notably 31, 33, and/or 45, will likely increase the test's specificity but decrease its positive predictive value (PPV) for CIN2+. Post-vaccination viral unmasking of non-16/18 genotypes due to fewer HPV16 co-infections might reduce the specificity and the PPV for CIN2+. Post-vaccination clinical unmasking exposing a higher frequency of CIN2+ related to non-16/18 high-risk genotypes is likely to increase the specificity and the PPV of HPV tests. The effect of HPV16/18 vaccination on HPV test sensitivity is difficult to predict based on these changes alone. Programmes relying on HPV detection for primary screening should monitor the frequency of false-positive and false-negative tests in vaccinated (younger) vs. unvaccinated (older) cohorts, to assess the outcomes and performance of their service.
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Affiliation(s)
- Matejka Rebolj
- Centre for Cancer Screening, Prevention, and Early Detection, Wolfson Institute of Population Health, Queen Mary University of London, London, UK.
| | - Adam R Brentnall
- Centre for Evaluation and Methods, Wolfson Institute of Population Health, Queen Mary University of London, London, UK
| | - Kate Cuschieri
- Scottish HPV Reference Laboratory, Royal Infirmary of Edinburgh, NHS Lothian Scotland, Edinburgh, UK
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Krog L, Lycke KD, Kahlert J, Randrup TH, Jensen PT, Rositch AF, Hammer A. Risk of progression of cervical intraepithelial neoplasia grade 2 in human papillomavirus-vaccinated and unvaccinated women: a population-based cohort study. Am J Obstet Gynecol 2024; 230:430.e1-430.e11. [PMID: 38569830 DOI: 10.1016/j.ajog.2023.11.1235] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 04/05/2024]
Abstract
BACKGROUND Many countries have implemented active surveillance (ie, leaving the lesion untreated) as an option among younger women with cervical intraepithelial neoplasia grade 2 because regression rates are high and excisional treatment increases the risk for preterm birth in subsequent pregnancies. However, early identification of women at increased risk for progression to cervical intraepithelial neoplasia grade 3 or worse is important to ensure timely treatment. Because women who have received a human papillomavirus vaccine have a lower risk for cervical cancer, they may have a lower risk for progression of untreated cervical intraepithelial neoplasia grade 2 to cervical intraepithelial neoplasia grade 3 or worse. OBJECTIVE This study aimed to investigate if women who received a human papillomavirus vaccine and who are undergoing active surveillance for cervical intraepithelial neoplasia grade 2 are less likely to progress to cervical intraepithelial neoplasia grade 3 or worse when compared with women who did not receive the vaccine. STUDY DESIGN We conducted a population-based cohort study in Denmark using data from national health registers. We identified all women aged 18 to 40 years who were undergoing active surveillance for cervical intraepithelial neoplasia grade 2 from January 1, 2007, to December 31, 2020. Women with a previous record of cervical intraepithelial neoplasia grade 2 or worse, hysterectomy, or a loop electrosurgical excision procedure were excluded. Exposure was defined as having received ≥1 dose of a human papillomavirus vaccine at least 1 year before the cervical intraepithelial neoplasia grade 2 diagnosis. We used cumulative incidence functions to estimate the risk for progression to cervical intraepithelial neoplasia grade 3 or worse within 28 months using hysterectomy, emigration, and death as competing events. We used modified Poisson regression to calculate crude and adjusted relative risks of progression during the 28-month surveillance period. Results were stratified by age at vaccination and adjusted for index cytology, disposable income, and educational level. RESULTS The study population consisted of 7904 women of whom 3867 (48.9%) were vaccinated at least 1 year before a diagnosis of cervical intraepithelial neoplasia grade 2. At the time of cervical intraepithelial neoplasia grade 2 diagnosis, women who were vaccinated were younger (median age, 25 years; interquartile range, 23-27 years) than those who were not (median age, 29 years; interquartile range, 25-33 years). The 28-month cumulative risk for cervical intraepithelial neoplasia grade 3 or worse was significantly lower among women who were vaccinated before the age of 15 years (22.9%; 95% confidence interval, 19.8-26.1) and between the ages of 15 and 20 years (31.5%; 95% confidence interval, 28.8-34.3) when compared with women who were not vaccinated (37.6%; 95% confidence interval, 36.1-39.1). Thus, when compared with women who were not vaccinated, those who were vaccinated before the age of 15 years had a 35% lower risk for progression to cervical intraepithelial neoplasia grade 3 or worse (adjusted relative risk, 0.65; 95% confidence interval, 0.57-0.75), whereas women who were vaccinated between the ages of 15 and 20 years had a 14% lower risk (adjusted relative risk, 0.86; 95% confidence interval, 0.79-0.95). For women who were vaccinated after the age of 20 years, the risk was comparable with that among women who were not vaccinated (adjusted relative risk, 1.02; 95% confidence interval, 0.96-1.09). CONCLUSION Women who were vaccinated and who were undergoing active surveillance for cervical intraepithelial neoplasia grade 2 had a lower risk for progression to cervical intraepithelial neoplasia grade 3 or worse during 28 months of follow-up when compared with women who were not vaccinated but only if the vaccine was administered by the age of 20 years. These findings may suggest that the human papillomavirus vaccination status can be used for risk stratification in clinical management of cervical intraepithelial neoplasia grade 2.
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Affiliation(s)
- Louise Krog
- Department of Obstetrics and Gynecology, Gødstrup Hospital, Herning, Denmark; NIDO | Centre for Research and Education, Gødstrup Hospital, Herning, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark.
| | - Kathrine D Lycke
- Department of Obstetrics and Gynecology, Gødstrup Hospital, Herning, Denmark; NIDO | Centre for Research and Education, Gødstrup Hospital, Herning, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
| | - Johnny Kahlert
- Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Tina H Randrup
- Department of Obstetrics and Gynecology, Gødstrup Hospital, Herning, Denmark; NIDO | Centre for Research and Education, Gødstrup Hospital, Herning, Denmark
| | - Pernille T Jensen
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark; Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark; Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Anne F Rositch
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Anne Hammer
- Department of Obstetrics and Gynecology, Gødstrup Hospital, Herning, Denmark; NIDO | Centre for Research and Education, Gødstrup Hospital, Herning, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
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Kurosawa M, Sekine M, Yamaguchi M, Kudo R, Hanley SJB, Hara M, Adachi S, Ueda Y, Miyagi E, Ikeda S, Yagi A, Enomoto T. Long-Term Effects of Human Papillomavirus Vaccination in Clinical Trials and Real-World Data: A Systematic Review. Vaccines (Basel) 2022; 10:vaccines10020256. [PMID: 35214713 PMCID: PMC8877934 DOI: 10.3390/vaccines10020256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 12/04/2022] Open
Abstract
The preventive effect of HPV vaccines against anogenital and oropharyngeal cancers has been proven in both clinical trials and real-world data. We reviewed the published evidence about the long-term efficacy and effectiveness of the HPV vaccine in available papers of clinical trials and real-world data. As far as we searched, the longest period of preventive effect for the bivalent, 4-valent, and 9-valent vaccine were 11 years in the Costa Rica trial, 14 years in the FUTURE II, and 8 years in the LTFU extension study of V503-002 and the Scandinavian study, respectively. The sustained clinical effect during the observation period was longest for the 4-valent vaccine. In real-world data, the longest observation period of the vaccine effectiveness was 12 years in an Australian study for the 4-valent vaccine. On the other hand, the longest period of long-term persistence of HPV vaccine-induced seropositivity was 14 years in FUTURE II for the 4-valent vaccine. For the bivalent vaccine, additional long-term follow-up studies may not have been planned due to the launch of the 4-valent and 9-valent vaccines. In some studies of the 9-valent vaccine, the results have not yet been published because of the short observation period. The additional results are expected in the future. In a national immunization program, most girls and boys are inoculated with HPV vaccine by the time puberty begins; thus, it is important to monitor the vaccine effect at least until the sexually active period in their 20s and 30s.
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Affiliation(s)
- Megumi Kurosawa
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
| | - Masayuki Sekine
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
- Correspondence:
| | - Manako Yamaguchi
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
| | - Risa Kudo
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
| | - Sharon J. B. Hanley
- Center for Environmental and Health Sciences, Hokkaido University, Sapporo 060-8638, Japan;
| | - Megumi Hara
- Department of Preventive Medicine, Faculty of Medicine, Saga University, Saga 849-8501, Japan;
| | - Sosuke Adachi
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
| | - Yutaka Ueda
- Departments of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan; (Y.U.); (A.Y.)
| | - Etsuko Miyagi
- Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Yokohama 236-0004, Japan;
| | - Sayaka Ikeda
- Division of Surveillance and Policy Evaluation, Institute for Cancer Control, National Cancer Center, Tokyo 104-0045, Japan;
| | - Asami Yagi
- Departments of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan; (Y.U.); (A.Y.)
| | - Takayuki Enomoto
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan; (M.K.); (M.Y.); (R.K.); (S.A.); (T.E.)
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Kurosawa M, Sekine M, Yamaguchi M, Kudo R, Hanley SJB, Hara M, Adachi S, Ueda Y, Miyagi E, Ikeda S, Yagi A, Enomoto T. Long-term effectiveness of HPV vaccination against HPV infection in young Japanese women: real-world data. Cancer Sci 2022; 113:1435-1440. [PMID: 35100477 PMCID: PMC8990292 DOI: 10.1111/cas.15282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/04/2022] [Accepted: 01/18/2022] [Indexed: 11/28/2022] Open
Abstract
In Japan, public funding for HPV vaccination began in 2010 for girls aged 13–16 years (birth cohort years 1994–1997) and women born in 1994 who turned 25 in 2019. We aimed to verify the long‐term effectiveness of the bivalent HPV vaccine in women aged 25 years. Subjects were women aged 25–26 years who underwent cervical cancer screening and HPV testing in Niigata from 2019 to 2020 (birth cohort years 1993–1994). Information on vaccination status and sexual behavior was obtained from a questionnaire and municipal records. We compared the HPV infection rates of the vaccinated and unvaccinated groups. Of the 429 registrants, 150 (35.0%) and 279 (65.0%) were vaccinated and unvaccinated, respectively. The average period from HPV vaccination to HPV testing was 102.7 months (8.6 years), with a median of 103 months (range 92–109 months). The HPV high‐risk infection rate was 21.3% (32/150) in the vaccinated group and 23.7% (66/279) in the unvaccinated group (P = 0.63). The HPV16/18 infection rate was 0% (0/150) in the vaccinated group and 5.4% (15/279) in the unvaccinated group, showing a significant difference (P = 0.0018), and the vaccine effectiveness was 100%. The cross‐protective type HPV31/45/52 infection rate in the vaccinated group was significantly lower than that in the unvaccinated group (3.3% vs. 10.0%, P = 0.013). There was no significant difference in the mean age at sexual debut and the number of previous sexual partners between the two groups. We have demonstrated the long‐term 9‐year effectiveness of the bivalent vaccine against HPV infection for the first time in Japan.
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Affiliation(s)
- Megumi Kurosawa
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Masayuki Sekine
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Manako Yamaguchi
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Risa Kudo
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Sharon J B Hanley
- Hokkaido University Center for Environmental and Health Sciences, Sapporo, Japan
| | - Megumi Hara
- Department of Preventive Medicine, Faculty of Medicine, Saga University, Saga, Japan
| | - Sosuke Adachi
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yutaka Ueda
- Departments of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Etsuko Miyagi
- Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Yokohama, Japan
| | - Sayaka Ikeda
- Center for Cancer Control and Information Services, National Cancer Center, Tokyo, Japan
| | - Asami Yagi
- Departments of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takayuki Enomoto
- Department of Obstetrics and Gynecology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Kjaer SK, Dehlendorff C, Belmonte F, Baandrup L. Real-World Effectiveness of Human Papillomavirus Vaccination Against Cervical Cancer. J Natl Cancer Inst 2021; 113:1329-1335. [PMID: 33876216 DOI: 10.1093/jnci/djab080] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/01/2021] [Accepted: 03/23/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The primary goal of human papillomavirus (HPV) vaccination is to reduce morbidity and mortality from HPV-associated disease, especially cervical cancer. We determined the real-world effectiveness of HPV vaccination against cervical cancer. METHODS The study included women aged 17-30 years living in Denmark October 2006-December 2019. From nationwide registries, information on HPV vaccination and cervical cancer diagnoses were retrieved. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for cervical cancer according to vaccination status were estimated using Poisson regression with HPV vaccination treated as a time-varying variable and stratified by age at vaccination. We adjusted for attained age, education, and ethnicity. To address the effect of prevalent disease, different buffer periods were used, with 1-year buffer period as primary analysis. RESULTS The cohort comprised 867 689 women. At baseline, 36.3% were vaccinated at age 16 years and younger, and during follow-up, 19.3% and 2.3% were vaccinated at ages 17-19 years and 20-30 years, respectively. For women vaccinated at ages 16 years and younger or 17-19 years, the IRRs of cervical cancer were 0.14 (95% CI = 0.04 to 0.53) and 0.32 (95% CI = 0.08 to 1.28), respectively, compared with unvaccinated women. In women aged 20-30 years at vaccination, the incidence rate was higher than among unvaccinated women (IRR = 1.19, 95% CI = 0.80 to 1.79) but slightly decreased with increasing buffer period (IRR = 0.85, 95% CI = 0.55 to 1.32, with 4-year buffer period). CONCLUSION HPV vaccine effectiveness against cervical cancer at the population level is high among girls vaccinated younger than age 20 years. The lack of immediate effect in women vaccinated at age 20-30 years points to the importance of early age at vaccination.
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Affiliation(s)
- Susanne K Kjaer
- Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Gynaecology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christian Dehlendorff
- Statistics and Data Analysis, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Federica Belmonte
- Statistics and Data Analysis, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Louise Baandrup
- Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Copenhagen, Denmark
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Schroll JB. Human papilloma virus vaccination and its real‐life efficacy. Acta Obstet Gynecol Scand 2020; 99:1267-1268. [DOI: 10.1111/aogs.13964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeppe Bennekou Schroll
- Department of Obstetrics and Gynecology Copenhagen University Hospital Hvidovre Denmark
- Faculty of Health Sciences University of Copenhagen Copenhagen Denmark
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Thamsborg LH, Napolitano G, Larsen LG, Lynge E. High-grade cervical lesions after vaccination against human papillomavirus: A Danish cohort study. Acta Obstet Gynecol Scand 2020; 99:1290-1296. [PMID: 32754966 PMCID: PMC7540379 DOI: 10.1111/aogs.13935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/18/2020] [Accepted: 05/22/2020] [Indexed: 02/07/2023]
Abstract
Introduction It is pertinent to evaluate the impact of vaccination against human papillomavirus (HPV) in real life. The aim of the study was to evaluate the real‐life impact of HPV vaccination in the first birth cohort of Danish women offered free HPV vaccination as girls and invited to screening at the age of 23 years. Material and methods Women born in 1993 were offered free HPV vaccination at the age of 15 years but women born in 1983 have never been offered free HPV vaccination. We followed these two birth cohorts for 10 years from the age of 15 to after their first invitation to screening, and compared the risk of high‐grade cervical intraepithelial neoplasia (CIN). Data were obtained from Danish national health registers. Results Vaccination coverage was 91% in the 1993 birth cohort and <0.1% in the 1983 cohort. Screening coverage was close to 80% in both cohorts. CIN2+ was detected in 4% of the 15 748 screened women born in 1983 and in 3% of the 19 951 screened women born in 1993. The risk of high‐grade CIN was reduced by about 30% in the 1993 cohort compared with the 1983 cohort; for CIN2+ relative risk 0.74 (95% CI 0.66‐0.82) and for CIN3+ relative risk 0.68 (95% CI 0.58‐0.79). Conclusions This study investigated the real‐life impact of quadrivalent HPV vaccination by comparing a cohort of women offered HPV vaccination with a cohort of women not offered HPV vaccination. The observed decrease in the detection of high‐grade cervical lesions following HPV vaccination is in line with results from the randomized trials and has important implications for future cervical screening of HPV vaccinated cohorts.
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Affiliation(s)
| | - George Napolitano
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Lise Grupe Larsen
- Department of Pathology, Zealand University Hospital, Roskilde, Denmark
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