The impact of HPV vaccination on future cervical screening: a simulation study of two birth cohorts in Denmark.
OBJECTIVE
To explore the interplay between primary and secondary prevention of cervical cancer by estimating future screening outcomes in women offered human papillomavirus (HPV) vaccination when they were sexually naïve.


METHODS
Estimation of outcome of liquid-based cytology screening for a post-HPV vaccination cohort using pre-vaccination screening data combined with HPV vaccination efficacy data reported in the literature.


METHODS
Denmark.


METHODS
The number of screening diagnoses at first screen in a pre-vaccination birth cohort was multiplied by reported risk reductions expected for women who were vaccinated for HPV before sexual debut. All identified studies were reviewed by two authors, and weighted pooled estimates of vaccine efficacies were used.


METHODS
Proportions of positive and false-positive cervical cytologies and positive predictive value (PPV) were calculated using cervical intraepithelial neoplasia (CIN) grade 2+ and 3+ as cut-off values.


RESULTS
The proportion of positive screening tests was reduced from 8.7% before vaccination to 6.5% after vaccination, and the proportion of false-positive screening tests using CIN2+ as a cut-off was reduced from 5.5% pre-vaccination to 4.3% post-vaccination, and using CIN3+ as a cut-off from 6.2% to 4.7%. PPVs were reduced from 23% to 19% (cut-off CIN2+), and from 14% to 12% (cut-off CIN3+).


CONCLUSIONS
In our calculations, the proportion of positive screening results with liquid-based cytology will be reduced as a consequence of HPV vaccination, but the reduction is small, and the expected decline in PPV is very limited. In this situation, the information general practitioners will have to provide to their patients will be largely unchanged.
The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Mie Sara
MS
Hestbech
Department of Public Health, Center of Epidemiology and Screening, University of Copenhagen, Copenhagen, Denmark.
Elsebeth
E
Lynge
The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Jakob
J
Kragstrup
The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Volkert
V
Siersma
Department of Public Health, Center of Epidemiology and Screening, University of Copenhagen, Copenhagen, Denmark.
Miguel
M
Vazquez-Prada Baillet
The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
John
J
Brodersen
D000328:Adult; D003718:Denmark; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000517:prevention & control*; D053918:Papillomavirus Vaccines; D011237:Predictive Value of Tests; D011322:Primary Prevention; D040242:Risk Reduction Behavior; D055502:Secondary Prevention; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000517:prevention & control* / Q000821:virology; D014626:Vaginal Smears; D055815:Young Adult
D053918:Papillomavirus Vaccines
PRIMARY CARE