title: Exploring the trend of increased cervical intraepithelial neoplasia detection rates in the Netherlands.
abstract: OBJECTIVE
  Over the last decade, cervical intraepithelial neoplasia (CIN) detection has increased in the Netherlands. We investigated the underlying mechanism by quantifying the increase, and analyzing patterns of CIN and cervical cancer detection over time.
  
  
  METHODS
  We observed annual CIN and cervical cancer detection rates (DRs) per 10,000 primary smears within the Dutch screening programme for 2000-2011. Joinpoint analyses were performed to determine changes in time trends, logistic regression analyses to assess the relative risk of calendar time on histological outcomes, adjusted for demographic factors and type of primary cytology test used.
  
  
  RESULTS
  Trends of increased detection occurred for all CIN grades (ie. DRs increased from 17.8 to 36.1, from 21.0 to 35.5, and from 43.4 to 64.6 for CIN I, II, and III from 2003 to 2009). After adjusting for demographic factors, DRs were still 2.11 (95% confidence interval (CI): 1.95, 2.29), 1.79 (95% CI: 1.66, 1.92) and 1.59 (95% CI: 1.50, 1.67) times larger in 2009. When also adjusting for the type of cytology test, DRs were 1.90 (95% CI: 1.62, 2.22), 1.48 (95% CI: 1.22, 1.79) and 1.55 (95% CI: 1.39, 1.73) times larger. No trends in cervical cancer DRs were found.
  
  
  CONCLUSIONS
  The implementation of liquid-based cytology contributed to the CIN increase. If some of these extra detected CIN are regressive this leads to overdiagnosis. Other factors, such as an increased cervical cancer risk, and implementation of imaging-assisted reading, could also have contributed.
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands k.rozemeijer@erasmusmc.nl.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Rozemeijer
authors.affiliation: Erasmus MC, University Medical Center, Department of Pathology, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Folkert J
authors.initials: FJ
authors.lastname: van Kemenade
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Corine
authors.initials: C
authors.lastname: Penning
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Suzette M
authors.initials: SM
authors.lastname: Matthijsse
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Steffie K
authors.initials: SK
authors.lastname: Naber
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands Erasmus MC, University Medical Center, Department of Biostatistics, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Joost
authors.initials: J
authors.lastname: van Rosmalen
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: van Ballegooijen
authors.affiliation: Erasmus MC, University Medical Center, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands.
authors.forename: Inge M C M
authors.initials: IM
authors.lastname: de Kok
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012044:Regression Analysis; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000453:epidemiology*
keywords: cervical cancer; cervical intraepithelial neoplasia; screening; trend