title: Short interval between two Pap smears: effect on the result of the second smear? A prospective randomized trial.
abstract: OBJECTIVE
  A repeat Pap smear is sometimes necessary after a short time interval or even immediately, when patients seek for a second opinion or due to study participation. Only limited information is available on the possible impact of a short interval between two Pap smears. Most institutions therefore practice a minimum time span of 6-8 weeks before obtaining a second smear since a short interval is commonly believed to be associated with an increase of false negative results in the second smear.
  
  
  METHODS
  Two consecutive Pap smears were obtained from 81 women. 41 smears were processed using the conventional technique, whereas liquid-based cytology was used in the remaining 40 women. Smears were independently evaluated by four different cytopathologists. We analyzed the effect of time interval, both processing techniques and inter-observer variance in cytological evaluation.
  
  
  RESULTS
  While the result of the second smear shows a tendency towards a more benign outcome (odds ratio (OR) 1.436, 95% CI 0.972-2.121), this difference was not statistically significant (p = 0.07). No significant differences were observed between conservative and liquid-based cytology (OR 1.554, 95% CI 0.659-3.667, p = 0.31). There was considerable inter-observer variability, and the observer was a strong predictor of the cytological result (OR 0.632-5.083, 95% CI 0.355-8.975, p < 0.01).
  
  
  CONCLUSIONS
  We document a tendency towards a more benign outcome without statistical significance in the second smear. Inter-observer variability of different cytopathologists is high and should be kept in mind when evaluating cytology results.
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany. Theresa.Kolben@med.uni-muenchen.de.
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Kolben
authors.affiliation: Amedes MVZ for Gynecology and Pathology Munich GmbH, Munich, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Bergauer
authors.affiliation: Laboratory for Cytodiagnostics, Freiburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Moeckel
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Berit
authors.initials: B
authors.lastname: Boettcher
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Thaler
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kolben
authors.affiliation: Department of Medical Informatics, Biometry and Epidemiology, University of Munich, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Crispin
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Dannecker
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Mahner
authors.affiliation: Department for Obstetrics and Gynecology, University Hospital Munich, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Gallwas
mesh_terms: D000328:Adult; D000368:Aged; D002584:Cervix Uteri / Q000473:pathology*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015588:Observer Variation; D016017:Odds Ratio; D065006:Papanicolaou Test / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis; D014626:Vaginal Smears / Q000379:methods*; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis
keywords: Cervical cytology; Cervical dysplasia; HPV; Liquid-based cytology; Pap smear