title: Collection devices for obtaining cervical cytology samples.
abstract: OBJECTIVE
  The false-negative rate of cervical smears varies between 1.5% and 55%. This variation may be partly due to differences in sampling device and technique. The objective of this review was to assess different cervical sampling devices for collecting endocervical cells, which are thought to be a surrogate for detection of abnormal cells and adequate smear rates.
  
  
  METHODS
  We searched the Cochrane Gynaecological Cancer Group trials register and MEDLINE up to July 1997. We also handsearched 16 journals.
  
  
  METHODS
  Randomised and quasi-randomised trials and non-randomised comparative studies comparing cervical smear collection devices in women attending for primary screening, colposcopy following an abnormal smear or colposcopy after treatment.
  
  
  METHODS
  Two reviewers independently abstracted data. Study quality was assessed.
  
  
  RESULTS
  Thirty-four trials and six observational comparative studies were included. The Ayre spatula was shown to be less effective compared with extended tip spatulas for collecting endocervical cells in eight trials (odds ratio 2.25, 95% confidence interval 2.06 to 2.44). Use of a spatula with the cytobrush was more effective than spatula alone at collecting endocervical cells (odds ratio 3.33, 95% 3.05 to 3.63) and the same effect was present for adequate smear rates (odds ratio 1.51 95% 1.19-1.92). Extended tip spatulas were also superior for the detection of dyskaryosis in seven trials (odds ratio 1.21, 95% confidence interval 1.10 to 1.33). Based on data from two trials and three observational studies, smears that contained endocervical cells were more likely to detect dyskaryosis, particularly in severe disease. The proportion of smears with endocervical cells present increased with increasing severity of the disease.
  
  
  CONCLUSIONS
  Extended tip spatulas of various designs appear to be better for collecting endocervical cells than the commonly used Ayre spatula. The most effective combination appears to be the cytobrush with an extended tip spatula. The rate of detection of endocervical cells appears to be a valid and convenient surrogate for the ability to detect dyskaryosis and for adequate smear rates. The ability of the extended tip spatula with the cytobrush compared with the extended tip spatula alone to detect disease, needs to be evaluated in a trial.
authors.affiliation: University Department of Obstetrics and Gynaecology, St Mary's Hospital, Whitworth Park, Manchester, UK, M13 0JH.
authors.forename: P
authors.initials: P
authors.lastname: Martin-Hirsch
authors.forename: G
authors.initials: G
authors.lastname: Jarvis
authors.forename: H
authors.initials: H
authors.lastname: Kitchener
authors.forename: R
authors.initials: R
authors.lastname: Lilford
mesh_terms: D005260:Female; D006801:Humans; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis*; D014626:Vaginal Smears / Q000295:instrumentation*