Repeating cytology at initial colposcopy does not improve detection of high-grade abnormalities: a retrospective cohort study of 6595 women.

OBJECTIVE: To determine if repeating a smear improves detection of high-grade pre-invasive or invasive disease of the cervix compared with women who do not have a repeat smear at the time of the initial colposcopic assessment for referral of an abnormal smear. DESIGN: Retrospective cohort study. SETTING: All Wales Colposcopy database. POPULATION: The cohort included women referred for colposcopy with an abnormal smear result, who were seen between 1st January 2002 and 31st December 2002. METHOD: The management of the group of women who had a repeat smear was compared with the group who did not have a repeat smear test at their first visit. Confidence interval analysis was used to compare results between the two groups. MAIN OUTCOME MEASURE: The positive predictive value and sensitivity of the repeat smear to predict outcome, compared to the referral smear in cases where a smear was not repeated at the colposcopy clinic. RESULTS: 3505 cases (54.0%) did not have a repeat smear at initial colposcopy, whereas 2990 (46%) did. There was a significantly higher rate of referral for low-grade dyskaryosis in the group who had repeat smear testing. The median time interval from the referral smear to the first colposcopy was 49 days for both groups. The specificity and positive predictive value for high-grade lesions were significantly higher in the repeat smear results. The sensitivity was significantly lower, and a high-grade lesion would have been missed with the repeat smear in 14.0% of all referrals. CONCLUSIONS: Colposcopists appeared more inclined to repeat smears for low-grade referrals. The time interval from the referral smear to colposcopy did not appear to influence this decision. A repeat smear test at the first colposcopy visit will detect less high-grade pre-invasive or invasive disease than the initial referral smear.

The inadequate smear: does it matter?

The objective of this study was to quantify the incidence of underlying cervical intraepithelial neoplasia (CIN) among women referred for colposcopy with three consecutive inadequate smears. The design was a retrospective cohort study analysing data from a regional colposcopy database at Cervical Screening Wales. Women who were referred to all the colposcopy clinics in Wales with three consecutive inadequate smears, the third inadequate smear being taken between 1 April 2001 and 31 March 2002 constituted the study population. The results of the fourth smear taken at the colposcopy clinic after three consecutive inadequate smears, the worst biopsy results from any of the subsequent colposcopies and the relationship between the result of the fourth smear taken at colposcopy clinic and any histology result were the main outcome measures. The accuracy of the colposcopic opinion was also examined. Of the 433 women identified as having been referred because of three consecutive inadequate smears, 302 were linked to either a subsequent smear and/or a biopsy result. An adequate smear result was available for 85% of these women when the smear was taken in the colposcopy clinic; 77% were reported as negative and 8% were abnormal. Of the 347 women seen in the colposcopy clinic, high-grade CIN was seen in 3% and low-grade lesion in 8%. The sensitivity and specificity of the fourth inadequate smear test in predicting underlying CIN were 15% and 84% respectively, with a positive predictive value of 8%. The sensitivity and specificity of colposcopy in predicting histological CIN among patients with three inadequate smears was 70% and 49%, respectively, and the positive predictive value was 44%. This study raises the question as to whether three consecutive inadequate smears should be considered as an indication for colposcopy, or merely for a further smear to be taken in circumstances where there is a greater likelihood getting an adequate result.