Are there flaws in the follow-up of women with low-grade cervical dysplasia in Ontario?

BACKGROUND

When cervical cytology screening shows atypical squamous cells of unknown significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL), and cervical cytology screening has not been performed in the previous year, it is recommended that cytology screening be repeated six months later. Women with persistent abnormalities should be referred for colposcopy. We explored provincial databases in Ontario to determine whether these recommendations were always followed.

METHODS

Cervical cytology reports in Ontario are contained in a provincial database, deterministically linkable to other health services databases, including those recording physician reimbursement claims for colposcopy. We identified all women in Ontario who had a first time diagnosis of ASCUS or LSIL in 2008 or 2009. We searched for additional cytology reports and for colposcopy billing claims during the 24 months following the date of the first abnormal report. We assessed the interaction of socioeconomic status, having abnormal cytology, and having repeat cytology after a report of low-grade abnormal cervical cytology.

RESULTS

A total of 74 770 women had a first time report of low-grade abnormal cytology. Among women with ASCUS and LSIL, 69.7% and 60.3%, respectively, underwent repeat cytology. Repeat cytology following ASCUS disclosed normal (68.2%), ASCUS (19.3%), LSIL (10.6%), and high-grade squamous intraepithelial lesion (1.4%); following LSIL, the corresponding percentages were 48.3%, 18.0%, 30.8%, and 2.6%. Of women with ASCUS, 16.2% went directly for colposcopy; 14.0% did not repeat cytology or go for colposcopy. Of women with LSIL, 26.4% went directly for colposcopy but 13.4% had no follow-up.

CONCLUSION

We have demonstrated the potential for substantial improvement in cervical cytology six months after a finding of ASCUS and LSIL. We found that many women with ASCUS and LSIL had unnecessary referrals directly for colposcopy, and we identified a lack of follow-up for one sixth of women with low-grade abnormal cytology.