Process performance of cervical screening programmes in Europe.

Standardised tables of aggregated data were collected from 15 European national or regional cervical screening programmes and key performance indicators computed as reported in European Union (EU) Guidelines, 2nd edition. Cytological results varied widely between countries both for the total proportion of abnormal tests (from 1.2% in Germany (Mecklenburg-Vorpommern) to 11.7% in Ireland-Midwest Region) and for their distribution by grade. Referral rates for repeat cytology (ranging from 2.9% of screened women in the Netherlands to 16.6% in Slovenia) or for colposcopy (ranging from 0.8% in Finland to 4.4% in Romania-Cluj) and the Positive Predictive Value (PPV) of colposcopic attendance (ranging from 8% in Romania-Cluj to 52% in Lithuania) were strongly influenced by management protocols, in particular for atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cytology. However, cytology-specific PPV also showed remarkable variability. The detection rate of CIN2+ histology ranged from <0.1% of screened women in Poland to >1% in England and Denmark. Low attendance for colposcopy after referral was observed in some east-European countries. These comparisons may be useful for improving the performance of cervical screening in general and more so if new screening technologies and vaccination for Human Papillomavirus are introduced. Overall, quality was better in countries that have operated organised programmes for a longer time, plausibly as a result of long-lasting monitoring and quality assurance activities. Therefore, the availability of these data, the first comparing European countries, and the increased number of countries that can provide such data (only five in 2004) represent progress. Nevertheless, there is a clear need to standardise the cytological and histological classifications used in screening, as well as data registration systems across Europe.