HBV and HIV serological markers: the National External Quality Assessment Scheme in France.

Participation in external quality assessment (EQA) has been mandatory in France as from 1978. The Ministry of Health has responsibility for maintenance of a list of laboratories and contracts EQA schemes to be organised and supervised by scientific groups. Serological markers for viral hepatitis B and anti-HIV were included in surveys, four times per annum, as from 1985. The number of laboratories participating increased from 178 for anti-HIV and 499 for viral hepatitis markers in 1985 to 3421 for anti-HIV and 2384 for viral hepatitis markers at the present time. The percentage of correct results varies depending on the method and specimen from 98% to 99% for anti-HIV and from 95% to 97% for HBsAg; the false negative rate has been as high as 14% for anti-HBs.