[Better quality of thrombotest in family practice. Results from the NOKLUS survey 1993-97]

The Norwegian centre for external quality assurance of primary health care laboratories (Norwegian abbreviation: NOKLUS) was established in 1992. In 1997 about 1,800 practices participated in NOKLUS' quality assurance schemes, and 576 of these participated in the PT survey. Participation is voluntary and free of charge. The interlaboratory variation (CV%) was 17.7% in 1993 and 13.3% in 1997, and the percentage of results classified as "poor" has decreased from 7-8% in 1993 to 4% in 1997. These data indicate that participation in the scheme has led to a widespread improvement in laboratory performance. Norwegian primary health care practices now seem to analyse PT just as accurately as the Norwegian hospital laboratories. Logistic regression showed that the two most important factors for ensuring quality analysis were having a medical laboratory technician perform the PT analyses, and using an analyzer rather than a manual procedure.