Klin Onkol 2007; 20(Suppl 1 20): 63-76.
The paper is focused on quality assessment of cancer population-based registries. The analyses are methodically based on the database of Czech National Cancer Registry (NCR) that offers valuable model with epidemiological data of all diagnostic groups of cancer, all collected continuously since 1977. Quality control is necessary for applications of NCR in health care evaluation and for international
presentation of Czech cancer epidemiology. The audit resulted in a set of diagnostically completed and verified records and in a set of records with incomplete diagnostics (namely TNM) due to well distinguished objective reasons (DCO cases, cases diagnosed at autopsy, early death after diagnosis, etc.). All the objective reasons were recognized and the database was enriched by codes that
identify the status of the record and its reason. In addition to it, we found 5.1 % of cases with wrong and/or incomplete diagnostics and without any acceptable explanation. These cases typologically correspond to the whole NCR database and so they can be excluded from serious analyses with a minimum risk of bias. Increased probability of bias due to erroneously incomplete records exists only in
regionally specific comparisons.
