Data quality at the Cancer Registry of Norway: an overview of comparability, completeness, validity and timeliness.

AIM

To provide a comprehensive evaluation of the quality of the data collected on both solid and non-solid tumours at the Cancer Registry of Norway (CRN).

METHODS

Established quantitative and semi-quantitative methods were used to assess comparability, completeness, accuracy and timeliness of data for the period 1953-2005, with special attention to the registration period 2001-2005.

RESULTS

The CRN coding and classification system by and large follows international standards, with some further subdivisions of morphology groupings performed in-house. The overall completeness was estimated at 98.8% for the registration period 2001-2005. There remains a variable degree of under-reporting particularly for haematological malignancies (C90-95) and tumours of the central nervous system (C70-72). For the same period, 93.8% of the cases were morphologically verified (site-specific range: 60.0-99.8%). The under-reporting in 2005 due to timely publication is estimated at 2.2% overall, based on the number of cases received at the registry during the following year.

CONCLUSION

This review suggests the routines in place at the CRN yields comparable data that can be considered reasonably accurate, close-to-complete and timely, thereby justifying our policy of the reporting of annual incidence one year after the year of diagnosis.