Degree of coverage and data quality
All doctors who provide health care to patients with cancer are obliged to report to the Cancer Registry. This includes reporting to the Norwegian Registry of Brain and Spinal Cord Tumours.
For the year 2023, 642 new cases of histologically verified primary tumors of the brain, spinal cord and spinal canal, as well as brain and spinal cord membranes have been recorded. Because of the low coverage of the clinical report, it is the histologically verified tumours that mainly constitute the data basis for all analyses in this annual report.
All patients with brain and spinal cord tumors in Norway must be included in the register. For patients with pituitary tumors, a technical error has led to insufficient reporting of pathology information until the second half of 2023. Therefore, histologically verified pituitary tumors have been omitted from this year's report.
The reporting of tumors in the brain, spinal cord and spinal canal, brain and spinal cord membranes, and pituitary, which have not been histologically verified, is insufficient. We have therefore not calculated the completeness for these tumors in this year's report.
The completeness for gliomas registered in the Cancer Registry in the period 2002–2021 is estimated at 98.8 %. The coverage rate for clinical notification for 2023 is 46.7 % for patients with a histologically verified diagnosis.
During the preparation of the annual report, we found that the reporting of tumours in the brain, spinal cord and spinal canal, brain and spinal cord membranes and pituitary gland, which has not been histologically verified, is inadequate. We have therefore not estimated the completeness of these tumours in the Cancer Registry of Norway in this report. The annual report (Norwegian only) shows that the clinical notification coverage rate for patients with a histologically verified tumour is 33.1 % for the country as a whole.
Coverage rate of clinical notification for histologically verified tumors of the brain, spinal cord and spinal canal, as well as brain and spinal cord membranes, by area of residence, 2023. From fig. 4.1 in the annual report.
The coverage is low and far below both moderate (yellow) and good (green) goal attainment. There is great variation between the health regions and the hospitals. The coverage rate has increased from 33.1 % in 2022, but is still too low. Increasing the reporting of the new clinical reports is one of the advisory board's main focus areas in 2024.
Data quality
Quality assurance of data is done as an integral part of the coding and registration process. In addition, the following examples help to ensure data quality in the Cancer Registry:
- Several independent sources report information
- The information is reported at several points in the course of the disease
- The completeness of the quality register is calculated and assessed through annual coverage rate analyses
- The employees have unique expertise in coding cancer cases according to the Cancer Registry's own code book and international coding systems
- IT systems have rules and barriers for illogical combinations, incorrect information and more
- The Cancer Registry of Norway conducts analyses and control runs that reveal inconsistency in the data
- Data extraction for researchers makes it possible to check a smaller data set of information that can reveal individual errors (e.g. incorrect entry of hospital codes) or systematic differences due to different interpretations of coding systems and rules
- The quality register annually performs a validity analysis where information on radiation therapy and drug cancer treatment registered in the Cancer Register is compared with information on radiation therapy and drug cancer treatment registered in the Norwegian Patient Register