Degree of coverage and data quality in the Colorectal Cancer Registry

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Degree of coverage and completeness

All patients with colorectal cancer in Norway must be included in the registry. The Cancer Registry's basic registry contains information on 99.7 per cent of all patients diagnosed with colon cancer and 99.9 per cent with end-cancer cancer.

All doctors who provide health care to patients with cancer are obliged to report to the Cancer Registry. This includes reporting to the National Quality Register for Colon and Rectal Cancer. Colorectal cancer is assessed and/or treated at all hospitals in Norway, and all hospitals report to the Cancer Registry.

Results for the coverage rate for assessment report and surgery report 2022:

• Colorectal cancer assessment report: 74.1 %
• Colon cancer surgery report: 84.9%
• Rectal cancer assessment report: 74.6 %
• Rectal cancer surgery report: 89.8%

The annual report for colorectal cancer will be published much earlier in 2022, which may explain a lower result on the coverage of clinical information compared to 2021. In 2022, the Quality Register and the Professional Council have continued to maintain focus on increasing reporting, but there is still a lower coverage rate for assessment reports than surgery reports. The well-established cooperation with the contact persons at the hospitals is an important factor for the results. The quality register also regularly receives inquiries with requests related to reporting.

The degree of coverage of clinical reports for each hospital is specified in the annual report (Norwegian only).

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 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