Description of statistics and their quality

Quality description assesses the reliability and suitability of statistics of the Finnish Cancer Registry and Mass Screening Registry for different purposes. The quality description follows the recommendations of the Official Statistics of Finland (OSF)

Name of the producer of statistics

Cancer Society of Finland

Quality reporting of statistics of the Finnish Cancer Registry

The cancer statistics quality report evaluates the reliability and suitability of the statistics for different uses. The quality report complies with the recommendations of the Official Statistics of Finland (OSF).

Basis for compilation of the statistics

The maintaining of the register and the compilation of the statistics are based on the Act on the National Institute for Health and Welfare (668/2008), Act on National Personal Records Kept under the Health Care System (556/1989), Decree on National Personal Records Kept under the Health Care System (774/1989) and amendments to it and Personal Data Act (523/1999).

Relevance of statistical information

The cancer statistics contain data on cancer incidence and mortality and on patients’ survival stratified by calendar year, age and sex since the year 1953.  The cancer statistics are presented on a nation-wide basis and by cancer control regions and hospital districts.

The statistics are intended for health care professionals, authorities, designers, researchers and people who need up-to-date information on cancers, including their prevalence and changes to be expected.

Methodological description of statistical research

The Finnish Cancer Registry receives cancer data from:

  • hospitals and other institutions providing treatment for cancer patients
  • health care professionals
  • pathology laboratories
  • Statistics Finland’s cause of death data

In 2017, the majority of clinical notifications are still sent by the hospitals in paper format. The notifications are stored on an electronic database as they arrive. The laboratory notifications are sent and received in electronic format once or twice a year. The cause of death data are updated once a year, immediately after they have been published by Statistics Finland. Checks of the data and the database are always carried out in connection with data entry and updates.

In cancer registration, the goal is to get a clinical notification made by a physician, a laboratory notification, and eventually data on cause of death for every cancer case in Finland.

In the Cancer Registry, a database suitable for statistical purposes and scientific research are created based on the notifications and the cause of death information. The database of the he Finnish Cancer contains data on cancers diagnosed in Finland since 1953.

Validity and accuracy of data

The valisity of data depends on the quality of the information provided. However, several notifications of the same cancer case are received, and these supplement previously received data and confirm cancer diagnoses. If there is conflicting information in the notifications, the information received from the clinical notification is considered to be the most reliable.

Detected errors are corrected on the database. The Finnish Cancer Registry continuously complements, corrects and updates its data. Such amendments appear as small changes in numbers compared to previously published statistics.

The timeliness of published information

The statistics are published annually with about a two-year delay. This delay is because some of the cancer data are submitted for registration with a delay of up to more than a year, and there is about a one-year delay registering and collating all the cause of death data. Upon receipt, data are checked and any errors found are corrected. Internationally, a two-year delay from the date of the diagnosis to the time of the publication of the statistics is considered adequate, as it also allows comprehensive registration of the first phase of cancer treatment.

Availability and transparency of statistics

The statistics are published on the website of the Finnish Cancer Registry, and not in printed format since 2016. There is also a link to the statistics on the website of the National Institute for Health and Welfare. The National Institute for Health and Welfare may grant permission for researchers to use cancer register data for scientific research. For the purpose of acquiring such information, the researcher must first prepare a register description and apply for a research authorisation from the National Institute for Health and Welfare based on the research plan.

Comparability of statistics

The statistics are presented in separate calendar years and/or in longer periods. a. It is possible to make annual, periodic and regional comparisons of data.

Cancer data have been collected since 1953 and are included in the electronic database of the Finnish Cancer Registry. The nationwide registration of cancers in Finland began in 1953, when the National Board of Health issued a circular letter to every doctor, hospital and laboratory in Finland to request them to send a notification of all cancer cases or suspected cancer cases that come to their attention, to be included in cancer statistics. Since 1961, cancer notification has been mandatory in Finland.

Since 1990, the collection of cancer data has been based on a guidance letter (6/1990) of the National Board of Health, concerning notifications of cancer cases to be sent to the Cancer Registry. All cancer notifications since 2008 have been stored and coded by using ICD-O-3 codes (International Classification of Diseases for Oncology, Third Edition, WHO 2000, 1st revision 2013). In earlier years, International Statistical Classification of Diseases from the year 1955 (IDC-7) was used in the coding of cancer notifications.

As the new ICD-O-3 coding system was adopted, the old ICD-7 codes from the year 1955, used for cancer cases stored in the database, were converted automatically by means of a translation matrix into ICD-O-3 codes. Code translation did not improve the accuracy of registered data, but the new codes (since 2008) are more accurate than the previous ones.

Clarity and integrity

The statistical report uses well-established international concepts and classifications. The topography (primary site) and morphology (tissue or cellular, histological diagnosis) of cancer cases are coded according to the International Classification of Cancer Diseases (ICD-O-3). However, clinical ICD-10 codes are used in cancer statistics. The date and cause of death are obtained from Statistics Finland’s cause of death statistics in accordance with the official cause-of-death classification used in the corresponding year. The municipality data and survival data are updated annually from the Population Register Centre. The municipality of residence is defined as the municipality the person resided in at the beginning of the year during which the cancer was diagnosed.