Quality description

 Cancer registration

 Quality description
 
A quality description of the cancer statistics assesses the reliability and suitability of the statistics for different purposes. The quality description follows the recommendations of the Official Statistics of Finland (OSF).
 
Name of the producer of the statistics
 
Cancer Society of Finland
 
Grounds for compilation of the statistics
 
The maintaining of registers and compilation of 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 rates, arranged according to year of diagnosis, patient age and sex. These data are presented beginning from the year 1953. The data are presented on a nation-wide basis and by regions and hospital districts.
 
The statistics are targeted at healthcare professionals, authorities, those responsible for planning and research and people, who need up-to-date information on cancers, their prevalence and changes to be expected.
 
Concepts, classifications used and instructions for completing cancer notification forms are described on the website of the Finnish Cancer Registry at the following address: http://www.cancer.fi/syoparekisteri/en/registration/.
 
Methodological description
 
The Finnish Cancer Registry receives cancer data
-          from hospitals and other institutions providing treatment for cancer patients
-          from healthcare professionals
-          from pathology laboratories
-          from Statistic Finland’s cause of death data
 
The majority of so-called clinical notifications are sent by the hospitals in paper format. They are immediately recorded in an electronic database. The majority of laboratory notifications are sent in an electronic format once or twice per year. The causes of death data are updated once a year, immediately after they have been published by Statistics Finland. Data and database checks are always carried out in connection with data entry and updates.
 
Cancer registration aims at receiving the following information of each cancer case: a clinical notification made by a doctor, a laboratory notification and eventually data on death. If a clinical notification is noticed to be missing in the registration phase of a new cancer case, the missing clinical data are requested from the hospital in which the patient has been treated. At the time of publication of the cancer statistics, no requests for supplementary information had been made and a clinical notification was missing in 47% of all cancer cases in 2012, which is the most recent statistical year. Of the cancer cases in 2011, a clinical notification was still missing after requests for supplementary information in 24% of the cancer cases.
 
In the Cancer Registry, a database suitable for statistical purposes will be created, based on notifications received and on Statistic Finland's cause of death data. The database will be used for statistical purposes and scientific research. The database of the Finnish Cancer Registry contains data of cancers diagnosed in Finland since 1953.
 
Correctness and accuracy of data
 
The correctness of data depends on the quality of data provided. However, several notifications of the same cancer are received. These will supplement the data previously received and help to confirm cancer diagnoses. If there is conflicting data in the notifications, the data received from a clinical notification is considered to be the most reliable.
 
In contradictory cases data will be checked from the institutions which have provided treatment for the patient. The cause of death data of Statistics Finland will be checked if needed.
 
Any errors noticed will be corrected. The Finnish Cancer Registry is continuously active in supplementing and correcting data. Any changes will be updated accordingly in the statistics and will be visible in form of slightly altered rates compared to previously published statistics.
 
Timeliness and promptness of published data
 
The statistics are published annually, with a delay of approximately two years. This is due to a delay of more than a year in submitting part of the cancer data for registration, and a delay of approximately a year in submitting all data on death. When the data have been submitted, after this the data will be checked, errors will be corrected and a database suitable for statistical purposes will be created based on the data. Internationally a two-year delay from diagnosis until publication of the statistics is considered to be adequate, as it enables also a comprehensive registration of first-line cancer treatments.
 
Accessibility and transparency of data
 
The statistics are published on the website of the Finnish Cancer Registry. A link to these data is also provided on the website of the National Institute for Health and Welfare. Data are also published in printed format in statistical publications of the Finnish Cancer Registry.
 
The National Institute for Health and Welfare may grant permission for researchers to use data of the Cancer Registry for scientific research purposes. For the permission to be granted, the researcher has to provide a register description and apply for a research-based authorization from the National Institute for Health and Welfare.
 
Comparability of statistics
 
The statistics for the years 1966–2010 each cover a period of 5 years, whereas the statistics for 2011 and 2012 are published as separate annual statistics. It is possible to compare the data by year, time series and area.
 
Since statistical year 2012, the data for the Åland Islands are not published separately on the website. However, the data for the Åland Islands are included in the rates of the specific catchment area of Turku University Central Hospital (TYKS-Erva).
 
Since 1953, cancer data have been collected in an electronic database of the Cancer Registry. A nationwide registration of cancers in Finland began in 1953, when the National Board of Health sent a circular to every doctor, hospital and laboratory in Finland, asking them to send a notification of all cancer cases that come to their attention and of all suspected cancer cases, to be included in cancer statistics. Since 1961, is has been compulsory to send notifications of cancer cases.
 
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 consistency
 
Well established international concepts and classifications are used in the statistical report. The topography (primary site; the part of the body where the cancer started) and morphology (histologic or cytologic diagnosis) of cancer cases will be coded according to the International Classification of Diseases (ICD-O-3). However, clinical ICD-10 codes are used in cancer statistics. Time and cause of death will be received from Statistic Finland's cause of death statistics. The data follows the norms of the cause of death classification officially set for the year in question. 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.
 
All forms and instructions related to cancer registration can be found on the website of the Finnish Cancer Registry at the following address http://www.cancer.fi/syoparekisteri/en/registration/.