Methodological Notes – Disease Incidence Module

Updated: January 2019

Concepts and Definitions

The occurrence of new cases of diseases, not all of which result in death, is another important dimension in the assessment of health in a population. CircHOB monitors the incidence of cancer and two infectious diseases – tuberculosis and gonorrhea.


Cancer is one of the few chronic, non-communicable diseases for which population-based registries have been in existence for decades, at least among the developed countries. Cancer registration is complex and requires an adequate health care infrastructure to maintain and sustain it. Registries differ in their comprehensive coverage of cases and the quality of the data captured. CircHOB reports age-standardized incidence rates (ASIR) of cancer, both for all cancers combined, and several more common sites, including lung, colon and rectum (the last two tend to be combined in some countries) in both sexes, prostate in men, and breast and cervix in women. A “case” refers to the anatomical site on which a new primary case occurs, and not from secondary spread from some other site. Only malignant cases (ICD-10 codes C00-C96) are reported – benign and in-situ neoplasms are excluded.

For age-standardization, a hypothetical standard population known as the “world standard population” is widely used in international comparisons of cancer incidence rates, developed by the International Agency for Research on Cancer (IARC) The age distribution in a population of 100000 people is as follows:

Age group Population
0-4 12,000
5-9 10,000
10-14 9,000
15-19 9,000
20-24 8,000
25-29 8,000
30-34 6,000
35-39 6,000
40-44 6,000
45-49 6,000
50-54 5,000
55-59 4,000
60-64 4,000
65-69 3,000
70-74 2,000
75-79 1,000
80-84 500
85+ 500
Total 100, 000

The “European standard population” is used by CircHOB to compare age-standardized mortality rates (ASMR) – see Methodological Notes: Mortality Module. The calculation for ASIR is the same as that for ASMR. The ASIRs can only be compared among themselves, or with any of the published rates in IARC or other scientific publications that use the same world standard population. They cannot be compared with published rates by some national agencies that use that country’s population from a specific year as the standard.

Infectious Diseases

Although the public health significance of infectious diseases has decreased substantially in recent decades, the overall burden of infectious diseases in the Arctic remains high, especially among the indigenous populations in some regions. Disease surveillance is an integral part of public health practice in the national and regional health care systems of circumpolar countries. Tuberculosis (TB) and gonorrhea are socially and epidemiologically important diseases which are reported consistently and regularly by all the regions. As both diseases are treatable and preventable, their incidence also reflects on the performance of the health system.

Infectious diseases are defined on the basis of their causative microorganisms, Mycobacterium tuberculosis for tuberculosis and Neisseria gonorrhœae for gonorrhea. There are operational case definitions used by public health agencies for the purpose of surveillance – see, for example, the ones used by the Centers for Disease Control and Prevention (CDC) of the United States

Inclusion and exclusion criteria vary across different jurisdictions, and in the absence of laboratory confirmation, cases defined on the basis of clinical signs and symptoms and other investigations (such as X-ray) may not be completely comparable internationally. CircHOB accepts as confirmed cases those that are reported by the various public health agencies.

The annual incidence rate of a disease = (number of new cases reported in Year X) / (mean population of year X)

This is usually expressed as the number of cases per 100, 000 persons. Crude rather than age-standardized rates are reported for TB and gonorrhea.

Data Sources and Limitations

United States

Data from the National Program of Cancer Registries are available from CDC Wonder Data from the CDC On-Line Tuberculosis Information System and Sexually Transmitted Disease Morbidity database are available from CDC Wonder.


Statistics Canada maintains the Canadian Cancer Registry. Age-sex specific data are available from Table 13-10-0111-01 (formerly CANSIM 103-0550) from which ASIR using the world standard population can be calculated for the national population. The practice of random rounding to 5 and 10 renders unusable data for the small populations of Yukon, Northwest Territories and Nunavut, where many age-sex categories have few cases. ASIRs for the territories are accessed from the branch research data centre located in ICHR in Yellowknife.

Infectious diseases data are extracted from Tuberculosis in Canada and Report on Sexually Transmitted Infections in Canada, various years, occasionally published by the Public Health Agency of Canada.


Cancer data are from NORDCAN

TB data are available from the annual report (Årsberetning) of the Chief Medical Officer (Landslægeembedet), various years Landslægeembedet -> Udgivelser -> Landslægeembedets Årsberetninger. Sexually transmitted diseases data are available from Statistics Greenland Health -> National Board -> STD (SUELSKS2)

Faroe Islands

Cancer data are from NORDCAN Infectious disease data are published in the annual report Sundhedsberetning of the Chief Medical Officer (Landslæknin í Føroyum) (2000-14 data are reported in the 2014 report).


Cancer data are from NORDCAN

The Directorate of Health provides an annually updated spreadsheet containing all notifiable communicable diseases


Cancer data are from NORDCAN Tuberculosis and gonorrhea data are available from the Statens Serum Institute >Smitteberedskab> Overvågning i tal, grafer og kort.


National data for cancer are from NORDCAN Regional data are available from the annual report Cancer in Norway

Both tuberculosis and gonorrhea are among the diseases listed in the Surveillance System for Communicable Diseases (Meldingssystem for smittsomme sykdommer, or MSIS) of the Norwegian Institute of Public Health (Folkehelseinstituttet)


National data for cancer are from NORDCAN Regional data are available from Socialstyrelsen’s statistical database

Tuberculosis and gonorrhea cases are reported by the Swedish Public Health Agency;

Data on pre 2007 gonorrhea cases and pre-2010 TB cases were retrieved from the former Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet), no longer archived.


National data for cancer are from NORDCAN

Regional data are from the Finnish Cancer Registry

Communicable disease surveillance is the responsibility of the National Institute of Health and Welfare (Terveyden ja hyvinvoinnin laitos, or THL), – data are available from the Finnish and Swedish websites only.

NORCAN, the Finnish Cancer Registry, and THL report regional data by hospital districts. For CircHOB, data for Pohjois-Suomi AVI (former Oulun lääni) are obtained by combining the hospital districts of Pohjois-Pohjanmaa and Kainuu, while those of Lappi are from the Lansi-Pohja and Lappi hospital districts.

Cancer data are available from the annual report Malignant neoplasms in Russia (incidence and mortality) (in Russian) published by the P.A. Hertzen Research Institute of Oncology in Moscow

TB and gonorrhea data are from a variety of Russian sources:

Only the Russian website of Rosstat contains the interactive database for regional data, which requires registration and login. Mednet also requires login.