More information on health code sets
Last updated
Last updated
Inpatient Hilmo registry (INPAT) and Specialist outpatient Hilmo registry (OUTPAT), as well as the cause of death registry (DEATH), include ICD8/9/10, diagnosis codes, but ICD codes can also be found in the drug reimbursement (REIMB) and primary care (PRIM_OUT) registries. ICD codes used in the registries span three versions: ICD8 (years 1967-1986), ICD9 (years 1987-1995) and ICD10 (since 1996). In addition to diagnosis codes, the inpatient Hilmo and Specialized outpatient Hilmo registries contain operation/surgery codes; codes, Finnish hospital league surgery codes and demanding heart patient procedure codes. The cancer registry (CANC) contains ICD-O-3 cancer codes (topography, morphology and behaviour codes), whereas the PRIM_OUT registry contains cause of visit diagnosis codes (ICD/ICPC2), operation codes (SPAT), and dental codes (MOP)
Figure 1. Code sets within detailed longitudinal data.
Some of the code sets are Finnish specific (or Nordic specific) and not used anywhere else. Such code sets include
Drug reimbursement codes in REIMB registry
The Finnish hospital league surgery codes from the OPER_IN and OPER_OUT registries
Heart patient codes (new and old codes) from the OPER_IN and OPER_OUT registries
SPAT and Dental codes from the PRIM_OUT registry.
Nomesco operation codes (OPER_IN and OPER_OUT registry) are commonly used in northern countries (Nordic Medico-Statistical Committee)
In addition, many of the ICD and ATC codes are Finnish-specific.
Finnish versions of ICD-8/9/10, are not the same as the US clinical modification, nor the international WHO ICD (although the Finnish versions extend and modify the WHO versions).
The Death registry, however, uses only the WHO ICD and not any of the Finnish extensions.
Hereafter ICD refers to the Finnish versions unless otherwise stated. This is the reason why when using registry data it should always be remembered that Finnish codes do not match with, for example, international classification of the diseases (ICD10-CM). However, ICD-O-3 for cancer events follows the international version and consists of topography (TOPO), morphology (MORPHO) and behaviour (BEH) cancer codes.
It is also worth keeping in mind that ICPC2 (diagnosis codes) and SPAT (operation codes) from the primary care registry (PRIM_OUT) can be assigned by a nurse, whereas ICD codes are always assigned by a physician. This is a reason why one should consider whether to add PRIM_OUT registry codes to self-made endpoints.
Physicians can decide whether they prefer to use ICD or ICPC2 codes, and this preference may also change regionally in Finland.
Dental codes are part of Nomesco codes, where THL (The Finnish Institute for Health and Welfare) has made some extensions. The Nomesco coding has an indicator as to whether it's a dental (odontological) procedure code or not. PRIM_OUT codes have been piloted in FinnGen endpoint data; endpoints that have an ending “_INCLAVO” also contain PRIM_OUT codes.
The Kela drug purchase registry (PURCH) and Kela drug reimbursement registry (REIMB) consist of the following medical code sets: the ATC drug identifier code, drug reimbursement codes and drug product number VNR.
The Anatomical Therapeutic Chemical (ATC) codes are unique codes which are designated to drugs according to the targeted organ system and drug function (therapeutic, pharmacological, and chemical properties). This classification is highly curated and maintained by the World Health Organization (WHO).
The classification is broken down to 5 levels:
Level 1: A system of 14 anatomical or pharmacological groups (Figure 2)
Level 1 breakdown of the 14 anatomical and pharmacological groups (source: https://www.who.int/tools/atc-ddd-toolkit/atc-classification)
Level 2 Pharmacological or therapeutic groups
Level 3 and 4 Chemical, Pharmacological or Therapeutic subgroup
Level 5 Chemical substance
More appropriately, the 2nd, 3rd, and 4th levels are more often used to determine pharmacological subgroups than therapeutic or chemical subgroups.
As an example, Escitalopram (a commonly used Selective Serotonin Reuptake Inhibitor (SSRI) antidepressant) has an ATC code of N06AB10:
N06
Psychoanaleptics (2nd level, therapeutic group)
N06A
Antidepressants (3rd level, therapeutic group)
N06AB
Selective Serotonin Reuptake Inhibitors (SSRI) (4th level, therapeutic group)
N06AB10
Escitalopram (5th level, Chemical substance)
More information on ATC codes can be found here.
The VNR codes are Nordic country-specific codes known as the Nordic Article Number. These codes are used for the identification of specific drugs and medicinal articles which have been approved to be marketed in Nordic countries, including Finland.
The VNR codes are 6-digit codes ranging from 000001-199999 and 370000-599999.
They are assigned to all human medicines, veterinary medicines, herbal medicines, and traditional herbal medicines. Numbers outside of this range are called National Article Numbers which are used differently depending on the country
These codes are specific to how each of these drug/medicinal articles are marketed and can be then mapped to the article package size and dose. In the previous example (ATC code section) of using Escitalopram, a specific VNR code is keyed into the Kela drug registry when the drug article is purchased or reimbursed.
If person A purchased Escitalopram with VNR code X, code X will give you information on the number of pills and the dose of each pill in the article package that was purchased.
Note! Sometimes ATC-code of the medicine may have changed during the years. Here you can find all ATC alterations performed in the period 2005-2021.
Please see Location of translation file for register codes to find translations of the FinnGen register codes and Location of FinnGen endpoint description file to find out where the endpoint definition file is located.
