Statistical processing

Source data

External sources: The National Patient Registry, provided by the Danish Health Data Authority. The National Patient Registry contains information on all contacts with Danish public and/or private somatic and psychiatric hospitals. From 2012 to 2015, data from the National Patient Registry were provided by the Statens Serum Institut, and prior to 2012, by the Danish Health Authority. LPR3 data are available for the years 2019–2024, and the annual (LPR3) data delivery was resumed in 2022. LPR2 data were received annually until 2019.

Internal sources:

• The register of population statistics (municipality and ancestry)
• The Employment Classification Module (labour market affiliation (SOCIO13))
• The Education Register (highest completed level of education)
• The Relatives Register (relatives, partner)

Frequency of data collection

Annually.

Data collection

Extracts from the master tables of the National Patient Register in the Danish Health Data Agency are transmitted via a secure connection to Statistics Denmark.

Data validation

The Danish Health Data Agency is responsible for the operation and validation of the National Patient Register. Go to the Danish Health Data Agency for more information. (Link in Danish)

Data compilation

In compiling the statistics, information from several registers are combined. The LPR table named “Hospital stays” is supplemented with a variable (the primary diagnosis linked to the last contact of the stay) from the LPR table named “Contacts.” In addition, variables are added from the Population Statistics Register (municipality of residence, ancestry), the Employment Classification Module (SOCIO13), the Education Register (highest completed education), and the Relatives Register (partner, other relatives).

Age is calculated at the end of the year based on the date of birth, which is determined during the pseudonymisation of LPR data. Persons over 115 years of age are excluded. Municipality of residence is taken as of year-end, labour market attachment as of 31 December of the previous year, and highest completed education as of 30 September of the previous year.

Diagnosis (the primary diagnosis linked to the last contact of the stay) is grouped into main diagnosis groups according to the Danish version of the WHO’s 21 ICD-10 (International Classification of Diseases) groups, see the SKS browser. Certain diagnoses that cannot be placed within these groups are assigned manually.

The number of stays is also calculated by type of hospital, type of hospital service, and length of stay (under/over 12 hours). Finally, the data are compiled into two datasets: one with one observation per stay and one with one observation per person. The latter is created by removing duplicates from the former.

Adjustment

Not relevant for these statistics