0 Administrative Information about the Statistical Product


0.1 Name
Hospitalization

0.2 Subject Area
Social conditions, health and justice

0.3 Responsible Authority, Office, Person, etc.
Population
Lisbeth Laursen, tel. +45 39 17 31 03, e-mail: lil@dst.dk

0.4 Purpose and History
The purpose of the statistics on hospitalization is to contribute to a description of the relationship between social conditions and admissions to hospitals. 1990 is the first year covered by the statistics. Since then the content of the statistics has continuously been extended. E.g. in 1994 the statistics was supplemented with a number of new variables to describe the social conditions at family level.

0.5 Users and Application
Users
Municipalities
Counties
Ministries
Organizations
Private enterprises
Private individuals

Application
Public planning purposes
Research
Public debate

0.6 Sources

• National Register of Patients operated by the National Board of Health and following registers operated by Statistics Denmark:
• The Population Statistics Register, see the following declaration of contents under the subject Population and elections: The population 1. January, Household and family statistics and Immigrants and their descendants
• The Medical Register of Births and Deaths (up to and including 2005), see the declaration of contents for Medical birth and death statistics under the subject Population and elections
• The Central Register of Buildings and Dwellings, se the declaration of contents for Census of Housing under the subject Construction and housing
• The Educational Classification Module, see the declaration of contents for Education of the population under the subject education and culture
• The Employment Classification Module
• The Register of Prosperity Statistics, see the declaration of contents for Family Income Statistics under the subject Income, consumption and prices
• The Register of Health Insurance Statistics (up to and including 2005), see the declaration of contents for Health Insurance Statistics under the subject Social conditions, health and justice
• The Register of Transfer Payments, see the declaration of contents for Coherent Social Statistics under the subject Social conditions, health and justice

0.7 Legal Authority to Collect Data
The information is collected in accordance with the Act on Statistics Denmark (Lov om Danmarks Statistik), Section 6, cf. Order no. 599 of 22 June 2000.

0.8 Response burden
There is no response burden as the data are collected by the National Health Board and other public authorities.

0.9 EU Regulation
No EU regulation.


1 Contents


1.1 Description of Contents
The statistics cover admissions to somatic hospital departments within one calendar year. The statistics deal with the number of admissions, the number of bed days and the most important diagnosis. Furthermore, the statistics show how the use of hospitals varies with a range of social conditions, such as family, education, occupation, income, etc.

1.2 Statistical Concepts
The population of the statistics is admissions to stationary somatic hospital departments within one calendar year.

If a person during a stay in hospital is moved from one department to another it will count as two admissions.

The statistical units are admitted people, admissions and bed days.

In the statistics the concept admission rate is used. It is defined as the part of a specific population group, which has been admitted during the year. The use of hospital varies highly with age. Therefore, in some of the statistics, an age standardisation has been effected. As from 2000 standardisation for socio-economic status concerning the adults and for the family's level of education concerning the children has furthermore been effected.

The statistics are distributed by sex, age, diagnosis, region and a number of background variables: type of family, occupation, job function, education, social benefit, type of dwelling and origin.

For every person who has been resident in Denmark during the calendar year the register stores the following information regarding the person's use of hospitals:

• Number of admissions and number of bed days within four different causes of hospitalization: Own sickness, Relatives accompanying relatives (left out as from 2002), Pregnancy/delivery and Symptoms, signs and ill-defined conditions
• Dominating diagnosis (the diagnosis for which most bed days in hospitals was recorded) according to groups in the classification of diagnoses: 23 grouping (up to and including 2005) and the S-list. The two groupings are Danish short-lists of WHO's International Classification of diseases, version 10.

The contents of the S-list (also called the 99-grouping) can be found by using the link in the note to tables UD11, UD33A,
PA11 and PA11A in StatBank Denmark, cf. item 5.1.

• Total number of different diagnoses according the S-list (up to and including 2005).
• Number of bed days with the dominating diagnosis according to the 23 grouping (up to and including 2005) and the S-list
• Information on whether the person has been admitted or not within the latest 4 years, and if so, with which cause(s) of hospitalization (up to and including 2005).

For every admission during the calendar year the register stores information on:

• Code for hospital and hospital department to which the admission took place (up to and including 2005)
• Dates of admission and discharge
• Type of hospitalization (emergency or non-emergency)
• Code for cause of admission, that is sickness, accident, violence etc.(up to and including 2005)
• In cases where the admission is caused by an accident the register contains information on the circumstances under which the accident happened (up to and including 2005)
• Main diagnosis grouped according to the 23 grouping and the S-list
• Duration of the admission

Number of days in relation to any previous admission in the calendar year (up to and including 2005).


2 Time


2.1 Reference Period
The reference period is the calendar year in which the admission took place.

2.2 Date of Publication
The statistics are produced yearly.

The statistics are published in News from Statistics Denmark 4-5 weeks and in Statistical News about 2 months after Statistics Denmark has received the necessary information form the National Board of Health. The time of delivery of the data from the National Board has varied during the years. This has implied that the statistics have been published between 1 and 1½ year after the end of the reference period.

2.3 Punctuality
The statistics are usually published without delay in relation to the scheduled date.

2.4 Frequency
The statistics are published yearly.


3 Accuracy


3.1 Overall accuracy
The National Board of Health validates the National Register of Patients and the reliability of the data in the register is in general regarded as high.

In 1990 an evaluation of the quality of the data in the National Register of Patients was carried out. The result of this evaluation was that the administrative information (e.g. dates) had a high level of reliability while the medical data (e.g. diagnoses) had a lower level of reliability. However, as Statistics Denmark uses the codes of diagnoses at an aggregated level this is not assessed to be of major importance.

For an assessment of the reliability of the other registers of persons statistics, which are operated by Statistics Denmark and used in the statistics on hospitalization, reference is made to the specific declarations of contents of these registers.

3.2 Sources of inaccuracy
Coverage
The National Register of Patients is set up on the basis of reports from the specific hospital departments. Data concerning an admission has to be recorded when the admission ends. It is assessed that this happens close to 100 percent of all cases.

Collection/measuring
The National Register of Patients is an administrative register and Statistics Denmark receives one extract yearly.

Processing of data
Statistics Denmark carries out a validation/probability check of the extract from the National Register of Patients. In case errors are detected the National Board of Health is contacted for clarification

3.3 Measures on accuracy
There are no sampling errors as the statistics are compiled on the basis of a census.


4 Comparability


4.1 Comparability over Time
The same primary data have been used since 1990 when the statistics were compiled for the first time.

On 1 January 1994 the new International Classification of Diseases (ICD10) was introduced. This replaced the former ICD8-classification. This implies that caution has to be exercised in comparing the disease pattern before and after 1 January 1994.

Furthermore, the development in the disease pattern can be influenced by changes in the practice of recording. For instance, there has been a considerable increase in the number of admissions with diagnoses in the group Symptoms, signs and ill-defined conditions. This is due to an increasing tendency to record symptoms in stead of a specific disease as long as the disease is not clearly defined.

The information in the National Register of Patients on admissions caused by road traffic accidents is up to and including 1994 regarded as defective. Since 1995 the information is regarded as adequate.

When looking at the use of hospitals in 1995 the trade dispute among hospital nurses this year has to be taken into consideration.

The use of the background information in the statistics has continuously been extended, cf. item. 0.4. Consequently, some of the statistics cannot be found for all years.

4.2 Comparability with other Statistics
The National Board of Health issues yearly statistics about the activity at hospitals. These statistics are also based on the information in the National Register of Patients. The statistics on the population's use of hospitals are comparable with these statistics, except the definition of the group of people covered by the statistics: In most of the tabulations the statistics on the population's use of hospitals only cover people living in Denmark as of 1 January in the specific year. This implies that people who were born or immigrated to Denmark during the year are not covered by the statistics. Another difference is that the statistics in the population's use of hospital assign people according to their municipality/county as of 1 January in the specific year, while the statistics from the National Board of Health assign people according to their municipality/county as of the date of admission.

4.3 Coherence between provisional and final statistics
Only final figures are published.


5 Accessibility


5.1 Forms of dissemination
The statistics are published in Nyt fra Danmarks Statistik (News from Statistics Denmark),
in Sociale forhold, sundhed og retsvæsen (Social conditions, health and justice) appearing in the series Statistical News. The latest published issue is 2008:10, 25th June 2008 with the title "Hospitalization 2006". Only in Danish.
Yearly publications: Statistical Yearbook.
Statbank Denmark: www.statistikbanken.dk:
Social conditions, health and justice, Hospitalizations: UD11, UD22, UD33, UD33A
Social conditions, health and justice, Hospital patients: PA11, PA11A, PA6, PA7, PA8, PA9.

5.2 Basic material: Storage and usability
The Register of Hospitalization stores complete data on the population's use of hospitals at the level of individuals. Furthermore, complete data on all admissions at the level of individuals are stored. This information can be used in compiling other or more detailed statistics than those published.

5.3 Documentation
The primary data and the content of the statistics are described in Statistical News.

The content of the Register of Hospitalization is documented in Statistics Denmark's documentation system (TIMES).

5.4 Other Information
Other information is not available.


Supplementary documentation
No supplementary documentation is available