Accuracy and reliability

Overall accuracy

There is likely to be a minor degree of under-reporting, but there are no sources of systematic uncertainty. Data cannot be reported for persons without a valid social security number. Furthermore, municipalities that have entered into an agreement with other municipalities or drug abuse treatment centers to report on their behalf may be less aware of the quality of their data.

In the period from 11 April to 21 May 2023, Statistics Denmark experienced technical issues which resulted in the municipalities' figures not being updated daily as usual. Therefore, municipalities that have approved during this period will be registered with a fictitious approval date of 21 May 2023. Statistics Denmark has reviewed data for the affected municipalities and can ascertain that it has only had a very small impact on the municipalities involved.

Statistics Denmark has also become aware that many municipalities have not been aware that children and young people receiving drug abuse treatment must also be reported under § 101 i Serviceloven. Therefore, the number of children and young people under the age of 18 in the statistics has probably been underestimated, and a slight increase is expected in 2022 onwards, since several municipalities have become aware that children and young people under the age of 18 must be reported in this statistics. Statistics Denmark expect a further increase with the adoption of the Children's Act (Barnets Lov) (§ 33), which emphasizes the municipality's obligation to report drug abuse treatment for children and young people under the age of 18.

Statistics Denmark has also become aware that a few municipalities only report § 142 when they are dealing with a citizen who receives both drug addiction treatment under § 142 and § 101. This registration practice will result in an underestimation of the number of citizens in § 101 treatment.

Sampling error

Not relevant for these statistics.

Non-sampling error

In the drug abuse treatment statistics from Statistics Denmark, only the approved municipalities are included. In 2022, the statistics will thus cover the entire country, but in earlier years, not all municipalities are included in the statistics. Furthermore, only persons with a valid social security number are included in the statistics. This means that neither anonymous drug abuse treatments or foreigners who have not yet received a Danish social security number are included in the statistics.

Quality management

Statistics Denmark follows the recommendations on organisation and management of quality given in the Code of Practice for European Statistics (CoP) and the implementation guidelines given in the Quality Assurance Framework of the European Statistical System (QAF). A Working Group on Quality and a central quality assurance function have been established to continuously carry through control of products and processes.

Quality assurance

Statistics Denmark follows the principles in the Code of Practice for European Statistics (CoP) and uses the Quality Assurance Framework of the European Statistical System (QAF) for the implementation of the principles. This involves continuous decentralized and central control of products and processes based on documentation following international standards. The central quality assurance function reports to the Working Group on Quality. Reports include suggestions for improvement that are assessed, decided and subsequently implemented.

Quality assessment

The quality of the statistics is increasing every year, as work is continuously being done to find new ways to ensure the quality of data and to communicate better and more effectively with municipalities and drug abuse treatment centers.

Data revision - policy

Statistics Denmark revises published figures in accordance with the Revision Policy for Statistics Denmark. The common procedures and principles of the Revision Policy are for some statistics supplemented by a specific revision practice.

Data revision practice

Revisions for previous years are implemented when compiling results for a new year. Respondents can make corrections to already reported data or additions of new information daily. These changes will be included in the next publication. Each publication will make an estimate of the size of the revisions on the main figures distributed by municipalities. Relatively few revisions are expected for years that are more than a couple years back in time.