Comparability

Comparability - geographical

For European comparable statistics in the field of substance abuse, please refer to the EUDA (European Union Drugs Agency), where the Danish Health and Medicines Authority participates and contributes data for Denmark.

Comparability over time

This statistic covers the period from 2015 onwards. Since the 2015 data did not undergo the same detailed quality control as the data from 2016 onwards, caution is advised when interpreting developments from 2015. Analyses of trends over time should only be conducted for municipalities that have approved their reporting and are included in the statistics for all years covered by the time series. For the years 2021–2025, all 98 municipalities are included, making comparisons across these five years possible. In 2015, 90 municipalities are included; in 2016, 91 municipalities; in 2017, 96 municipalities; and in 2018, 2019, and 2020, 97 municipalities are included. In connection with the release of the 2025 data, values for two municipalities for the years 2018, 2019, and 2020 have been imputed. Consequently, national totals for all years from 2018 to 2025 are published for the first time.

As a general rule, this statistic is comparable to the previous statistics from the Danish Social Authority’s (Socialstyrelsen) Drug Abuse Database, which was discontinued in 2017 when responsibility was transferred to Statistics Denmark. However, due to intensified follow-up with municipalities from 2017 onwards, coverage in the present statistics is likely higher than in the previous statistics. Therefore, comparisons over time should be made with caution. The underlying data for this statistic goes back to 1996, but comparisons over time should be made with caution due to extensive structural changes during the period. Following the Local Government Reform in 2007, responsibility for publicly funded drug abuse treatment was transferred from the counties to the municipalities.

On 1 September 2024, a new regionally based treatment service was introduced for citizens who have both a substance abuse problem and a psychiatric diagnosis. Regional data will be published separately from 2026 onwards, with the first release expected in August–September 2026. This may affect the comparability of municipal data over time, as the number of municipal drug treatment cases is expected to decline while the number of regional treatment cases increases. According to the plan, only individuals receiving psychiatric treatment and registered with a substance abuse diagnosis are included in the target group during the period from September 2024 to 30 June 2025. From 1 July 2025, the target group for regional dual-diagnosis treatment will be expanded to include individuals receiving treatment for both substance abuse and a mental disorder.

Three major data cleansing exercises have been carried out while Statistics Denmark has been responsible for the database:

• 1 July 2019: The entire ASI questionnaire was removed, and several questions in the Admission, Service, and KvalHep questionnaires were discontinued.
• 1 January 2024: From 1 January 2024, reporting of the Admission, Service, and Discharge questionnaires became voluntary, and from 1 January 2025 it is no longer possible to report them. As a result, reporting of these questionnaires after 1 January 2024 is incomplete and underestimated. Consequently, SMDB_IBIB is no longer published as Micro-data.
• 1 July 2025: The entire KvalHep questionnaire is discontinued, and several background variables (name, sex, citizenship, ethnic origin, education, housing situation) are removed or simplified.

Prior to the release of the 2023 data, an error occurred that resulted in overrepresentation in the variable “Other” for all years (2015–2023). This error has now been corrected.

Following the release of the 2023 data, Statistics Denmark became aware of an error in a municipal IT system that caused the incorrect registration of zero cases exceeding the treatment guarantee in some or all years during the period 2020–2023 for the municipalities of Greve, Lolland, Kerteminde, Langeland, Nordfyn, Nyborg, Odense, and Svendborg. This error has now been corrected.

Prior to the release of the 2024 data, the Municipality of Copenhagen informed Statistics Denmark that it had incorrectly registered 2,419 treatment service affiliations under the substance type “Other (medical) treatment provided under Section 142 of the Danish Health Act” instead of “Drug-free treatment provided under Section 101 of the Danish Social Services Act (or Section 33 of the Danish Children’s Act).” This error has now been corrected.

Reservations regarding comparisons between municipalities

Statistics Denmark is continuously engaged in dialogue with municipalities regarding correct reporting practices. During the validation of the 2025 data, we adopted a more systematic approach, including sending six specific validation questionsto all persons responsible for approval and upgrading our reporting website so that it now highlights the topics covered by these six questions. Guidance for reporting via the website has also been improved.

With the introduction of the Danish Children’s Act, which entered into force on 1 January 2024, children and young people in social drug abuse treatment received their own legal provision (Section 33). As a result, several municipalities became more aware of the reporting requirements for drug abuse treatment provided to persons under the age of 18. Persons under 18 who require drug abuse treatment may, in addition to Section 33, receive supportive interventions under Section 32. However, only persons referred under Section 33 are reported to the Drug Abuse Database. Whether a person is referred under Section 32 or Section 33 is determined through municipal case processing, and because municipal practices vary, inconsistencies may occur between municipalities regarding which individuals are reported to the Drug Abuse Database. Responsibility for reporting citizens above and below the age of 18 may be divided between two different municipal departments (the substance abuse department and the family/children and youth department). In some municipalities, prior to 2024, the family/children and youth department was unaware that it was responsible for reporting when referring persons under 18 to drug abuse treatment, until Statistics Denmark made them aware of this obligation. Trends in the data should be interpreted in light of this circumstance.

Statistics Denmark has also become aware that some municipalities are unaware that multiple treatment service affiliations can be registered within the same treatment episode. When changing treatment provider, some municipalities have closed the entire treatment episode and registered a new one. This results in an overestimation of requests, treatment initiations, and treatment completions. However, it is Statistics Denmark’s assessment that the vast majority of municipalities are aware of the correct reporting practice regarding changes in treatment provider.

Statistics Denmark has become aware that some municipalities only report treatment under Section 142 of the Health Act when a citizen receives treatment under both Section 142 of the Health Act and Section 101 of the Social Services Act. This reporting practice results in an underestimation of the number of citizens receiving treatment under Section 101.

Some municipalities fail to report treatment episodes that take place outside their own municipal substance abuse treatment centre.

In addition, some municipalities have not been aware that the treatment initiation date must be the actual date on which treatment begins. This affects the interpretation of compliance with the treatment guarantee. There have also been isolated cases where municipalities have recorded the request date and treatment initiation date as identical for all active treatment episodes. This gives a misleading picture of the municipality’s compliance with the treatment guarantee. Statistics Denmark is in dialogue with the relevant municipalities to correct these dates.

Coherence - cross domain

There is no direct connection with other statistics from Statistics Denmark.

Statistics users who are generally interested in drug abuse treatment for both drug abuse and alcohol can be referred to the National Alcohol Treatment Register (NAB) at the The Danish Health Data Authority.

Municipalities' services under Serviceloven are calculated across social statistics, i.a. adults (disability), vulnerable children and young people and drug abuse by Statistics Denmark. The sources for these statistics are often based on the municipalities' administrative IT-systems.

Coherence - internal

Data is consistent through a number of rules that ensure this. Consistency in the dataset is also ensured (see section "Forretningsregler" in the requirement specification).

In some tables tables, different definitions makes the number of persons differ marginally. E.g. a person who have moved from one municipality to another can be counted more than once in SMDBV002 but not in [SMDBV003](https://www.Statbank.dk/SMDBV003].