Accuracy and reliability

Overall accuracy

The reliability of the statistics on imprisonments is considered to be good. The data on imprisonments come from a single administrative register and Statistics Denmark receives a single total extract including all imprisonments in Denmark. The statistics include all imprisonments registered in the central criminal register at the time the extract to Statistics Denmark is done, typically about 1 February following the relevant calendar year. A number of imprisonments started/ended during the calendar year have not been registered before the time of extraction. This implies that the total number of imprisonments presumably is under-estimated. The exact size is not known but is regarded as limited and of the same extent each year.

Sampling error

There is no sampling error as the statistics are compiled on the basis of registers.

Non-sampling error

The statistics include all imprisonments which have been registered in the central criminal register at the time the extract to Statistics Denmark is done, typically about 1 February following the relevant calendar year. A number of imprisonments started/ended during the calendar year, may not be included in the statistics, since not all imprisonments have been registered before the time of extraction. That implies that the total number of imprisonments presumably is under-estimated. The exact size is not known but is regarded as limited and of the same extent each year.

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 data on imprisonments come from a single administrative register and Statistics Denmark receives a single total extract including all imprisonments in Denmark. The statistics include all imprisonments registered in the central criminal register at the time the extract to Statistics Denmark is done, typically about 1 February following the relevant calendar year. A number of imprisonments started/ended during the calendar year have not necessarily been registered before the time of extraction. This implies that the total number of imprisonments presumably is under-estimated. The exact size is not known but is regarded as limited and of the same extent each year.

Police activity such as speed controls or special efforts in the night life can in itself affect the number of imprisonments. Therefore, one need to take this into account when studying the development in the number of imprisonments for violation of the road traffic act and other special laws such as police regulation and euphoriants act.

The statistics are only published as final figures and are not later revised.

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

Only final figures are published and are not later revised.