In Sweden, there are many reliable data sources for register-based research. One reason is because Sweden maintains population-based registers with personal data.
Sweden has a system of unique personal identity numbers that allows researchers to link data from different registers to a specific individual. Registers of interest from a research point of view can be divided into national public authority registers, quality records in healthcare, biobanks and research-generated data.
National public authority registers
A large number of registers are available at various Swedish national public authorities that have been collected as part of the authorities’ activities. Of particular interest for research are population and socioeconomic registers, health registers and population-based surveys.
Most of the registers are available at Statistics Sweden (SCB) and the National Board of Health and Welfare.
For example, SCB keeps approximately thirty registers with personal data that are potentially interesting to researchers. Much of SCB’s data originate from other public authorities.
The National Board of Health and Welfare manages a series of registers relating to healthcare and social services that are widely used in research. A number of other authorities keep registers of population-based surveys and interviews, which have been conducted primarily for purposes other than research.
National quality registers
Quality registers are registers that have been created within specific areas of the healthcare system in order to develop and ensure the quality of care in a systematic and continuous way.
The registers contain personal data on healthcare in specific areas (examples of data are diagnosis, treatment, and treatment outcome). Today, the registers are used to improve and follow up healthcare outcomes as well as for research.
Kvalitetsregister.se provides a comprehensive account of the Swedish healthcare quality registers. The website has been developed by the office for National Quality Registers within the Swedish Association of Local Authorities and Regions (SKL). The office also provides support for cooperation with industry.
Research-generated data are individual data that researchers themselves have collected or otherwise compiled from different data collections. The higher education institutions are the principals of those registers that have been specifically created for research purposes.
The data in these registers have been collected to address certain specific research questions. After the project is completed, the data are destroyed or archived. Most registers created for research purposes are linked to special research projects. A complete list of these research-generated registers in Sweden is not available today, but many of them can be found at the Swedish National Data Service (SND).
There are also large research databases that can be considered as a kind of infrastructure, as they could be used in several different research projects.
About the Swedish National Data Service
SND is a service organisation for Swedish research in the humanities, social sciences and medicine, and is included as the Swedish node in an international network of data archives. SND makes it easier for researchers to access existing research-generated data within Sweden and abroad. The organisation also provides support and advice throughout the entire research process.
A biobank in itself is not a register but there are registers linked to the biobanks that contain information about samples and test providers, such as analysis results, diagnoses and questionnaire responses. A biobank may contain one or more sample collections, with samples taken as part of the healthcare activities or for a specific ethically approved research purpose.
In the health care system, numerous samples are taken daily, and some of them are stored in biobanks for healthcare purposes. However, these stored samples and the information associated therewith do not only have a significant impact on patient care but are also a prerequisite for developing healthcare through research on new knowledge about diagnostics, diagnosis classifications, improved treatments, new drugs and vaccines. Consent and ethics approval are required in order to use samples and associated information.
Types of biobanks
The most extensive biobanks are located within the county councils/regions, where over 90 percent of all biobanks are stored, especially within clinical pathology. The second largest healthcare activity involved in storing samples is clinical microbiology. The healthcare samples can be made available for research after ethics approval and by submitting the biobank application to the county/region’s biobanks.
In the county/region biobanks there are also collected samples that may be available to other researchers and research collaborations. Today, more than 150 million samples are stored in the healthcare biobanks, and approximately 3-4 million samples are added each year. There are also biobanks at universities and companies, where samples have been taken specifically for research and clinical trials, for example. Of these, a few are represented by the major biobanks structures, while most of them are individual research studies or virtual biobanks created for clinical drug trials where the samples are often handed out or destroyed immediately after analysis or sent abroad for analysis. Individual biobanks are also available at universities and government agencies, for example at the Swedish Food and Drug Administration. A total of approximately 450 biobanks are part of a register at the Health and Social Care Inspectorate (IVO), which is the supervisory authority for biobanks.