Citation

Smith Jervelund S, De Montgomery CJ. Scand. J. Public Health 2020; 48(1): 1-4.

Affiliation

Faculty of Health and Medical Sciences, Department of Public Health, University of Copenhagen, Denmark.

Copyright

(Copyright © 2020, Associations of Public Health in the Nordic Countries Regions, Publisher SAGE Publishing)

DOI

10.1177/1403494819898573

PMID

31985364

Abstract

The Nordic countries’ national registries allow for the creation of large cohort studies that are impossible in most other countries. This is realizable due to the existence of a wide range of government-maintained nationwide public registries, containing individual-level data collected routinely for administrative purposes that touch on most facets of our lives, including health. These registries can be linked through a common key, the unique personal identification number assigned to all residents in the Nordic countries since the establishment of national civil registry systems between 1964–1969 [1]. The personal identification number makes it possible to link individual-level data from different registries, allowing for a lifelong follow-up time. Although linking and analysing such data in many countries would be considered infringement on rights to privacy and personal ownership of data, the Nordic region is characterized by high levels of trust towards public institutions [2], manifest in a general public expectation, encoded in law, that information gathered administratively is used to produce new knowledge of social value [3]. This makes it possible to analyse an entire country as an open cohort, censored only by death and emigration [4]. Often compared to a gold mine, the atmosphere surrounding the use of this data certainly compares to that of a gold rush. Quoting Schmidt et al., ‘the possibility of exact individual-level data linkage provides unlimited possibilities for epidemiological research’ [5]. Indeed, the major advantages created by this data for epidemiological and other types of research in the Nordic countries has already proved itself and there is no reason to dismiss the promises held by this research to benefit public health worldwide.

At the same time, the complex and varied processes of data collection, processing and quality controls underpinning registry data calls for detailed attention to their validity and completeness. As shifting administrative procedures and priorities can have large impacts on the data we analyse, the interpretation of our findings hinges on our familiarity with the details of data production. In addition, registry data are not immune to errors and misclassification and validation studies of specific registries are crucial to assess the accuracy of information. Being awake to the possibilities of registry data, a stable feature of the conversation within our research community must be to delve deeper into these issues ...

Language: en