Advantages of linking national registries with twin registries for epidemiological research
AbstractLinking national registries with twin data represents an opportunity to produce epidemiological research of
high quality. National registries contain information on a broad array of variables, some of which cannot be
measured reliably in regular health surveys. By taking kinship into consideration, twin studies have the
benefit of being able to identify confounding stemming from genetic or shared environmental sources. In
this paper, we use examples from our own interview and questionnaire-based twin studies from the Norwegian
Twin Registry (NTR) on mental disorders, alcohol use and socioeconomic status linked to registry
data on medical benefits to demonstrate the value. In the first example, we examined to what extent genetic
and environmental factors contributed to sick leave and disability pension and the association between these
two types of benefits. In the second example, we explored the genetic and environmental relationship
between personality disorders and sick leave. In the third example, a co-twin control design was applied to
explore whether there is a true protective relationship between moderate alcohol consumption and health.
The fourth example shows to what degree anxiety and depression are associated with later sick leave granted
for not only mental disorders, but also somatic disorders, adjusted for confounding by genetic and shared
environmental factors. In the fifth example, we address the socioeconomic gradient in sick leave, adjusting
for non-observed confounders associated with the family in a co-twin control design. Our examples illustrate
some of the potentials obtainable by linking national registries with twin data. The efforts that have been
made to create the NTR in Norway and the International Network of Twin Studies (INTR) internationally
make these types of linkage studies easier to conduct and available to more researchers. As there are still
many areas to explore, we encourage epidemiological researchers to make use of this possibility.
Copyright (c) 2016 Line C. Gjerde, Fartein Ask Torvik, Kristian Amundsen Østby, Gun Peggy Knudsen, Nikolai Czajkowski, Ted Reichborn-Kjennerud, Ragnhild E. Ørstavik
This work is licensed under a Creative Commons Attribution 4.0 International License.
Norsk Epidemiologi licenses all content of the journal under a Creative Commons Attribution (CC-BY) licence. This means, among other things, that anyone is free to copy and distribute the content, as long as they give proper credit to the author(s) and the journal. For further information, see Creative Commons website for human readable or lawyer readable versions.
Authors who publish with this journal agree to the following terms:
1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
2. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
3. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).