Funding for this research was provided by:
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (33CS30-148415, 406740-139331)
Received: 2 March 2018
Accepted: 28 January 2019
First Online: 1 March 2019
Ethics approval and consent to participate
: Institutional ethics approval and consent were not required since all data are anonymized. Nevertheless, ethics approval for the record linkage of hospital, cause of death and census records was given by the ethics committee of the Canton of Zurich (Amendment to Stv-Nr. 13/06).
: Not applicable.
: The authors declare that they have no competing interests.
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