provided to all Danish
residents. The data were obtained from the Central
Population Registry, the National Patient Registry,
the Registry of Medicinal Product Statistics, the
National Registry on Regular Dialysis and Transplantation,
and the National Registry of Causes of
Death.17-22 The details of the information contained
in each of these registries, as well as the diagnoses,
surgical procedures, and pharmacotherapy used for
defining the study population, coexisting conditions,
and outcomes, are provided in the Supplementary
Appendix, available with the full text of
this article at NEJM.org.