Use of Linked Nordic Registries for Population Studies in Hematologic Cancers: The Case of Multiple Myeloma

Niels Abildgaard,1,2 Jonatan Freilich,3,4 Pekka Anttila,5 Nawal Bent-Ennakhil,6 Yuanjun Ma,3 Mariann Lassenius,7 Sigurd Ørstavik,8 Iiro Toppila,7 Anders Waage,9 Ingemar Turesson,10 Markus Hansson11 1Hematology Research Unit, Department of Hematology, Odense University Hospital, Odense, Denmark; 2Department of Clinical Research, University of Southern Denmark, Odense, Denmark; 3Department of Access Consulting, PAREXEL International, Stockholm, Sweden; 4Department of Public Health and Clinical Medicine, Dermatology, Umeå University, Umeå, Sweden; 5Comprehensive Cancer Center, Department of Hematology, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland; 6Takeda Pharmaceuticals International AG, Zurich, Switzerland; 7Medaffcon, Espoo, Finland; 8Takeda Pharmaceuticals International AG, Oslo, Norway; 9Department of Hematology, St Olav’s University Hospital, Trondheim, Norway; 10Lund University Cancer Centre, University of Lund, Skåne University Hospital, Lund, Sweden; 11Sahlgrenska Academy and Sahlgrenska University Hospital, Göteborg, SwedenCorrespondence: Niels Abildgaard, Department of Hematology, Odense University Hospital, Kloevervaenget 10, Floor 12, 5000 Odense C, Denmark, Tel +45 6541 1155, Email niels.abildgaard@rsyd.dkPurpose: Linked health-care registries and high coverage in Nordic countries lend themselves well to epidemiologic research. Given its relatively high incidence in Western Europe, complexity in diagnosis, and challenges in registration, multiple myeloma (MM) was selected to compare registries in Denmark, Finland, and Sweden.Patients and Methods: Data were obtained from four archetypal registries in each country (spanning January 2005–October 2018): National Patient Registry (NPR), Prescribed Drug Registry (PDR), Cancer Registry (CR), and Cause of Death Registry. Patients newly diagnosed with MM who received MM-specific treatment were included. PDR/NPR treatment records were used to assess incident NPR cases. The re