1. Institute of Medicine, Department of Molecular and Clinical Medicine, University of Gothenburg , Gothenburg , Sweden
2. Department of Cardiology, Sahlgrenska University Hospital , Gothenburg , Sweden
3. Department of Clinical Sciences Lund, Anesthesiology and Intensive care, Lund University, Helsingborg Hospital , Lund , Sweden
4. Department of Clinical Science and Education, Södersjukhuset, Centre for Resuscitation Science, Karolinska Institutet , Stockholm , Sweden
5. Centre for Clinical Research Dalarna, Uppsala University , Falun , Sweden
6. Department of Clinical Sciences Lund, Anesthesiology and Intensive care, Lund University , Lund , Sweden
7. Prehospen—Centre for Prehospital Research, University of Borås , Borås , Sweden
8. The Swedish Registry for Cardiopulmonary Resuscitation, Centre of Registries , Västra Götaland , Sweden