1. Department of Nuclear Medicine; Odense University Hospital; Sdr. Boulevard 29 5000 Odense C Denmark
2. Department of Business and Economics; Centre of Health Economics Research, University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
3. Institute of Clinical Research; University of Southern Denmark; Winsløwsparken 19 5000 Odense C Denmark
4. Clinical Epidemiology; Department of Medical Biometry and Medical Informatics, University of Freiburg; Stefan-Meier-Str. 26 79104 Freiburg Germany