1. Department of Medicine, Kuopio University Hospital, Kuopio, Finland
2. Institute of Diagnostics, Medical Microbiology and Immunology, Research Unit of Biomedicine, Oulu, Finland
3. University of Oulu and Medical Research Center and Nordlab Oulu, Oulu University Hospital, Oulu, Finland
4. Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland
5. Unit of Primary Health Care, Kuopio University Hospital, Kuopio, Finland
6. Unit of Family Practice, Central Finland Central Hospital, Jyväskylä, Finland
7. Department of Medicine, Iisalmi Hospital, Iisalmi, Finland
8. Department of Medicine, Varkaus Hospital, Varkaus, Finland
9. Outpatient Department, Suonenjoki Health Centre, Suonenjoki, Finland