1. Institute of Clinical Medicine, General Practice, University of Turku, Lemminkäisenkatu 1, FIN-20520 Turku, Finland
2. Salo Health Center, Sairaalantie 9, FIN-20130 Salo, Finland
3. Central Laboratory, Turku University Central Hospital, Kiinamyllynk 4-8, FIN-20520 Turku, Finland
4. Härkätie Health Center, Hyvättyläntie 7, FIN-21420 Lieto, Finland
5. The Social Insurance Institution, Research and Development Centre, Peltolantie 3, FIN-20720 Turku, Finland
6. Satakunta Central Hospital, Sairaalatie 3, FIN-28500 Pori, Finland