1. Olli-Pekka Ryynänen, University of Kuopio, Public Health Research Institute and Department of Community Medicine and General Practice, Kuopio, Finland, Address for correspondence: Olli-Pekka Ryynänen Department of Community Medicine and General Practice P.O. Box 1627 SF-70211 Kuopio Finland
2. Sirkka-Liisa Kivelä, University of Oulu, Department of Public Health Science and General Practice Oulu, Finland
3. Risto Honkanen, University of Kuopio, Public Health Research Institute and Department of Community Medicine and General Practice, Kuopio, Finland
4. Pekka Laippala, University of Tampere, Department of Public Health Science, Tampere, Finland
5. Veijo Saano, University of Kuopio, Department of Pharmacology and Toxicology Kuopio, Finland