1. National Research and Development Centre for Welfare and Health, Health Services Research Unit, Helsinki, Finland, Nalional Public Health Institute, Department of Mental Health, Helsinki, Correspondence address: Anna-Mari Aalto National Research and Development Centre for Welfare and Health, Health Services Research Unit, P.O. Box 220, FIN-00531 Helsinki Finland Tel: +358-0-39672252...
2. National Public Health Institute, Department of Epidemiology and Health Promotion, Health Education Research Unit, Helsinki, Finland
3. National Research and Development Centre for Welfare and Health, Health Services Research Unit, Helsinki, Finland