1. Department of General Practice and Primary Health Care, Faculty of Medicine, University of Helsinki, Finland;
2. Department of Public Health, Faculty of Medicine, University of Helsinki, Finland;
3. Health Care and Social Services, City of Vantaa, Finland;
4. Attendo LDT, Helsinki, Finland;
5. Oy Apotti Ab, Helsinki, Finland;
6. HUSLAB Laboratory Services, Helsinki University Hospital, Helsinki, Finland;
7. Helsinki University Hospital, Unit of Primary Health Care, Helsinki, Finland