1. Pennington Biomedical Research Center, Baton Rouge, LA, USA.
2. Merck Research Labs, Whitehouse Station, NJ, USA.
3. National Institute for Health and Welfare, Helsinki, Finland.
4. Oulu University and Unit of General Practice (Geriatrics), Oulu, Finland.
5. University of Helsinki, Helsinki, Finland.
6. South Ostrobothnia Central Hospital, Seinäjoki, Finland.
7. Hospital Universitario La Paz, Madrid, Spain.
8. Danube-University Krems, Krems, Austria.