1. Department of Clinical Neuroscience and Family Medicine, Division of Family Medicine, Karolinska Institute, Stockholm, Correspondence address: Per Wandell Dept of Family Medicine Novum SE-14157 Huddinge Sweden
2. The Swedish Council on Technology Assessment in Health Care, P.O. Box 16158, S-103 24 Stockholm, Sweden
3. Department of Clinical Neuroscience and Family Medicine, Division of Family Medicine, Karolinska Institute, Stockholm