1. Departments of Internal Medicine (R.P.P., H.v.T., W.K., Y.B.d.R., G.G.J.M.K., A.G.U., T.J.V.), Rotterdam, 3000 DR The Netherlands
2. Clinical Chemistry (Y.B.d.R., A.G.U.), Rotterdam, 3000 DR The Netherlands
3. Epidemiology and Biostatistics (A.G.U.), Erasmus University Medical Center, Rotterdam, 3000 DR The Netherlands