[1] Marques de Valdecilla Univ Hosp, Sandanter, Spain
[2] Univ Hosp Ramon y Cajal, Serv Prevent Med, Madrid, Spain
[3] Natl Distance Educ Univ UNED, Madrid, Spain
[4] Carlos III Inst Hlth, Madrid 28029, Spain
[5] Spanish Natl Res Council, Ctr Human & Social Sci, Madrid, Spain
[6] Carlos III Inst Hlth, CIEN Fdn, Alzheimer Dis Res Unit, Alzheimer Ctr Reina Sofia Fdn, Madrid 28029, Spain
[7] REDISSEC, Madrid, Spain