1. Department of Medical Laboratory , Laboratory Medicine Institute, Instituto de Investigación Sanitaria Hospital Clínico San Carlos (IdISSC), Hospital Clínico San Carlos , Madrid , Spain
2. Complutense University of Madrid, Faculty of Medicine , Madrid , Spain
3. Research Methodological Support Unit , Instituto de Investigación Sanitaria Hospital Clínico San Carlos (IdISSC) , Hospital Clínico San Carlos , Madrid , Spain