By 2060, the number of Europeans above age 65 is projected to increase from 88 to 153 million [1]. In consequence, the true challenge for European health care systems is to prepare for this monumental change in demography. Aging is closely related to the development of chronic diseases, which cumulate during life. This relatively recent phenomenon has given rise to the term multimorbidity (MM), defined as the presence of two or more chronic diseases at the same time in the same patient or a more recent and restricted definition the complex interactions of several co-existing diseases (https://www.ncbi.nlm.nih.gov/mesh/?term=Multimorbidity).
