The number of people with multimorbidity is high and increases with age, affecting more than 60% of people aged 65+ in Belgium. Multimorbidity is associated with numerous negative consequences, including mortality, disability and poor quality of life. It has also a major impact on health care use and the associated costs. Multimorbidity occurs more often among socially disadvantaged population groups, and thus failure to provide appropriate care for multimorbid patients is likely to also have a negative effect on equity in health care.

Although multimorbid patients have complex health needs, the current focus is still too much on traditional disease-oriented approaches. Consequently, multimorbid patients often receive fragmented care, leading to inefficient, ineffective, and possibly harmful clinical interventions. They often receive complex drug regimens, which increase the risk of inappropriate prescription, drug-drug interactions, adverse drug reactions and poor adherence to medications. In addition, compared to persons with one chronic disease, multimorbid patients more often have problems related to mobility, self-care, day-to-day functioning, quality of life, and they also have more pain and cognitive problems, which makes care and treatment challenging.

Multimorbidity challenges the “single-disease” viewpoint currently assumed in health care, prescription behaviour, medical research and medical education. Models of care for patients with multimorbidity will have to focus on the idea of ‘treating people, not disease’.  This will require a more coordinated approach between different health professionals, also taking into account social needs.