The case for a global focus on multiple chronic conditions

### Summary box One in three adults globally suffers from multiple chronic conditions (MCC).1 This figure is closer to three out of four in older adults living in developed countries1 and is predicted to rise dramatically, with the proportion of patients with four or more diseases almost doubling between 2015 and 2035 in the UK.2 Yet the response from the health community is non-commensurate. In our 2017 overview of the burden from MCCs, presented at a World Economic Forum event in September 2017 alongside the United Nations General Assembly, we concluded that despite MCCs being so prevalent, there is a dearth of information on their prevalence, clustering, cost and patient burden.3 A 2018 systematic review published in BMJ Global Health by Sum et al aimed to quantify out-of-pocket expenditure (OOPE) on medicines in patients with MCCs.4 Using the context of the findings from Sum et al , we argue why MCCs warrant specific focus by the health community. Challenges persist in framing the topic of MCCs. First, there is no agreed taxonomy. Our research found that several terms including MCCs, multimorbidity, comorbidity and polychronic diseases are all used interchangeably to mean ‘more than one chronic condition’.3 However, experts deemed …