Multimorbidity is a major challenge for healthcare systems. However, currently, its magnitude and impact in healthcare expenditures is still mostly unknown. To present an overview of the prevalence and costs of multimorbidity by socioeconomic levels in the whole Basque population. We develop a cross-sectional analysis that includes all the inhabitants of the Basque Country (N = 2,262,698). We utilize data from primary health care electronic medical records, hospital admissions, and outpatient care databases, corresponding to a 4 year period. Multimorbidity was defined as the presence of two or more chronic diseases out of a list of 52 of the most important and common chronic conditions given in the literature. We also use socioeconomic and demographic variables such as age, sex, individual healthcare cost, and deprivation level. Predicted adjusted costs were obtained by log-gamma regression models. Multimorbidity of chronic diseases was found among 23.61% of the total Basque population and among 66.13% of those older than 65 years. Multimorbid patients account for 63.55% of total healthcare expenditures. Prevalence of multimorbidity is higher in the most deprived areas for all age and sex groups. The annual cost of healthcare per patient generated for any chronic disease depends on the number of coexisting comorbidities, and varies from 637 € for the first pathology in average to 1,657 € for the ninth one. Multimorbidity is very common for the Basque population and its prevalence rises in age, and unfavourable socioeconomic environment. The costs of care for chronic patients with several conditions cannot be described as the sum of their individual pathologies in average. They usually increase dramatically according to the number of comorbidities. Given the ageing population, multimorbidity and its consequences should be taken into account in healthcare policy, the organization of care and medical research.

Understanding the quality, costs and outcomes of healthcare services requires precise determination of the morbidity in a population. Measurement of morbidity in a population and its association with the services provided remains to be performed. The aim of this article was to present our experience of using clinical risk groups (CRGs) to measure morbidity in an integrated healthcare organization (IHO). We studied the population attended by an IHO in a county (approximately 120,000 patients) from 2002 to 2005. CRGs were used to measure morbidity. A descriptive analysis was performed of the population's distribution in CRG categories and utilization rates. One or more chronic diseases was found in 15.5% of the population, significant acute illness was found in 9%, minor chronic diseases was found in 7% and very severe diseases was found in 0.5%. Between 2002 and 2005, the number of individuals with chronic disease increased by 8%. The burden of illness increased with age. However, at all ages, at least 40% of the population remained healthy. Comorbidity in chronic illnesses was a crucial factor in explaining healthcare resource utilization. The CRG grouping system aids analysis at different levels for clinical administration. Due to its composition, this system allows better understanding of the use, costs and quality of the set of services received by a population.

Patients with multimorbidity are responsible for more than half of all healthcare utilization, challenging the healthcare budgets of all European nations. Although the European Union is showing signs of a fragile economic recovery, achieving sustainable growth will depend on delivering a combination of fiscal responsibility, structural reforms, and improved efficiency. Addressing the challenges of multimorbidity and providing more effective, affordable, and sustainable care, has climbed the political agenda at a global, European, and national level. Current healthcare systems are poorly adapted to cope with the challenges of patients with multimorbidity. Little is known about the epidemiology and natural history of multimorbidity; the evidence base is weak; clinical guidelines are not always relevant to this population; and financing and delivery systems have not evolved to adequately measure and reward quality and performance. Pockets of innovation are, however, beginning to emerge. In Spain, for example, the ongoing economic crisis has forced regional governments to deliver substantial efficiency savings and, with this in mind, integrated care programmes have been introduced across the country for people with chronic disease and multimorbidity. Early results suggest that formalized integrated care for patients with multimorbidity improves their perceptions of care coordination, reduces hospital and emergency admissions and readmissions, and reduces average costs per capita. Such innovations require meaningful investments at a national level – something that is now supported within the framework of the European Union's Stability and Growth Pact.