Multimorbidity in people with type 2 diabetes in the Basque Country (Spain): Prevalence, comorbidity clusters and comparison with other chronic patients

Background: Multimorbidity is a common problem in ageing societies and has a wide range of individual and social consequences. The objective of this study was to compare multimorbidity in a population with type 2 diabetes (T2DM) with that in other chronic patients, and identify disease clusters in patients with T2DM.

Methods: We included all citizens in the Basque Health Service aged ≥ 35 years, and identified the population with chronic conditions (from a list of 51 diseases) and those with T2DM. We performed a descriptive analysis of both populations, including their comorbidities. The average of chronic conditions unadjusted and adjusted by socioeconomic variables was obtained. Further, among patients with T2DM, we performed agglomerative hierarchical clustering to identify clinically relevant subgroups with the same concurrent conditions.

Results: In 2011, out of a population of 1,473,937, 15.2% had T2DM and 48% some other type of chronic condition. Overall, 87.6% men and 92% of women with T2DM had multimorbidity, while the figures were respectively 54.2% and 57% in chronic patients without T2DM. Patients with T2DM had a higher risk than the general chronic population of having 21 of the 51 chronic conditions considered. We identified 10 relevant disease clusters in patients with T2DM.

Conclusions: There are notable differences between chronic patients with and without T2DM, the prevalence of multimorbidity being greater among the former. Multimorbidity is a complex phenomenon and more research is required to establish the clinical implications of the disease clusters found, to guide the introduction of integrated care management programmes.