title: Multimorbidity in people with type 2 diabetes in the Basque Country (Spain): Prevalence, comorbidity clusters and comparison with other chronic patients.
abstract: 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.
authors.affiliation: O+berri (Basque Institute for Healthcare Innovation), Torre del BEC (Bilbao Exhibition Centre), Ronda de Azkue 1, 48902 Barakaldo, Spain. Electronic address: edurne.almo@gmail.com.
authors.forename: Edurne
authors.initials: E
authors.lastname: Alonso-Morán
authors.affiliation: Osakidetza (Basque Health Service), Astrabudua Health Centre, Mezo 35, 48950 Erandio, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Orueta
authors.affiliation: Osakidetza (Basque Health Service), San Miguel Health Centre, Garbileku s/n, 48970 Basauri, Spain.
authors.forename: Jose Ignacio Fraile
authors.initials: JI
authors.lastname: Esteban
authors.affiliation: Department of Health, Donostia-San Sebastián 1, 01010 Vitoria-Gasteiz, Spain.
authors.forename: José Ma Arteagoitia
authors.initials: JM
authors.lastname: Axpe
authors.affiliation: Osakidetza (Basque Health Service), Uribe Area, Alango 30, 48992 Getxo, Spain.
authors.forename: Ma Luz Marqués
authors.initials: ML
authors.lastname: González
authors.affiliation: World Health Organization, Services Organization and Clinical Interventions Unit, Avenue Appia 20, CH-1211 Geneva, Switzerland.
authors.forename: Nuria Toro
authors.initials: NT
authors.lastname: Polanco
authors.affiliation: Osakidetza (Basque Health Service), Zumaia Health Centre, Basadi 15, 20750 Zumaia, Spain.
authors.forename: Patxi Ezkurra
authors.initials: PE
authors.lastname: Loiola
authors.affiliation: Endocrinology and Nutrition Department, Osakidetza (Basque Health Service), Cruces University Hospital, Plaza de Cruces s/n, 48903 Barakaldo, Spain; The University of the Basque Country, Leioa, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Gaztambide
authors.affiliation: O+berri (Basque Institute for Healthcare Innovation), Torre del BEC (Bilbao Exhibition Centre), Ronda de Azkue 1, 48902 Barakaldo, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Nuño-Solinís
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000453:epidemiology*; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010346:Patient Care Management; D012044:Regression Analysis; D017678:Sex Distribution; D013030:Spain / Q000453:epidemiology
keywords: Chronic conditions; Cluster analysis; Comorbidities; Multimorbidity; Type 2 diabetes mellitus