title: Multiple chronic conditions in type 2 diabetes mellitus: prevalence and consequences.
abstract: OBJECTIVE
  Multiple chronic comorbidities (MCCs) are an issue of growing significance in diabetes because they are highly prevalent and can increase disease burden and costs. We examined MCC patterns among patients with type 2 diabetes mellitus and identified specific comorbidity clusters associated with poor patient outcomes.
  
  
  METHODS
  We conducted a cross-sectional analysis of 161,174 patients with diabetes using electronic health record data supplied by US providers in the 2008 to 2012 Humedica data sets. We examined prevalence of MCC clusters in younger and older patients. For each of the 15 most common MCC clusters, we reported predicted probabilities for diabetes face-to-face visits, reaching glycated hemoglobin < 8%; emergency department (ED) visits; and 30-day hospital readmissions, based on logistic regression results.
  
  
  RESULTS
  The leading MCC combination was the presence of hypertension-hyperlipidemia-obesity and no other diagnosed comorbidities (19% of the sample). The most notable difference, by age, was a higher prevalence of obesity in the younger cohort. MCC clusters were more diverse among the older population: the top 10 MCC clusters accounted for 66% of older patients, compared with 78% of younger patients. Patients with certain comorbidity profiles, such as those with obesity only, were less likely to have diabetes-related face-to-face visits and to meet A1C treatment goals, and more likely to have ED visits and 30-day readmissions.
  
  
  CONCLUSIONS
  Patients with diabetes have substantial comorbidities, but the patterns vary considerably across patients and by age. Diabetes care remained suboptimal among many types of MCC patients, and patient outcomes varied by MCC profile. Specific management strategies should be developed for common MCC clusters, such as hypertension-hyperlipidemia-obesity.
authors.affiliation: Center for the Evaluation of Value and Risk in Health, Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, 800 Washington St, Box 63, Boston, MA 02111. E-mail: plin@tuftsmedicalcenter.org.
authors.forename: Pei-Jung
authors.initials: PJ
authors.lastname: Lin
authors.forename: David M
authors.initials: DM
authors.lastname: Kent
authors.forename: Aaron
authors.initials: A
authors.lastname: Winn
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Cohen
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Neumann
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D016000:Cluster Analysis; D015897:Comorbidity; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D006949:Hyperlipidemias / Q000175:diagnosis / Q000453:epidemiology*; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D010359:Patient Readmission / Q000706:statistics & numerical data; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis