title: Risk score for prediction of 10 year dementia risk in individuals with type 2 diabetes: a cohort study.
abstract: BACKGROUND
  Although patients with type 2 diabetes are twice as likely to develop dementia as those without this disease, prediction of who has the highest future risk is difficult. We therefore created and validated a practical summary risk score that can be used to provide an estimate of the 10 year dementia risk for individuals with type 2 diabetes.
  
  
  METHODS
  Using data from two longitudinal cohorts of patients with type 2 diabetes (aged ≥60 years) with 10 years of follow-up, we created (n=29,961) and validated (n=2413) the risk score. We built our prediction model by evaluating 45 candidate predictors using Cox proportional hazard models and developed a point system for the risk score based on the size of the predictor's β coefficient. Model prediction was tested by discrimination and calibration methods. Dementia risk per sum score was calculated with Kaplan-Meier estimates.
  
  
  RESULTS
  Microvascular disease, diabetic foot, cerebrovascular disease, cardiovascular disease, acute metabolic events, depression, age, and education were most strongly predictive of dementia and constituted the risk score (C statistic 0·736 for creation cohort and 0·746 for validation cohort). The dementia risk was 5·3% (95% CI 4·2-6·3) for the lowest score (-1) and 73·3% (64·8-81·8) for the highest (12-19) sum scores.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first risk score for the prediction of 10 year dementia risk in patients with type 2 diabetes mellitus. The risk score can be used to increase vigilance for cognitive deterioration and for selection of high-risk patients for participation in clinical trials.
  
  
  BACKGROUND
  Kaiser Permanente Community Benefit, National Institute of Health, Utrecht University, ZonMw, and Fulbright.
authors.affiliation: Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, Netherlands; Kaiser Permanente Division of Research, Oakland, CA, USA.
authors.forename: Lieza G
authors.initials: LG
authors.lastname: Exalto
authors.affiliation: Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, Netherlands.
authors.forename: Geert Jan
authors.initials: GJ
authors.lastname: Biessels
authors.affiliation: Kaiser Permanente Division of Research, Oakland, CA, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Karter
authors.affiliation: Department of Internal Medicine, University of Chicago, Chicago, IL, USA.
authors.forename: Elbert S
authors.initials: ES
authors.lastname: Huang
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA.
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Katon
authors.affiliation: Kaiser Permanente, Department of Endocrinology, Santa Rosa, CA, USA.
authors.forename: Jerome R
authors.initials: JR
authors.lastname: Minkoff
authors.affiliation: Kaiser Permanente Division of Research, Oakland, CA, USA. Electronic address: rachel.whitmer@kp.org.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Whitmer
mesh_terms: D000367:Age Factors; D002318:Cardiovascular Diseases / Q000150:complications; D002561:Cerebrovascular Disorders / Q000150:complications; D015331:Cohort Studies; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology*; D003863:Depression / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000453:epidemiology*; D017719:Diabetic Foot / Q000150:complications; D004522:Educational Status; D006801:Humans; D053208:Kaplan-Meier Estimate; D016016:Proportional Hazards Models; D018570:Risk Assessment / Q000706:statistics & numerical data*; D012307:Risk Factors