title: The validation of cardiovascular risk scores for patients with type 2 diabetes mellitus.
abstract: OBJECTIVE
  Various cardiovascular prediction models have been developed for patients with type 2 diabetes. Their predictive performance in new patients is mostly not investigated. This study aims to quantify the predictive performance of all cardiovascular prediction models developed specifically for diabetes patients.
  
  
  METHODS
  Follow-up data of 453, 1174 and 584 type 2 diabetes patients without pre-existing cardiovascular disease (CVD) in the EPIC-NL, EPIC-Potsdam and Secondary Manifestations of ARTerial disease cohorts, respectively, were used to validate 10 prediction models to estimate risk of CVD or coronary heart disease (CHD). Discrimination was assessed by the c-statistic for time-to-event data. Calibration was assessed by calibration plots, the Hosmer-Lemeshow goodness-of-fit statistic and expected to observed ratios.
  
  
  RESULTS
  There was a large variation in performance of CVD and CHD scores between different cohorts. Discrimination was moderate for all 10 prediction models, with c-statistics ranging from 0.54 (95% CI 0.46 to 0.63) to 0.76 (95% CI 0.67 to 0.84). Calibration of the original models was poor. After simple recalibration to the disease incidence of the target populations, predicted and observed risks were close. Expected to observed ratios of the recalibrated models ranged from 1.06 (95% CI 0.81 to 1.40) to 1.55 (95% CI 0.95 to 2.54), mainly driven by an overestimation of risk in high-risk patients.
  
  
  CONCLUSIONS
  All 10 evaluated models had a comparable and moderate discriminative ability. The recalibrated, but not the original, prediction models provided accurate risk estimates. These models can assist clinicians in identifying type 2 diabetes patients who are at low or high risk of developing CVD.
authors.affiliation: Department of Vascular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van der Leeuw
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands Clinical Research Unit, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: van Dieren
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: J W J
authors.initials: JW
authors.lastname: Beulens
authors.affiliation: Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Boeing
authors.affiliation: Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: A M W
authors.initials: AM
authors.lastname: Spijkerman
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Y
authors.initials: Y
authors.lastname: van der Graaf
authors.affiliation: Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: D L
authors.initials: DL
authors.lastname: van der A
authors.affiliation: Department of Nutrition and Food Sciences, Nutritional Epidemiology, University of Bonn, Bonn, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Nöthlings
authors.affiliation: Department of Vascular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: F L J
authors.initials: FL
authors.lastname: Visseren
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: G E H M
authors.initials: GE
authors.lastname: Rutten
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: K G M
authors.initials: KG
authors.lastname: Moons
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Y T
authors.initials: YT
authors.lastname: van der Schouw
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: L M
authors.initials: LM
authors.lastname: Peelen
mesh_terms: D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D014943:Global Health; D006801:Humans; D008955:Models, Cardiovascular; D018570:Risk Assessment; D012307:Risk Factors