title: Educational disparities in mortality among patients with type 2 diabetes in The Netherlands (ZODIAC-23).
abstract: BACKGROUND
  Relative mortality differences between educational level in mortality have been reported among diabetic as well as among non-diabetic subjects in Europe, but data on absolute differences are lacking. We studied the effect of educational disparities on mortality in a Dutch prospective cohort of type 2 diabetes mellitus (T2DM) patients.
  
  
  METHODS
  This study was part of the ZODIAC study, a prospective observational study of patients with T2DM. Data on educational level were first collected on 19 May 1998, and from this date on, 858 patients were included in 1998; educational level was known for 656 patients. Vital status was assessed in 2009. The relationship between mortality and educational level was studied using a Cox proportional hazard model, the relative index of inequality (RII), slope index of inequality (SII) and the population attributable risk (PAR). Educational level was divided into four categories; the highest educational level was used as reference.
  
  
  RESULTS
  After a median follow-up time of 9.7 years, 365 out of 858 patients had died. The hazard ratio of primary education for total mortality was 3.02 (95% CI 1.44-6.34). The RII was 2.85 (95% CI 1.21-6.67), the absolute difference in the risk for mortality (SII) was 384 deaths (95% CI 49-719) per 10,000 follow-up years. PAR for patients with the lowest level of education was 51.4%.
  
  
  CONCLUSIONS
  A low educational level had a higher impact on mortality than having a macrovascular complication. Given the substantial differences in mortality between educational levels in T2DM, more understanding of underlying (modifiable) mechanisms is necessary.
authors: Diabetes Centre, Isala Clinics, Zwolle, The Netherlands.
authors: G W D
authors: GW
authors: Landman
authors: N
authors: N
authors: Kleefstra
authors: K J J
authors: KJ
authors: van Hateren
authors: R O B
authors: RO
authors: Gans
authors: H J G
authors: HJ
authors: Bilo
authors: K H
authors: KH
authors: Groenier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality*; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies