Table 3

Results from the two-part model on hospitalization costs

VariablesFirst-part probit of two-part model, model 1Second-part GLM with γ distribution and identity link of two-part model, model 1First-part probit of two-part model, model 2Second-part GLM with γ distribution and identity link of two-part model, model 2
Diabetes duration categories (reference: 0–2 years)
 2–5 years0.0529*** (0.0177)147.6 (369.3)0.0462*** (0.0178)106.1 (362.0)
 5–10 years0.100*** (0.0161)773.4** (339.1)0.0791*** (0.0162)568.3* (333.2)
 >10 years0.191*** (0.0175)1,215*** (373.7)0.151*** (0.0177)910.9** (371.1)
HbA1c categories (reference: HbA1c <7%)
 7% ≥ HbA1c < 8%0.0103 (0.0124)109.9 (268.4)−0.000905 (0.0124)87.46 (262.6)
 8% ≥ HbA1c < 10%0.0793*** (0.0144)927.5*** (330.3)0.0500*** (0.0146)811.1** (323.6)
 HbA1c ≥10%0.169*** (0.0243)843.6 (552.1)0.126*** (0.0246)636.8 (541.8)
Complications (reference: no complications)
 Macrovascular complications0.297*** (0.0173)1,733*** (388.8)
 Microvascular complications0.201*** (0.0162)974.5*** (357.5)
 Both types0.358*** (0.0138)2,323*** (320.1)
Constant−1.688*** (0.0369)4,521*** (693.5)−1.677*** (0.0370)4,404*** (690.8)
Observations (n)90,87413,83790,87413,837
AIC20.0620.04
BIC−117,709.7−117,854.6
Log-likelihood−38,835.91−138,739.50−38,424.52−138,652.77
  • Model 1 adjusted for age (in categories), sex, BMI (in categories), hypertension and hypercholesterolemia, and smoking habits. Model 2 adds to model 1 whether the individual has any micro- or macrovascular complications or both. Reference categories: diabetes duration of <2 years, HbA1c <7% (models 1 and 2), and no vascular complications (model 2).

  • AIC, Akaike information criterion; BIC, Bayesian information criterion.

  • The coefficient denotes probability (e.g., 0.0529 has to be interpreted as a 5.29% increase in the probability of being admitted to hospital). SEs are given in parentheses.

  • Costs in 2011 €, with SEs given in parentheses.

  • * P < 0.1;

  • ** P < 0.05;

  • *** P < 0.01.