Table 1 Determinants of annual healthcare costs, mean annual predictions and cost ratios (patients with vs. without diabetes), Root Mean Squared Errors (RMSE), by several data modeling approaches
Model | Diabetes (CI 95 %) | Cost (€) per person/year, patients with diabetes (N = 33,792) | CI 95 %a | Cost (€) per person/year, patients without diabetes (N = 863,122) | CI 95 %a | Cost Ratio (with vs. without diabetes) | RMSE | ||
|---|---|---|---|---|---|---|---|---|---|
One-part models | |||||||||
Normal (€) | 1,832.76 | 1,795.56–1,869.95 | 3348.6 | 3343.8–3353.9 | 831.2 | 829.8–832.4 | 4.03 | 3,342.4 | |
Lognormal b (exp β) | 6.0 | 5.84–6.16 | 6146.5 | 6116.9–6178.6 | 1343.6 | 1340.5–1347.0 | 4.57 | 3,670.0 | |
Gamma (exp β) | 2.6 | 2.56–2.67 | 3878.1 | 3867.0–3891.1 | 826.1 | 824.8–827.3 | 4.69 | 3,351.1 | |
Two-part models | |||||||||
Part 1 | |||||||||
Logistic (OR) | 2.40 | 2.18–2.64 | - | ||||||
Part 2 | |||||||||
Normal (€) | 1,710.36 | 1,668.40–1,752.32 | 3392.0 | 3387.2–3397.5 | 1058.8 | 1057.4–1060.4 | 3.20 | 3,732.2 | |
Lognormal (exp β) | 3.3 | 3.21–3.32 | 4119.9 | 4104.4–4136.3 | 1175.2 | 1173.2–1177.6 | 5.60 | 3,760.6 | |
Gamma (exp β) | 2.2 | 2.21–2.28 | 3700.1 | 3690.0–3711.1 | 1050.8 | 1049.5–1052.4 | 3.50 | 3,735.6 | |
Two part model (logistic + gamma) | 3662.26 | 3652.07–3673.25 | 891.9 | 890.63–893.54 | 4.10 | 3,739.8 | |||