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Table 3 Comparison of Swiss weights model with Base, Charlson and VW weights models based on the Net Reclassification Improvement (NRI)

From: Comparing Charlson and Elixhauser comorbidity indices with different weightings to predict in-hospital mortality: an analysis of national inpatient data

Derivation group
Comparison models NRI (95% CI) Mortality increased Pr (Up|Case) Alive increased Pr (Up|Ctrl) Mortality decreased
Pr (Down|Case)
Alive decreased
Pr (Down|Ctrl)
Swiss weights vs. Base model 0.355 (0.352–0.357) 0.448 (0.445–0.450) 0.074 (0.074–0.074) 0.134 (0.133–0.136) 0.115 (0.115–0.116)
Swiss weights vs. Charlson weights model 0.049 (0.044–0.052) 0.297 (0.294–0.299) 0.058 (0.058–0.059) 0.251 (0.250–0.253) 0.062 (0.061–0.062)
Swiss weights vs. VW weights model 0.016 (0.013–0.020) 0.157 (0.155–0.159) 0.021 (0.021–0.022) 0.143 (0.140–0.145) 0.023 (0.023–0.024)
  1. Abbreviations: NRI Net Reclassification Improvement with classification cut-off 0.023, CI confidence interval
  2. Pr (Up, Down) | (Case, Ctrl) represents the proportion of patients whose predicted probabilities increased or decreased for in-hospital mortality and alive cohorts respectively
  3. NRI = (Pr (Up|Case) - Pr (Down|Case)) + (Pr (Down|Ctrl) - Pr (Up|Ctrl))
  4. Base model: age group, sex, hospital types
  5. Charlson weights model: base and Charlson weights
  6. VW weights model: base and Elixhauser/ van Walraven weights
  7. Swiss weights model: base and Elixhauser/ Swiss weights