Table 4.

Integrated Discrimination Improvement (IDI)of Comorbidity Scores in Predicting Surgical Outcomes

Comorbidity Score IDI (%)	30-Day Mortality	1-Year Mortality	30-Day Readmission	Complications	Failure To Rescue
Baseline model (age, gender, race/ethnicity, procedure type, dual eligibility status, original reason for entitlement)	Ref	Ref	Ref	Ref	Ref
Comorbidity scores with disease categories †
Charlson disease categories	1.96	4.96	1.18	3.36	1.74
Elixhauser disease categories	2.37	5.82	1.43	3.99	2.17
Combined disease categories	2.31	5.66	1.36	3.85	2.07
CDS disease categories	1.24	3.17	0.96	1.91	1.05
Diagnosis-based summary comorbidity score ‡
CCS original	1.03	3.79	0.73	1.96	0.85
CCS/Schneeweiss	1.42	4.33	0.97	2.63	1.23
CCS/Quan	1.07	3.82	0.67	1.75	0.87
Royal College of Surgeons CCS	1.29	3.47	0.77	2.33	1.07
CCS/number of disease	1.30	3.47	0.79	2.36	1.08
Elixhauser summary score	1.71	4.74	0.90	2.27	1.51
Elixhauser/number of disease	0.71	1.96	0.78	1.84	0.63
Combined Comorbidity Score	1.88	5.45	1.00	2.82	1.60
Combined Comorbidity/number of disease	1.01	2.75	0.82	2.20	0.91
CMS-HCC	4.59	9.60	1.27	9.37	5.24
Prescription-based summary comorbidity score
CDS	0.10	0.46	0.35	0.63	0.11
CDS/number of disease	0.06	0.11	0.10	0.23	0.07

Abbreviations: CCS, Charlson comorbidity score; CMS-HCC, Center for Medicare & Medicaid – Hierarchical Conditions Categories; CDS, chronic disease score

^†Top 2 comorbidity scores from disease categories are highlighted in light gray color.

^‡Top 2 comorbidity scores from diagnosis-based summary score are highlighted in light gray color.