Table 3.
Association of intensive care unit admission on 30-day mortality for chronic obstructive pulmonary disease, heart failure, and acute myocardial infarction
| Model | ICU Patients | Ward Patients | Absolute Difference (95% CI) | P Value |
|---|---|---|---|---|
| COPD (n = 604,894) | ||||
| Unadjusted regression | 22.2% | 5.1% | 17.1% (16.6 to 17.5) | <0.001 |
| Instrumental variable*† | 8.3% | 8.6% | −0.3% (–3.5 to 2.8) | 0.84 |
| HF (n = 626,174) | ||||
| Unadjusted regression | 18.2% | 9.1% | 9.1% (8.6 to 9.7) | <0.001 |
| Instrumental variable | 12.1% | 11.0% | 1.1% (–0.4 to 2.6) | 0.14 |
| AMI (n = 324,729) | ||||
| Unadjusted regression | 17.3% | 13.8% | 3.5% (3.0 to 4.0) | <0.001 |
| Instrumental variable | 15.9% | 16.3% | −0.4% (–2.2 to 1.4) | 0.65 |
Definition of abbreviations: AMI = acute myocardial infarction; CI = confidence interval; COPD = chronic obstructive pulmonary disease; HF = heart failure; ICU = intensive care unit.
Model adjusted for all variables in Tables 1 and 2 in addition to all 29 individual Elixhauser comorbidities. The Angus organ failure score, which identifies severity of illness by patient organ failures derived from the administrative record with a maximum score of six, was defined to include all organ failures numbered 0 to 5 or more. Higher scores indicate more organ failures. Hospital region included the nine U.S. census defined regions. All standard errors for models were adjusted for clustering of patients within hospitals.