Table 4.
Association of intensive care unit admission on hospital costs for chronic obstructive pulmonary disease, heart failure, and acute myocardial infarction
| Model | Absolute Difference (95% CI) | P value |
|---|---|---|
| COPD (n = 604,894) | ||
| Unadjusted regression | $11,136 ($10,790 to $11,482) | <0.001 |
| Instrumental variable*† | $277 (–$1,750 to $2,304) | 0.79 |
| HF (n = 626,174) | ||
| Unadjusted regression | $9,383 ($8,826 to $9,940) | <0.001 |
| Instrumental variable | $2,608 ($1,377 to $3,840) | <0.001 |
| AMI (n = 324,729) | ||
| Unadjusted regression | $12,037 ($11,636 to $12,438) | <0.001 |
| Instrumental variable | $4,922 ($2,665 to $7,180) | <0.001 |
Definition of abbreviations: AMI = acute myocardial infarction; CI = confidence interval; COPD = chronic obstructive pulmonary disease; HF = heart failure.
Model adjusted for all variables in Tables 1 and 2 in addition to all 29 individual Elixhauser comorbidities. 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.