Table 1.
Characteristics of Medicare patients undergoing bypass surgery (n=157070)
| Characteristic | Percent or Mean (SD) |
|---|---|
| Dependent variable | |
| 30-day readmission | 17.2 |
| Independent variables | |
| Postoperative length of stay in days | 7.4 (4.4) |
| Age in years | 73.8 (5.9) |
| Female | 31.3 |
| Race/Ethnicity | |
| White | 90.3 |
| Black | 5.3 |
| Other | 4.4 |
| Admission type | |
| Elective | 49.0 |
| Emergent | 25.0 |
| Urgent | 25.7 |
| Other | 0.3 |
| Acute myocardial infarction at admission | 26.3 |
| Cardiac shock at admission | 2.5 |
| Number of comorbidities | |
| 0 | 3.3 |
| 1 | 15.5 |
| 2 | 28.9 |
| 3 | 28.5 |
| ≥4 | 23.9 |
| Major teaching hospital | 26.5 |
| Ownership status of the hospital | |
| For-profit | 15.0 |
| Non-for-profit | 76.7 |
| Government-owned | 8.3 |
| Rural hospital | 5.6 |
| Instrumental variable | |
| Risk-adjusted length of stay for GI hemorrhage (natural-log transformed) |
0.98 (0.09) |