Table 3.
Independent Predictors of Nonindex Hospital Versus Index Hospital 30-d Readmission After CABG and SAVR: Nationally Weighted Resultsa
| Categorical age, y | ||
| 18–44 | 1.00 (reference) | 1.00 (reference) |
| 45–54 | 1.13 (0.92–1.39) | 1.09 (0.84–1.43) |
| 55–64 | 1.18 (0.97–1.43) | 1.34 (1.03–1.74) |
| 65–74 | 1.31 (1.08–1.59) | 1.45 (1.14–1.84) |
| 75–84 | 1.43 (1.17–1.75) | 1.85 (1.44–2.38) |
| >84 | 1.48 (1.17–1.88) | 2.16 (1.65–2.85) |
| Female | 1.00 (0.94–1.06) | 1.11 (1.00–1.24) |
| Median income quartile | ||
| Ql (lowest) | 1.00 (reference) | 1.00 (reference) |
| Q2 | 1.11 (1.01–1.21) | 1.17 (1.00–1.37) |
| Q3 | 1.17 (1.07–1.29) | 1.15 (0.98–1.35) |
| Q4 (highest) | 1.21 (1.08–1.36) | 1.26 (1.06–1.48) |
| Patient residential population | ||
| Urban, metro area ≥ 1 million | 1.00 (reference) | 1.00 (reference) |
| Suburban, metro area ≥ 1million | 1.22 (1.15–1.28) | 1.15 (0.96–1.36) |
| 250,000–999,999 | 0.80 (0.75–0.85) | 0.91 (0.76–1.08) |
| <250,000 | 1.28 (1.20–1.36) | 1.12 (0.88–1.43) |
| Operative urgency | ||
| Emergent/urgent | 1.00 (reference) | 1.00 (reference) |
| Elective | 0.93 (0.87–1.01) | 1.13 (1.02–1.27) |
| Charlson Comorbidity Index | ||
| 0 (lowest) | 1.00 (reference) | 1.00 (reference) |
| 1 | 1.05 (0.96–1.16) | 1.07 (0.93–1.24) |
| 2 | 1.15 (1.04–1.26) | 1.13 (0.96–1.33) |
| 3 | 1.18 (1.06–1.31) | 1.11 (0.94–1.32) |
| 4 | 1.31 (1.17–1.47) | 1.28 (1.04–1.59) |
| ≥5 (highest) | 1.50 (1.33–1.69) | 1.51 (1.17–1.93) |
| Hospital bed size | ||
| Small | 1.00 (reference) | 1.00 (reference) |
| Medium | 0.66 (0.53–0.87) | 0.71 (0.55–0.90) |
| Large | 0.70 (0.57–0.86) | 0.78 (0.64–0.95) |
| Hospital teaching status | ||
| Metropolitan nonteaching | 1.00 (reference) | 1.00 (reference) |
| Metropolitan teaching | 1.19 (1.07–1.32) | 1.43 (1.24–1.65) |
| Nonmetropolitan hospital | 0.26 (0.20–0.34) | 0.46 (0.27–0.78) |
| Patient residential population | ||
| Urban, metro area ≥1 million | 1.00 (reference) | 1.00 (reference) |
| Suburban, metro area ≥1 | 1.20 (1.06–1.36) | 1.15 (0.96–1.36) |
| million | ||
| 250,000–999,999 | 0.74 (0.64–0.84) | 0.90 (0.75–1.08) |
| <250,000 | 0.83 (0.70–0.99) | 1.12 (0.88–1.43) |
| Specific comorbidities | ||
| Hypertension | 1.21 (0.83–1.77) | 1.03 (0.56–1.90) |
| Heart failure | 0.84 (0.51–1.38) | 1.01 (0.67–1.52) |
| Prior transient ischemic attack/stroke | 1.23 (1.13–1.35) | 1.21 (1.01–1.45) |
Risk-adjusted model was calculated using inverse probability of treatment weighting based on calculated propensity scores for a priori defined age, gender, income, operative emergency, CCI, hospital size, hospital teaching status, and patient residential population. The resultant model was confirmed not to be significantly different from the complete models (inclusive of all terms shown in Supplemental Table 1) based on comparison of the ln(likelihoods) for the full and reduced nested models.
CABG, coronary artery bypass grafting; CI, confidence interval; OR, odds ratio; Q, quartile; SAVR, surgical aortic valve replacement.