Table 2.
Negative Binomial Regression Analysis Examining Independent Factors Associated With Increasing Hospital LTAC Utilization After Critical Illnessa
| Variable | IRR | P |
|---|---|---|
| Bed size | ||
| <100 | Referent | |
| 100–200 | 1.23 (1.11–1.36) | <.001 |
| >200 | 1.18 (1.06–1.31) | .003 |
| Ownership | ||
| Nonprofit | Referent | |
| For-profit | 1.25 (1.16–1.34) | <.001 |
| Government | 1.06 (0.97–1.15) | .21 |
| Teaching status | ||
| Nonteaching | Referent | |
| Small teaching | 1.01 (0.94–1.08) | .88 |
| Large teaching | 1.11 (1.01–1.22) | .03 |
| MSA size | ||
| <100,000 | Referent | |
| 100,000 to 1 million | 1.08 (0.97–1.21) | .17 |
| >1 million | 1.13 (1.00–1.28) | .05 |
| Distance to nearest LTAC (miles) | ||
| >50 | Referent | |
| >25–50 | 1.40 (1.18–1.65) | <.001 |
| >15–25 | 1.70 (1.42–2.04) | <.001 |
| >5–15 | 2.44 (2.06–2.89) | <.001 |
| >0–5 | 3.25 (2.74–3.85) | <.001 |
| 0 (HWH) | 4.13 (3.47–4.91) | <.001 |
| State with certificate of need law | 0.69 (0.59–0.79) | <.001 |
| Census region | ||
| Northeast | Referent | |
| Southeast | 1.75 (1.46–2.10) | <.001 |
| Midwest | 1.35 (1.12–1.63) | .002 |
| West | 1.40 (1.14–1.70) | .001 |
| Per capita LTAC beds in HRR | ||
| 1–200 | Referent | |
| 201–400 | 1.31 (1.13–1.53) | <.001 |
| >400 | 1.34 (1.10–1.63) | <.003 |
Note: LTAC = long-term acute care hospital; IRR = incidence rate ratio; MSA = metropolitan statistical area; HWH = hospital within a hospital; HRR = Dartmouth Atlas hospital referral region
a
Utilization rates are adjusted for differences in case mix across hospitals.