Table 4.
Post-Transplantation Survival of HPS Transplant Recipients Based on Pre-transplantation Room-Air Oxygenation
| Variable | Standard PaO2 categoriesa
|
Cubic spline PaO2 categoriesb
|
||
|---|---|---|---|---|
| Multivariable HR (95% CI) | P value | Multivariable HR (95% CI) | P value | |
| Standard PaO2 categories | .04 | |||
| <50 mm Hg (n = 175) | 1.56 (1.02–2.38) | |||
| 50–59 mm Hg (n = 347) | 1 | |||
| 60–69 mm Hg (n = 88) | 1.51 (0.88–2.58) | |||
| Cubic spline PaO2 categories | .01 | |||
| ≤44.0 mm Hg (n = 65) | 1.58 (1.15–2.18) | |||
| 44.1–54.0 mm Hg (n = 242) | 1 | |||
| 54.1–61.0 mm Hg (n = 250) | 0.74 (0.55–1.01) | |||
| ≥61.1 mm Hg (n = 50) | 1.56 (0.77–3.17) | |||
| Age at transplantationc | 1.11 (0.88–1.39) | .38 | 1.09 (0.82–1.45) | .56 |
| Primary diagnosis | .02 | .02 | ||
| Hepatitis C | 1 | 1 | ||
| Alcohol | 0.86 (0.50–1.46) | 0.85 (0.47–1.52) | ||
| Hepatitis B | 0.54 (0.07–4.27) | 0.50 (0.30–0.85) | ||
| Nonalcoholic steatohepatitis/cryptogenic | 0.63 (0.36–1.10) | 0.62 (0.39–0.99) | ||
| Cholestatic | 0.18 (0.02–1.34) | 0.18 (0.07–0.49) | ||
| Autoimmune | 0.73 (0.29–1.85) | 0.73 (0.22–2.46) | ||
| Other | 2.23 (1.18–4.24) | 2.22 (1.35–3.66) | ||
| Donor risk index | 2.33 (1.51–3.59) | <.001 | 2.39 (1.87–3.04) | <.001 |
| Serum albumin at transplantation | 0.79 (0.56–1.10) | .20 | 0.78 (0.53–1.13) | .20 |
| Blood type | .04 | .03 | ||
| O | 1 | 1 | ||
| A | 1.06 (0.70–1.60) | 1.09 (0.76–1.54) | ||
| B | 0.71 (0.33–1.52) | 0.67 (0.40–1.13) | ||
| AB | 1.01 (0.36–2.86) | 1.08 (0.50–2.32) | ||
| Race/ethnicity | .06 | .009 | ||
| White | 1 | 1 | ||
| Black | 1.49 (0.58–3.83) | 1.35 (0.81–2.25) | ||
| Hispanic | 0.78 (0.42–1.45) | 0.79 (0.50–1.26) | ||
| Asian | 0.77 (0.10–5.80) | 0.81 (0.25–2.65) | ||
| Other | 1.25 (0.17–9.23) | 1.16 (0.30–4.50) | ||
AIC of model 1292.12. Final model did not include final laboratory MELD score, male sex, time period of transplantation, UNOS region, or final blood type, which were not significant in univariable models (P > .3), and were not confounders (did not change HR for PaO2 category by 10%). When compared with the reference PaO2 category of 50 to 59 mm Hg, the only group with a significantly increased risk of post-transplantation mortality in pairwise comparisons was the ≤50 mm Hg group (P = .04).
AIC of model 1288.18. Final model did not include final laboratory MELD score, time period of transplantation, UNOS region as they were not significant in univariable models (P > .3), and were not confounders (did not change HR for PaO2 category by 10%). Hazard ratio for male sex in final model: 0.86, 95% CI: 0.69–1.08; P = .19. The 15 transplant recipients with a PaO2 >70 mm Hg were excluded. When compared with the reference PaO2 category of 44.1–54.0 mm Hg, the only group with a significantly increased risk of post-transplantation mortality in pairwise comparisons was the ≤44.0 mm Hg group (P = .005).
Hazard for every increase in 10 years at transplantation.