Table 4.
Impact of CKD at 1 year on survival and transplant outcomes using time-varying approach
| Mortality | RFS | GRFS | TRM | Relapse | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | HR (95% CI) | P-value | HR (95% CI) | P-value | HR (95% CI) | P-value | HR (95% CI) | P-value | HR (95% CI) | P-value |
| CKD at 1 year | 1.93 (1.02–3.66) | 0.04 | 1.73 (0.84–3.53) | 0.13 | 1.43 (0.53–3.89) | 0.48 | 1.47 (0.61–3.56) | 0.39 | 1.28 (0.42–3.89) | 0.66 |
| Age at transplant | 1.01 (0.99–1.02) | 0.35 | 1.01 (1.00–1.02) | 0.06 | 1.01 (0.99–1.02) | 0.16 | 1.04 (1.02–1.06) | 0.0007 | 0.99 (0.97–1.00) | 0.12 |
| Diabetes | 2.26 (1.52–3.38) | <0.0001 | 1.95 (1.25–3.04) | 0.003 | ||||||
| Conditioning regimen (MAC versus RIC) |
0.89 (0.57–1.40) | 0.61 | 0.91 (0.58–1.41) | 0.66 | 1.10 (0.80–1.51) | 0.58 | 1.04 (0.58–1.85) | 0.90 | 0.74 (0.40–1.40) | 0.35 |
| GVHD prophylaxis (ATG-PTCy-CSA versus others) |
0.49 (0.34–0.71) | 0.0001 | 0.69 (0.47–1.01) | 0.05 | 0.52 (0.40–0.68) | <0.0001 | 0.73 (0.48–1.11) | 0.14 | 0.89 (0.53–1.49) | 0.65 |
| aGVHD (grade 3–4) |
1.88 (1.25–2.83) | 0.0002 | 1.98 (1.29–3.06) | 0.002 | ||||||
| cGVHD (moderate/severe) |
0.35 (0.22–0.54) | <0.0001 | 0.36 (0.24–0.55) | <0.0001 | 0.15 (0.06–0.38) | <0.0001 | ||||
In this model, associations between CKD and OS, RFS, GRFS, TRM and relapse were examined using extended Cox proportional hazard models and extended Fine and Gray's competing risk models, where CKD was treated as a time-varying covariate that could potentially change status at 1 year time point. This permitted us to examine the associations between CKD and survival and transplant outcomes for the full cohort. The date of allogeneic HSCT served as the time-origin for survival analysis.
To build each of the multivariable models, variables with P < 0.10 from the univariable analyses (not shown) were chosen, on which backward selection method was applied to retain variables with statistical relevance (P < 0.05). Variables with clinical importance (i.e. variables associated with worse outcomes in previous published studies) were also included, regardless of their statistical significance.
CKD = chronic kidney disease; RFS = relapse-free survival; GRFS = graft-versus-host disease-free/relapse-free survival; TRM = transplant-related mortality; HR = hazard ratio; MAC = myeloablative conditioning; RIC = reduced intensity conditioning regimen; GVHD = graft-versus-host-disease; aGVHD = acute graft-versus-host disease; cGVHD = chronic graft-versus-host disease; ATG-PTCy-CSA = anti-thymocyte globulin with post-transplant cyclophosphamide and cyclosporine.