Table 3. Association Between Donor-Recipient Biological Relationship and Outcomes After Living Donor Kidney Transplanta.
| Unadjusted | Model 1 | Model 2 | Model 3 | |||||
|---|---|---|---|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | HR (95% CI) | P value | HR (95% CI) | P value | |
| Death-censored graft failure | ||||||||
| Donor related to recipient, full cohort | 1.01 (0.97-1.04) | .77 | 1.26 (1.21-1.31) | <.001 | 1.06 (1.02-1.11) | .005 | 1.05 (1.01-1.10) | .03 |
| Donor related to recipient, cystic kidney diseaseb | 0.91 (0.78-1.07) | .26 | 1.08 (0.90-1.30) | .40 | 1.04 (0.86-1.25) | .68 | 1.03 (0.85-1.24) | .77 |
| Donor related to recipient, noncystic kidney diseasec | 0.95 (0.91-0.98) | .004 | 1.2 (1.15-1.25) | <.001 | 1.07 (1.02-1.11) | .005 | 1.05 (1.01-1.10) | .03 |
| Donor related to recipient, donor African Americand | 1.03 (0.95-1.12) | .49 | 1.19 (1.07-1.31) | .001 | 1.13 (1.02-1.25) | .02 | 1.12 (1.01-1.23) | .03 |
| Donor related to recipient, donor not African Americane | 0.93 (0.90-0.97) | <.001 | 1.15 (1.10-1.21) | <.001 | 1.04 (1.00-1.10) | .08 | 1.03 (0.98-1.08) | .20 |
| Composite graft failure | ||||||||
| Donor related to recipient, full cohort | 1.02 (0.99-1.04) | .25 | 1.16 (1.13-1.20) | <.001 | 1.13 (1.09-1.17) | <.001 | 1.12 (1.08-1.15) | <.001 |
| Donor related to recipient, cystic kidney diseaseb | 0.96 (0.86-1.07) | .46 | 1.06 (0.93-1.20) | .42 | 1.06 (0.93-1.22) | .37 | 1.06 (0.92-1.21) | .43 |
| Donor related to recipient, non–cystic kidney diseasec | 0.96 (0.93-0.99) | .002 | 1.11 (1.07-1.14) | <.001 | 1.13 (1.10-1.17) | <.001 | 1.12 (1.08-1.16) | <.001 |
| Donor related to recipient, donor African Americand | 1.05 (0.98-1.13) | .17 | 1.17 (1.07-1.27) | <.001 | 1.13 (1.03-1.22) | .006 | 1.11 (1.02-1.21) | .02 |
| Donor related to recipient, donor not African Americane | 0.98 (0.95-1.00) | .09 | 1.11 (1.07-1.15) | <.001 | 1.11 (1.07-1.15) | <.001 | 1.10 (1.06-1.14) | <.001 |
| Recipient death | ||||||||
| Donor related to recipient, full cohort | 1.00 (0.96-1.03) | .88 | 1.05 (1.01-1.10) | .02 | 1.07 (1.02-1.12) | .003 | 1.06 (1.01-1.11) | .02 |
| Donor related to recipient, cystic kidney diseaseb | 0.95 (0.82-1.11) | .54 | 0.99 (0.83-1.18) | .94 | 0.96 (0.80-1.15) | .64 | 0.95 (0.79-1.15) | .62 |
| Donor related to recipient, non–cystic kidney diseasec | 0.95 (0.91-0.98) | .003 | 1.00 (0.96-1.05) | .99 | 1.08 (1.03-1.13) | .002 | 1.06 (1.01-1.12) | .01 |
| Donor related to recipient, donor African Americand | 1.11 (0.99-1.24) | .09 | 1.13 (0.99-1.29) | .07 | 0.99 (0.86-1.14) | .91 | 0.98 (0.85-1.12) | .74 |
| Donor related to recipient, donor not African Americane | 0.99 (0.95-1.03) | .55 | 1.05 (1.00-1.10) | .05 | 1.05 (1.00-1.10) | .06 | 1.04 (0.99-1.09) | .16 |
Abbreviation: HR, hazard ratio.
The HRs are for biologically related donor-recipient pair (reference group, unrelated donor-recipient pair). Model 1 variables: donor-recipient relationship, number of HLA-A mismatches, number of HLA-B mismatches, and number of HLA-DR mismatches. Model 2: model 1 plus donor age, donor sex, donor race (categorical variable; reference: White; groups: Black/African American, Hispanic, other; not included in models stratified by donor race), donor predonation creatinine level, recipient age (years), recipient sex, recipient diabetes, recipient peripheral vascular disease, recipient functional status (impaired vs unimpaired), recipient dialysis time (categorical variable; reference: preemptive transplant; groups: <1 year and ≥1 year, unknown), recipient insurance type (categorical variable; reference: private insurance; groups: Medicare, Medicaid, other), recipient employment status (reference: employed; categories: not employed, unknown employment status), recipient cause of kidney disease (cystic vs noncystic; not included in models stratified by cystic disease), and ABO-incompatible transplant. Model 3: model 2 plus era (2000-2004, 2005-2009, or 2010-2014, treated as a categorical variable).
Group sizes: related, n = 2530; not related, n = 4600.
Group sizes: related, n = 40 644; not related, n = 25 206.
Group sizes: related, n = 6958; not related, n = 2541.
Group sizes: related, n = 36 216; not related, n = 27 265.