Time dependent survival curves for patients with 1 or more versus no impairments on neurocognitive tests. (A) Time-dependent survival based on pretransplantation impairment shows 58 of 82 patients impaired. (B) Time-dependent survival based on impairment at 80 days shows 75 of 80 patients impaired (hazard ratio = 2.84; 95% CI, 0.8-9.7; P = 0.06.).