Percent BSA and survival. Survival among patients with ScGVHD with percent BSA involvement above and below the median (37.4%) for the entire ScGVHD group. Log-rank (P = .015). In multivariable analysis, after adjusting for NIH lung score, Karnofsky score, and lymphocyte count (factors associated with survival in this cohort on previous analyses), percent-BSA ScGVHD was no longer associated with survival.