Table 3.

Multivariable Linear Mixed Model for prediction of long-term Functional Status as measured by Karnofsky Performance Score

KPS = 75.711 − 2.081 (a) + 0.128 (b) + 0.825 (c) + 2.6 (p) − 3.217 (t) + 1.178(c)(t) − 0.682 (g) + 0.039 (r) + 0.027 (I) + 0.086 (d_a) + 0.810 (d_b) + 2.378 (d_c) −0.824 (d_o).

a = age (0 for 18–64, 1 for ≥65), b = KPS at transplantation, c = center volume (0 for 1–19 LT per year, 1 for ≥20 LT per year), p = LT procedure type (0 for SLT, 1 for BLT), t = years after transplantation, g = gender (0 for male, 1 for female), r = race (0 for non-white, 1 for white), I = LAS at transplantation, d = LAS diagnosis group (0 for d_d, 1 for d_a, b or c).

We tested several interactions including age group, time after transplantation, KPS at transplantation, center volume and LT procedure type but kept only the interaction found to be significant (p <0.05) in the final model, center volume by time interaction. The model allowed random effects for the intercepts and slopes by patient and facility level to account for possible correlation among patients in the same transplantation center.

Abbreviations: Karnofsky Performance Score (KPS), Lung transplantation (LT), Single LT (SLT), bilateral LT (BLT), Lung allocation score (LAS).