Bronchiolitis obliterans syndrome (BOS) remains the main cause of graft loss after lung transplantation. Stage 0-p was recently added to the staging criteria to detect early deterioration in allograft function that might presage BOS stage 1. We assessed the predictive value of stage 0-p by retrospectively analyzing spirometric data for 203 adult bilateral lung transplant recipients. The FEV(1) criterion for stage 0-p had a positive predictive value of 79% and a negative predictive value of 82%. In contrast, the FEF(25-75%) criterion for stage 0-p had a positive predictive value of 52% and a negative predictive value of 72%. Fifty-seven percent of subjects who developed stage 0-p by the FEV(1) criterion progressed to stage 1 within 1 year, whereas only 37% of those who developed stage 0-p by the FEF(25-75%) criterion progressed to stage 1 within 1 year. We conclude that the FEV(1) criterion for stage 0-p is a reasonable predictor of BOS stage 1 after bilateral lung transplantation, but the FEF(25-75%) criterion for stage 0-p is not predictive of BOS stage 1 after bilateral lung transplantation.