The prognostic value of single and repeated ≥10% FEV₁ declines for chronic lung allograft dysfunction

There is a paucity of data reporting the positive and negative predictive values (PPV, NPV) of acute declines in lung function on chronic lung allograft dysfunction (CLAD). We sought to define the predictive ability of single or repeated forced expiratory volume in the first second (FEV₁) declines for at least 3 weeks on the development of CLAD or death by 1-year. We analyzed 340 subjects with at least 3 years of follow-up data from two lung transplant centers. A single ≥10% FEV₁ decline had a PPV of 35% and NPV of 63%, and a repeated ≥10% FEV₁ decline for at least 3 weeks had a PPV of 44% and NPV of 65%. Notably, the proportion of individuals with incipient CLAD at the time of a single or repeated ≥20% FEV1 decline was 50% and 71%, respectively. These estimates could inform the development of acute lung allograft dysfunction FEV₁ thresholds as enrollment criteria or surrogate outcome measures.