Abstract Background Chronic Obstructive Pulmonary Disease (COPD) is a chronic lung disease characterized by airflow obstruction. Currently, we use the post-bronchodilator Forced Expiratory Volume (FEV)1 %predicted in assessing severity of airflow obstruction. However, in 2022, ATS/ERS, proposed the use of z scores to evaluate the severity of airflow obstruction which reduces the bias relating to height, sex, age and ethnicity. Currently it is not known whether which of the two classification correlates better with Filipino COPD Assessment Test (CAT). If this study will show that the severity of airflow limitation using the z-score will show better correlation, then a particular patient if there is divergence between the airflow limitation. Objective To determine if there is a difference in the correlation of the post-bronchodilator Z-score and post-bronchodilator FEV1% predicted with the CAT score among Filipino COPD patients. Methodology This is a single-center, prospective cross-sectional study including adults who spirometry testing at a tertiary hospital from June 2024-April 2025. Result There were 56 Filipino COPD patients that were enrolled in the study. The study showed a negative correlation between CAT and post-bronchodilator FEV1% predicted (r= -.261, p = 0.052), post-bronchodilator FEV1 z-score (r= -.209, p = 0.842). There is a similar trend of increasing mean CAT scores as the severity of COPD increases in both GOLD classification and post-bronchodilator FEV1 z-score. Conclusion The study findings show a negative correlation between both FEV1% predicted and post-bronchodilator FEV1 z-score to CAT score, although neither reached statistical significance, there is consistent trend indicating worsening airflow limitation with increasing symptom burden. Our results also showed that post-bronchodilator FEV1% predicted showed better correlation to CAT score compared to post-bronchodilator FEV1 z score supporting its current use for classification of severity of obstruction. This abstract is funded by: None
Barretto et al. (Fri,) studied this question.