COPD exacerbations and patient-reported outcomes according to post-bronchodilator FEV1 - a post-hoc analysis of pooled data.

BACKGROUND: Management strategies of chronic obstructive pulmonary disease (COPD) need to be tailored to the forced expiratory volume in one second (FEV1), exacerbations, and patient-reported outcomes (PROs) of individual patients. In this study, we analyzed the association and correlation between the FEV1, exacerbations, and PROs of patients with stable COPD. METHODS: This was a post-hoc analysis of pooled data from two cross-sectional studies that were previously conducted in Malaysia from 2017 to 2019, the results of which had been published separately. The parameters measured included post-bronchodilator FEV1 (PB-FEV1), exacerbations, and scores of modified Medical Research Council (mMRC), COPD Assessment Test (CAT), and St George's Respiratory Questionnaire for COPD (SGRQ-c). Descriptive, association, and correlation statistics were used. RESULTS: Three hundred seventy-four patients were included in the analysis. The PB-FEV1 predicted was < 30% in 85 (22.7%), 30-49% in 142 (38.0%), 50-79% in 111 (29.7%), and ≥ 80% in 36 (9.6%) patients. Patients with PB-FEV1 < 30% predicted had significantly more COPD exacerbations than those with PB-FEV1 30-49% predicted (p < 0.001), 50-79% predicted (p < 0.001), and ≥ 80% predicted (p = 0.002). The scores of mMRC, CAT, and SGRQ-c were not significantly higher in patients with more severe airflow limitation based on PB-FEV1 (p = 0.121-0.271). The PB-FEV1 predicted had significant weak negative correlations with exacerbations (r = - 0.182, p < 0.001), mMRC (r = - 0.121, p = 0.020), and SGRQ-c scores (r = - 0.114, p = 0.028). There was a moderate positive correlation between COPD exacerbations and scores of mMRC, CAT, and SGRQ-c (r = 0.407-0.482, all p < 0.001). There were significant strong positive correlations between mMRC score with CAT (r = 0.727) and SGRQ-c scores (r = 0.847), and CAT score with SGRQ-c score (r = 0.851) (all p < 0.001). CONCLUSIONS: In COPD patients, different severity of airflow limitation was not associated with significant differences in the mMRC, CAT, and SGRQ-c scores. Exacerbations were significantly more frequent in patients with very severe airflow limitation only. The correlation between airflow limitation with exacerbations, mMRC, and SGRQ-c was weak.

Clinical phenotypes and heath-related quality of life of COPD patients in a rural setting in Malaysia - a cross-sectional study.

BACKGROUND: The Spanish chronic obstructive pulmonary disease (COPD) guideline phenotypes patients according to the exacerbation frequency and COPD subtypes. In this study, we compared the patients' health-related quality of life (HRQoL) according to their COPD phenotypes. METHODS: This was a cross-sectional study of COPD patients who attended the outpatient clinic of the Serian Divisional Hospital and Bau District Hospital from 23th January 2018 to 22th January 2019. The HRQoL was assessed using modified Medical Research Council (mMRC), COPD Assessment Test (CAT), and St George's Respiratory Questionnaire for COPD (SGRQ-c). RESULTS: Of 185 patients, 108 (58.4%) were non-exacerbators (NON-AE), 51 (27.6%) were frequent exacerbators (AE), and the remaining 26 (14.1%) had asthma-COPD overlap (ACO). Of AE patients, 42 (82.4%) had chronic bronchitis and only 9 (17.6%) had emphysema. Of the 185 COPD patients, 65.9% had exposure to biomass fuel and 69.1% were ex- or current smokers. The scores of mMRC, CAT, and SGRQ-c were significantly different between COPD phenotypes (p <  0.001). There were significantly more patients with mMRC 2-4 among AE (68.6%) (p <  0.001), compared to those with ACO (38.5%) and NON-AE (16.7%). AE patients had significantly higher total CAT (p = 0.003; p <  0.001) and SGRQ-c (both p <  0.001) scores than those with ACO and NON-AE. Patients with ACO had significantly higher total CAT and SGRQ-c (both p <  0.001) scores than those with NON-AE. AE patients had significantly higher score in each item of CAT and component of SGRQ-c compared to those with NON-AE (all p <  0.001), and ACO [(p = 0.003-0.016; p = < 0.001-0.005) except CAT 1, 2 and 7. ACO patients had significantly higher score in each item of CAT and component of SGRQ-c (p = < 0.001-0.040; p <  0.001) except CAT 2 and activity components of SGRQ-c. CONCLUSIONS: The HRQoL of COPD patients was significantly different across different COPD phenotypes. HRQoL was worst in AE, followed by ACO and NON-AE. This study supports phenotyping COPD patients based on their exacerbation frequency and COPD subtypes. The treatment of COPD should be personalised according to these two factors.