Methods: This was a cross-sectional study of patients with COPD attending the respiratory medicine clinic of University of Malaya Medical Centre from 1 June 2017 to 31 May 2018. Disease-specific HRQoL was assessed by using the COPD Assessment Test (CAT) and St George's Respiratory Questionnaire for COPD (SGRQ-c).

Results: Of 189 patients, 28.6% were of non-exacerbator phenotype (NON-AE), 18.5% were of exacerbator with emphysema phenotype (AE NON-CB), 39.7% were of exacerbator with chronic bronchitis phenotype (AE CB), and 13.2% had asthma-COPD overlap syndrome phenotype (ACOS). The total CAT and SGRQ-c scores were significantly different between the clinical phenotypes (P<0.001). Patients who were AE CB had significantly higher total CAT score than those with ACOS (P=0.033), AE NON-CB (P=0.001), and NON-AE (P<0.001). Concerning SGRQ-c, patients who were AE CB also had a significantly higher total score than those with AE NON-CB (P=0.001) and NON-AE (P<0.001). However, the total SGRQ-c score of AE CB patients was only marginally higher than those who had ACOS (P=0.187). There was a significant difference in the score of each CAT item (except CAT 7) and SGRQ-c components between clinical phenotypes, with AE CB patients recording the highest score in each of them.