Occurrence of Anxiety and Depression among Stable COPD Patients and its Impact on Functional Capability

Introduction: Anxiety and depression are important but often under-diagnosed co-morbid conditions in patients with Chronic Obstructive Pulmonary Disease (COPD) which may affect the functional capacity of the patients. Aim: To find out the proportion of depression and anxiety among stable COPD patients using a validated questionnaire suitable for use in clinic and the factors affecting their reduced functional capability as assessed by six-minute walk test. Materials and Methods: This was a descriptive cross-sectional study. Seventy five patients diagnosed with stable COPD in outpatient Department of Pulmonary Medicine in a tertiary care hospital, satisfying all inclusion criteria, were included in the study. They were examined clinically, categorized as per Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity assessment guideline and interviewed by designated interviewer using validated questionnaire for depression (Hamilton depression rating scale, HAM-D) and anxiety (State Trait Anxiety Inventory, STAI). The functional exercise capacity of the patient was assessed by six-minute walk test. Statistical analysis was performed using Minitab software (version16.1). Results: Among 75 stable COPD patients (68 male, 7 female), majority (32 out of 75) had both depression and anxiety, while only anxiety or depression was present in 9 each. The patients with depression had no significant difference in six-minute walk distance, change in heart rate and respiratory rate (p = 0.4186, 0.219 and 0.41 respectively) as compared to those without depression, but were found to be more dyspnoeic at the end of the test (p= 0.003). There was also no significant difference in walk distance in patients with high STAI score as compared to those with low STAI score (p= 0.276). Conclusion: Both anxiety and depression were present in majority of the stable COPD patients. The presence of these co-morbid conditions had no significant effect on the functional status of the patients in the form of reduced six-minute walk distance, though they were more symptomatic than those without these co-morbidities.