Evaluation of correlation of BODE index with health-related quality of life among patients with stable COPD attending a tertiary care hospital

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by progressive deterioration of respiratory function along with systemic effects which have a great impact on health-related quality of life (HRQoL). Classification of severity of airflow limitation in COPD does not represent the clinical consequences of COPD. Hence, combined COPD assessment should be preferred. BODE index (Body mass index, Airflow obstruction, Dyspnea and Exercise capacity) has recently been proposed to provide useful prognostic information. OBJECTIVES: To find out correlations between the BODE index and HRQoL, and between GOLD classification of COPD severity and HRQoL in stable COPD patients, and to compare between these two correlations. MATERIALS AND METHODS: A longitudinal observational study was carried out with 114 stable COPD patients recruited over 10 months at the outpatient clinic of a tertiary care hospital in Kolkata, India. Patients were classified according to GOLD classification of severity of airflow limitation after performing spirometry. BODE index was calculated for each patient. Saint George's Respiratory Questionnaire (SGRQ) was used to assess the HRQoL. RESULTS: BODE scores were categorized into four quartiles, quartile one to four with scores of 0-2, 3-4, 5-6 and 7-10, respectively. Higher BODE quartiles were associated with higher total SGRQ scores and SGRQ subscale scores (symptom, activity and impact). Very strong correlations were found between BODE quartiles and total SGRQ scores (P = 0.914; P < 0.01). In contrast, GOLD classes showed moderate correlation with total SGRQ scores (P = 0.590; P < 0.01). CONCLUSIONS: BODE index was strongly correlated with the HRQoL in stable COPD patients and it was better than GOLD classes of COPD severity to reflect the health status in patients with stable COPD.