Dyspnea, Obstruction, Smoking, Exacerbation Index, and Chronic Obstructive Pulmonary Disease Test Score: Correlation in Predicting Outcomes in Patients with Chronic Obstructive Pulmonary Disease Exacerbations

ABSTRACT

Objectives: Chronic obstructive pulmonary disease (COPD) being a disease with systemic consequences necessitate the use of multidimensional indices for a comprehensive assessment of the disease's impact including the future risk of exacerbations and mortality. To study the role of dyspnea, obstruction, smoking, and exacerbation (DOSE) index as a predictor of future disease severity and its correlation with chronic obstructive pulmonary disease test (CAT) score. Measurements and results: A total of 60 inpatients with COPD exacerbations were followed up for 6 months to record the number of exacerbations of COPD. The DOSE index and CAT score were calculated after stabilization within 48 hours of admission, at 1 week, and again at 6 months. The mean difference between DOSE index score at admission and at 1 week was 1.382 � 0.561 and at admission and at 6 months was 2.15 � 0.988, both being statistically significant (p < 0.001). A high DOSE index score (?4) was associated with a greater risk of 2 or more exacerbations [odds ratio (OR), 12 (3.09�.60) and risk estimate, 3.75 (1.53�17)]. For the prediction of exacerbations, the area under the curve (AUC) was larger for the DOSE index (0.854) than the global initiative for chronic obstructive lung disease (GOLD) stage (0.789), p < 0.001 for both. Furthermore, DOSE index correlated significantly with the CAT score, an established health status measure, at all stages of disease severity; at the onset of exacerbation (r = 0.719, p < 0.001), after stabilization at 1 week (r = 0.736, p < 0.001) and at 6 months (r = 0.884, p < 0.001). Conclusion: The DOSE index is a simple, practical multidimensional grading tool for assessing current symptoms, health status, and future risk in COPD and acts as a guide to disease management as its component items can be modified by interventions. Its correlation with CAT, a well-known score is a novel observation, which further corroborates the validity of the DOSE index.