Purpose: Composite measures have potential to account for many of the facets of disease in chronic obstructive pulmonary disease (COPD). The purpose of this study was to investigate the relationship between the DOSE (Dyspnea, Obstruction, Smoking, Exacerbation) Index which is a multi-component assessment tool and handgrip and respiratory muscle strength, activities of daily living (ADL) and health-related quality of life in patients COPD. Methods: Forty-five patients with COPD (30 males, 15 females, mean FEV 1 =50.60±16.00%) were included. The DOSE Index was calculated using the modified Medical Research Council dyspnea scale, obstruction level, smoking status, and exacerbation rate. Inspiratory and expiratory muscle strength (MIP and MEP) was measured using a mouth-pressure device. Handgrip strength was determined using hand dynamometer. Activities of daily living were evaluated using the London Chest Activity of Daily Living Scale (LCADL), and quality of life was assessed using the diseasespecific COPD Assessment Test (CAT). Results: The DOSE Index score was related with handgrip strength (r=-0.388, p=0.009), MIP (r=-0.323, p=0.033), LCADL-physical activity score (r=0.314, p=0.038), LCADL-leisure activities score (r=0.397, p=0.008), and CAT score (r=0.435, p=0.003). Conclusion: Increased multi-component disease severity is related to decreased handgrip and respiratory muscle strength, physical activity and leisure time activities of daily living, and worse health-related quality of life in COPD patients. The DOSE Index, a simple disease severity assessment tool, is a convenient and practical tool for assessment in pulmonary rehabilitation programs.