Discriminating dyspnea related to lower extremity and whole body activity in COPD using the University of California San Diego Shortness of Breath Questionnaire

Purpose: To evaluate the ability of proposed University of California San Diego Shortness of Breath Questionnaire (SOBQ) subscores to discriminate changes in dyspnea related to Lower Extremity (LE) and Whole Body (WB) activity when compared to 6-Minute Walk (6MW) distance in persons with chronic obstructive pulmonary disease (COPD). Subjects: Twenty-four patients (4 men and 20 women) with moderate-to-severe COPD (FEV1 41.3 13% predicted [mean SD]) aged 68.1 8 years. Research Method: The SOBQ, providing only a total score, contains 24 items measuring perceptions of dyspnea for a variety of activities of daily living (ADLs). Three experts in pulmonary medicine and nursing classified each item into LE, upper extremity (UE), and WB activity subscores with the LE and WB subscores being the focus of this study. Using these proposed SOBQ subscores, a secondary analysis was performed using data obtained from an 8 week walking program. For the primary study, each subject completed both a SOBQ and 6MW at baseline, 4, and 8 weeks. The relationship between 6MW distance and proposed subscores at each time point was examined using Spearman’s rho correlation. Findings: Content validity was acquired for each proposed subscale with 100% concordance ratings among the pulmonary experts. SOBQ items 2, 3, 4, 5, and 7 compose the LE subscore and items 1, 10, 14, 15, 16, 18, 19, 20, 21 compose the WB subscore. At baseline, significant relationships were noted between 6MW distance and WB subscore (r= -0.523, p0.01) and total SOBQ score (r= -0.453, p<0.05). At 4 and 8 weeks, only WB subscore significantly correlated with 6MW distance (r= -0.508, p<0.05; r= -0.422, p