Evaluating symptoms in chronic obstructive pulmonary disease: validation of the breathlessness, cough and sputum scale©

Abstract

This study examined the reliability and validity of a new measure for evaluating symptoms in patients with chronic obstructive pulmonary disease (COPD): the Breathlessness, Cough and Sputum Scale (BCSS©). Designed as a daily diary, the BCSS is a patient-reported outcome measure that asks patients to rate the severity of the three symptoms, each on a 5-point scale; higher scores indicate more severe symptoms. Item scores are summed to yield a total score. Secondary analysis of data were from two multinational trials (n=629; 765). The BCSS item and total scores exhibited evidence of internal consistency (α = 0·70 daily; 0·95 to 0·99 over time) and reproducibility (ICC = 0·77 to 0·88). Correlations (r) with pulmonary function (FEV₁ % predicted, PEF) were −0·01 (n.s.) to −0·36 (P < 0·001). Correlations with the St George's Respiratory Questionnaire total and SF-36 Physical Functioning subscale were 0·44 to 0·59 (P < 0·001). Breathlessness and total scores differentitated patients by disease severity (P < 0·01) and rescue medication use (P < 0·01). Cough, sputum, and total scores increased with sputum volume (r=0·27, 0·30, 0·31; P<0·001). Patients for whom treatment was moderately or highly effective reported significant improvements in BCSS scores (P < 0·0001).

Results suggest that the BCSS is a reliable, valid, and responsive patient-reported outcome measure of symptom severity in patients with COPD.