Longitudinal Changes in Patient-reported Dyspnea in Patients with COPD

Background: Although guidelines recommend monitoring symptoms in patients with chronic obstructive pulmonary disease (COPD), there is limited information on the longitudinal changes in patient-reported dyspnea (PRD) related to activities of daily living. The hypothesis was that PRD scores on the modified Medical Research Council (mMRC) scale, the self-administered computerized (SAC) transition dyspnea index (TDI), and the University of California San Diego Shortness of Breath questionnaire (UCSD SOBQ) would demonstrate progression over two years. Methods: Observational cohort study of symptomatic patients with stable COPD evaluated every 6 months for 2 years. Patients rated the impact of activities of daily living on dyspnea using three patient-reported instruments presented in random order, and then performed post-bronchodilator (pBD) spirometry. Results: Seventy patients (37 female/33 male; age: 66 +/- 9 years; and pBD forced expiratory volume in one second [(FEV1): 51 +/- 16 % predicted] participated. Using fixed effects regression modeling, there was significant worsening in the PRD scores with the SAC TDI (-0.9 +/- 2.7; p = 0.03) and UCSD SOBQ (+5.7 +/- 18.3; p = 0.001), but not with the mMRC scale (p = 0.52). Both pBD FEV1 (p = 0.19) and pBD forced vital capacity (p = 0.65) were unchanged. Conclusions: Multidimensional instruments (SAC TDI and UCSD SOBQ) demonstrated the frequently observed decline in PRD experienced by patients with COPD. The progression in PRD occurred despite stable lung function. Monitoring PRD provides unique clinical information and should be considered along with measuring lung function to assess patient status over time.