Background: Numerous instruments have been developed to examine the impact of activities on breathlessness. The primary purpose of this study was to examine the validity and responsiveness of the self-administered computerized (SAC) versions of the multidimensional baseline dyspnea index (BDI) and the transition dyspnea index (TDI).
Methods: Sixty-five patients with COPD who complained of exertional breathlessness were evaluated at an initial visit and after receiving standard therapy at two academic medical centers. Dyspnea scores from the SAC versions were compared with those obtained with the Medical Research Council (MRC) scale and with the original interview versions of the BDI and TDI.
Results: At the initial visit, all three dyspnea instruments showed similar correlations among themselves and with lung function. At the follow-up visit (mean [± SD] time after initial visit, 48 ± 16 days), breathlessness scores were improved on all three instruments. Correlations were consistently higher for both versions of the TDI, and changes in lung function compared with corresponding values for ΔMRC scale. Although 55% of patients reported no change in breathlessness on the MRC scale following treatment, the mean SAC and interview TDI scores were increased by 1.0 ± 2.4 and 1.4 ± 2.5, respectively, in these same patients.
Conclusions: Both versions of the BDI and the MRC scale showed concurrent validity at the initial visit. The SAC TDI demonstrated responsiveness to standard therapy that was comparable with the findings of the interview TDI, but was better than that recorded with the MRC scale. The advantages of the SAC TDI include a patient-reported score on a continuous scale using computer technology.