Grant: Travel Awards - Institute Community Support

Breathlessness is the most common and troublesome symptom experienced by people with chronic obstructive pulmonary disease (COPD). The 3-minute constant-rate stair stepping (3MST) & shuttle walking tests (3MWT) were recently developed and validated as standardized tests to evaluate breathlessness on exertion in the clinical care setting of COPD. While research suggests that these tests can detect acute changes in breathlessness after the use of common respiratory medications, it is not yet known whether they can detect changes in breathlessness following pulmonary rehabilitation (PR). In addition, the change in breathlessness that would be considered clinically important for a COPD patient during these tests is not yet known. Therefore, we evaluated the responsiveness of the 3MST & 3MWT to identify changes in breathlessness on exertion in 37 adults living with COPD after an 8 to 12-week PR program. Patients were asked to rate their levels of breathlessness on a 10-unit scale at the end of the 3MST & 3MWT before and after PR. Results of all pooled participants showed no statistically significant change in levels of breathlessness after the 3MST or 3MWT following PR. However, when the analyses were limited to patients whose level breathlessness was rated as moderately severe (3 or higher on the 10-point scale) at the end of these tests prior to the start of PR, the changes in breathlessness were statistically significant. We also estimated that the minimal clinically important change in breathlessness ratings was 0.9 out of 10 units for the 3MST and 1.0 units for the 3MWT. The preliminary results of this project suggest that the 3MST and the 3MWT are responsive to identify changes in breathlessness on exertion following PR in COPD patients, but only if their baseline levels of breathlessness are at least moderately severe. In addition, a change in self-reported breathlessness of 0.9 units or more during the 3MST and 3MWT are clinically meaningful to people with COPD.