Comparison of Continuous and Discrete Measurements of Dyspnea During Exercise in Patients With COPD and Normal Subjects

摘要: Study objectives The of this study were as follows: (1) to compare results the discrete and continuous methods for measuring breathlessness; (2) examine test-retest reliability; (3) test hypothesis that patients with COPD have higher slopes lower x-intercepts absolute thresholds power production, oxygen consumption ( o 2 ), minute ventilation independent variables breathlessness ratings dependent variable, compared healthy subjects. Design Visit 1 (familiarization) visit 3 (2 days apart) randomized assignment subjects rating during cycle ergometry. Setting Cardiopulmonary exercise laboratory in a university medical center. Participants Twenty-four (mean age, 66 ± 8 years [± SD]) 24 10 years). Interventions None. Measurements Ratings on Borg scale cue moving pressing computer mouse button indicate (discrete method) or by position adjust vertical bar change (continuous method). There no significant differences between 3. Although peak similar methods, both groups provided significantly more method. Patients exhibited slopes, x-intercepts, (breathlessness ≥ 0.5 [“just noticeable”] scale) production -breathlessness (p Conclusions Elderly are able use method successfully. Reliability is excellent methods. provides greater number over course exercise, allows clinician calculate an threshold just-noticeable differences. Regression parameters discriminate