Background: Although clinicians often rely on patients' retrospective reporting of dyspnea, it is not known if dyspnea scores recalled after exercise are equivalent to dyspnea scores during exercise. The objective of this study was to determine whether patients could accurately recall after exercise the maximum ratings of the intensity of dyspnea and the anxiety associated with it that they experienced during exercise.
Methods: Forty-nine patients with chronic obstructive pulmonary disease (COPD) (forced expiratory volume in 1 second 0.92 +/- 0.23 L) participating in a randomized clinical trial of the impact of coached versus monitored exercise training on dyspnea rated dyspnea intensity (shortness of breath [SOB]) and dyspnea-related anxiety (DA) on a visual analog scale every 2 minutes during treadmill exercise. After each of 12 training sessions each subject was asked to rate the worst level of the two sensations that they recalled having experienced during exercise.
Results: For the groups as a whole, actual maximum scores for SOB and DA during exercise were highly correlated with recalled maximum values after exercise (r > or = 0.85, P < 0.0001) and the average differences were small (0-10.9 mm on a 200-mm scale). However, individual variation was substantial, limiting predictability for individual ratings.
Conclusions: After exercise, patients with COPD as a group can accurately recall the worst SOB and DA that they experienced during exercise. This finding supports the further study and use of retrospective symptom ratings as a method for dyspnea assessment during exercise training in pulmonary rehabilitation.