Responsiveness of three instruments to assess self-reported functional status in patients with COPD.

The study aimed to compare the responsiveness of three instruments to assess self-reported changes in functional status after exercise training in patients with COPD: Pulmonary Functional Status and Dyspnea Questionnaire -modified version (PFSDQ-M), London Chest Activity of Daily Living (LCADL) and Medical Research Council scale (MRC). Twenty-two patients (11 female, 66[62-71] years, FEV1 42[33-61]%predicted) participated in a 3-month high-intensity exercise program. The three instruments were applied pre- and post-program, as well as assessment of lung function, muscle strength, exercise capacity (6-minute walking test, 6MWT) and quality of life (St. George's Respiratory Questionnaire, SGRQ). SGRQ, 6MWT and quadriceps femoris, biceps and triceps brachialis strength improved significantly after the program (p < 0.05 for all). Training also yielded significant improvement in the LCADL total score and self-care, domestic and leisure domains and in the PFSDQ-M 'change in activities' domain, with no improvement in the MRC (p = 0.11). Calculation of effects sizes also indicated higher responsiveness in the LCADL than the other instruments. There were no significant correlations between changes in the three instruments and changes in lung function, SGRQ or 6MWT. In conclusion, PFSDQ-M's 'change in activity' domain and specially the LCADL (to a higher extent) showed responsiveness to detect changes in functional status after three months of high-intensity exercise training in patients with COPD, whereas the MRC scale did not. In this population, the improvement in functional status was not related with improvement in exercise capacity, lung function or quality of life.

Step counting and energy expenditure estimation in patients with chronic obstructive pulmonary disease and healthy elderly: accuracy of 2 motion sensors.

OBJECTIVE: To compare the accuracy of 2 motion sensors (a pedometer and a multisensor) in terms of step counting and estimation of energy expenditure (EE) in patients with chronic obstructive pulmonary disease (COPD) and in healthy elderly. DESIGN: In this descriptive study, all participants wore both motion sensors while performing a treadmill walking protocol at 3 different speeds corresponding to 30%, 60%, and 100% of the average speed achieved during a six-minute walk test. As criterion methods, EE was estimated by indirect calorimetry, and steps were registered by videotape. SETTING: Research laboratory at a university hospital. PARTICIPANTS: Patients with COPD (n=30; 17 men; mean age +/- SD, 67+/-8 y; mean forced expiratory volume in the first second [FEV(1)] predicted +/- SD, 46%+/-17%; mean body mass index [BMI] +/- SD, 24+/-4 kg.m(2)) and matched healthy elderly (n=30; 15 men; mean age +/- SD, 68+/-7 y; mean FEV(1) predicted +/- SD, 104%+/-21%; mean BMI +/- SD, 25+/-3 kg.m(2)). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Step counting and EE estimation during a treadmill walking protocol. RESULTS: The pedometer was accurate for step counting and EE estimation in both patients with COPD and healthy elderly at the higher speed. However, it showed significant underestimation at the 2 slower speeds in both groups. The multisensor did not detect steps accurately at any speed, although it accurately estimated EE at all speeds in healthy elderly and at the intermediate and higher speeds in patients with COPD. CONCLUSIONS: In both patients with COPD and healthy elderly, the multisensor showed better EE estimates during most walking speeds than the pedometer. Conversely, for step counting, accuracy is observed only with the pedometer during the higher walking speed in both groups.