Gender Moderates the Effects of Exercise Therapy on Health-Related Quality of Life Among COPD Patients

Study objectives: To determine whether long-term treatment with exercise therapy results in more favorable, disease-specific, health-related quality of life (HRQL) compared with short-term treatment with exercise therapy; and to determine whether there are gender differences in disease-specific HRQL among individuals randomized into the two treatment groups. Design: Randomized clinical trial. Setting: Center-based exercise therapy unit at a university. Participants: One hundred forty patients with COPD; 118 completed trial. Interventions: Short-term exercise therapy (3 months); long-term exercise therapy (18 months). Measurements: Chronic Disease Respiratory Questionnaire (CRQ). Results: After 3 months of treatment, there were significant improvements in all CRQ scores for men and women (p < 0.01), and for the total sample (p < 0.01). At 18 months, individuals randomized into the long-term group had significantly more favorable scores than the short-term group for dyspnea (p 5 0.03), fatigue (p < 0.01), emotional function (p 5 0.04), and mastery (p 5 0.04). However, these effects were moderated by gender. That is, men in the long-term group reported significantly more favorable scores than men in the short-term group for dyspnea (0.04), fatigue (p < 0.001), emotional function (p 5 0.02), and mastery (p 5 0.02). At the 18-month assessment, there were no differences between long-term and short-term exercise therapy for women on any of the subscales of the CRQ. Conclusions: Taken collectively, the CRQ data demonstrate that long-term exercise therapy has little added benefit for women over short-term exercise therapy; however, men derive significant benefits from extended training. (CHEST 2001; 119:70‐76)