Rationale: In COPD, hospital-based pulmonary rehabilitation can improve symptoms, functional status, and quality of life and decrease unscheduled physician visits, emergency room visits, hospitalizations, and possibly, mortality. Despite the well documented efficacy, hospital-based rehab remains inadequate due to insufficient access, acceptance and sustainability. This has triggered a growing interest in home-based rehab programs. Patients enrolled in home-based programs, however, may exercise at low intensities to avoid dyspnea/fatigue, limiting the potential benefits of exercise training. Accordingly, it is essential to develop innovative home-based programs that decrease exercise-induced dyspnea and fatigue while ensuring sufficient exercise intensity to produce sustainable physiologic benefit. Recent data suggest that rhythmically enhanced stimulation (RAS) using music may constitute such an innovative strategy. Music can diminish exercise-induced dyspnea/fatigue allowing patients to tolerate more challenging physical activity and obtain a greater benefit from rehab. Music also can induce entrainment of motor responses such as walking. We thus plan to capitalize on both the sensorimotor coupling of gait with RAS-enhanced music and the mitigating effect of music over exercise-induced dyspnea/fatigue. Specifically, we propose to compare the efficacy of a 12-week, home-based exercise program augmented by patient-tailored, RAS-enhanced music to a 12-week traditional home-based exercise program in patients with COPD. Hypothesis: (H1) Compared to patients randomized to a home-based, exercise program without music (control group), patients randomized to a home-based, exercise program augmented with RAS- enhanced music (intervention group) will demonstrate (H1a, primary hypothesis) greater increase in 6-minute walk distance, (H1b) greater increase in walking time on a constant-load treadmill test protocol, (H1c) reduced dyspnea during a constant-load treadmill test protocol, and (H1d) greater increases in health-related quality of life. In addition (H2), they will accumulate greater volume of physical activity (actigraphy) and (H3) will better sustain these benefits over time. Lastly (Explorative Objective), we will assess the mechanistic impact physiological and psychological phenotype and clinical factors on responsiveness to rehabilitation (duration constant-load treadmill test) achieved with and without concurrent use of RAS-music. Methods: The proposed study is a randomized, controlled clinical trial in which 170 patients will be randomized into a home-based, exercise program without music or a home-based exercise program augmented with RAS-enhanced music. Patients will receive 12-weeks of home-based training per group assignment (at least three times weekly) followed by 12-weeks of follow-up to assess the sustainability of our novel intervention. Testing will be carried out at baseline and at 6, 12 and 24 weeks. Testing will include pulmonary function test, 6-minute walk tests, constant- load treadmill test, physical activity quantification, measurements of dyspnea, quality of life, and objective quantification of quadriceps dimensions (ultrasonography) and strength/fatigue (magnetic stimulation of the femoral nerve). Analysis: In the principal analysis of the primary outcome measure (6-minute walk distance) we will use a mixed-model analysis that includes treatment, time and treatment-by-time interaction terms. This model will automatically account for missing data?where missing at random is assumed. We will conduct a sensitivity analysis based on the results of the mixed model analysis to determine which other assumptions regarding missing data might produce different results. One component of the sensitivity analysis will include adjustment for baseline demographic and health covariates. A linear regression model and a mixed model ANOVA will be used to assess the impact of clinical confounders (Explorative Objective). Scientific contribution: These data will provide a solid foundation to determine the physiologic impact of our rehab strategy. This innovative, practical and economical pulmonary rehabilitation strategy has the potential to create a paradigm shift in the care of the many veterans with COPD who have no access to pulmonary rehabilitation.
to the VA: The VA cares for nearly one million veterans with COPD at a cost of more than $5.5 billion annually. COPD profoundly impairs quality of life as it limits ability to work, to maintain physical exertion and to engage in social activities. Hospital-based rehab can decrease the need for inpatient and outpatient medical care and can improve exercise capacity, quality of life and, possibly, decrease mortality. Unfortunately, access to hospital-based VA rehab is insufficient and, over time, the few veterans who attend experience progressive loss of functional gains. We reason that our proposed home-based exercise program augmented by patient-tailored, RAS-enhanced music will overcome the many limitations of hospital-based rehab. Through our innovative program, we expect to enhance the benefits of rehab and better maintain them over time. The easy applicability of our innovative, accessible and economical program has the potential to modify the spiraling pattern of increasing disability and reduce health-care cost and mortality in veterans with COPD.
