The ability to enjoy or even tolerate many simple activities usually progressively deteriorates because of dyspnea in individuals with chronic obstructive pulmonary disease (COPD). Numerous studies have identified COPD as a major cause of disability and death, as well as an economic burden on the health care system.1–4 Moreover, as patients with COPD become less active, dyspnea worsens with loss of basic mobility functions, often causing dependence and depression.2,5
Pulmonary rehabilitation programs, which may be conducted in a number of settings including inpatient, outpatient, community, and home, offer an approach for reversing the progressive disability of COPD.1,6 The major components of pulmonary rehabilitation include education, self-management support, exercise/physical activity training, and psychosocial support.7,8 Evidence on the efficacy of these programs has grown rapidly over the past 3 decades, and the results provide strong evidence that pulmonary rehabilitation programs regardless of setting improve respiratory symptoms, quality of life, and functional (eg, 6-minute walk) and maximal exercise performance.9–11 However, few studies have focused on patients with the most severe impairment causing them to be homebound.12–14 The purpose of this pilot study was to examine the effectiveness of in-home rehabilitation for homebound patients with COPD and to compare the relative effects of 2 different rehabilitation strategies.
Paradigm Rehab and Nursing is a home health agency operating in the northeast region of Texas. The agency includes 18 physical therapists, 5 occupational therapists, and 35 nurses and cares for more than 2400 patient-episodes per year. This agency has a large number of full-time professionals who maintain consistent caseloads and meet weekly for case conferences. For this study, case conference also served as a forum to update and answer questions on the COPD protocols. Specific intervention flow sheets were maintained on each study patient, designed to record each step of the care provided. The use of these flow sheets helped ensure reliable service delivery between practitioners.
Participants and Informed Consent
Patients with COPD referred by their physician to the agency for home health services were evaluated for eligibility by agency staff, using standardized inclusion and exclusion criteria. The inclusion criteria were as follows: (1) age 40 years and older, (2) physician-diagnosed COPD, (3) forced expiratory volume in the first second of expiration (FEV1)/forced vital capacity less than 70%, and (4) dyspnea level that limits ability to leave home without assistance of another person or requires use of assistive device. Exclusion criteria included the following: (1) uncontrolled hypertension, angina, heart failure, or psychiatric illness; (2) dementia; (3) life expectancy less than 12 months; (4) inability to ambulate; (5) inability to obtain supplemental oxygen if ordered by a physician. If a patient was determined to be eligible, he or she was provided standardized informational materials about the study, and if interested, informed consent was obtained before any study procedures were conducted. This study was approved by The University of Texas Health Science Center at Tyler institutional review board.
Data Collection and Outcome Measures
Data were collected in each patient's home at baseline before starting the intervention and after 2 subsequent 8-week intervals (ie, after completion of the 8-week intervention) and at 16 weeks. Trained research assistants, blinded to group assignment, collected baseline and follow-up data. The baseline data were collected using a standardized questionnaire that included demographic information, smoking history, Modified Medical Research Council (MMRC) dyspnea scale,15 self-report of comorbid illnesses, Geriatric Depression Scale (GDS),16 and the Chronic Respiratory Questionnaire (CRQ).17
The MMRC dyspnea scale was used to classify the severity of dyspnea in the participants prior to the study. The MMRC is a 0 to 4 scale, with 0 indicating dyspnea only with high level of activity and 4 indicating most severe dyspnea that prevents the individual from leaving home. The scale has high reliability with intraclass correlation of 0.82 and interobserver percent agreement of 96% (κ statistic = 0.92).18 Moreover, evidence for the validity of the scale is supported by the significant inverse association between the level of dyspnea on the MMRC scale and severity of lung function impairment.18
Morbidity and mortality among patients with COPD are commonly associated with the number of comorbid conditions. Therefore, the number of comorbid illnesses is one measure used to describe the level of morbidity in the sample population. The number of illnesses was measured by self-report of physician diagnoses, using a standardized questionnaire modeled after the diagnoses used to estimate the Charlson comorbidity index, which is a validated predictor of mortality.19
The GDS16 was developed to screen elderly patients for depression in the primary care setting, and the reliability and validity of the instrument has been examined in different older populations. The GDS is composed of 15 questions with yes/no responses. Each affirmative response is scored 1 point, and a score of 0 to 5 indicates none to low-level depression, 6 to 10 points suggests mild to moderate depression, and 11 to 15 points is considered severe depression. Psychometric studies have demonstrated the reliability and validity of the GDS and suggest a cutoff score of 5 to 6 to identify individuals with significant clinical depression.16 Among community-dwelling primary care elderly patients who are functionally impaired, Friedman et al16 report found moderate internal reliability with Cronbach α of 0.75. In this same study, criterion and construct validity were assessed using interview-based measure of depression and correlations with several measures of self-reported depression. The criterion validity using a cutoff score of 5 to estimate depression had a sensitivity and specificity of 89.5% and 65.3%, respectively.16
The CRQ is a 20-item disease-specific quality of life measure used extensively in previous studies of pulmonary rehabilitation and comprised of 4 domains: dyspnea, fatigue, emotion, and mastery.17 Scoring is based on the average response in each domain, rated on a scale from 1 to 7 with a rating of 1 the highest level of limitation and 7 no limitation. The CRQ has been demonstrated to be reliable, valid, and responsive to change in previous trials with a change of 0.5 on any domain subscale considered the minimal clinically important difference (MCID).17
The CRQ was chosen because it is one of a few disease-specific quality-of-life instruments that is both valid and responsive11,17 and it has been used as a primary outcome measure in a large number of pulmonary rehabilitation studies.11 Correlation of test-retest reliability has ranged from 0.73 to 0.95 for all domains and Cronbach α values for internal consistency for dyspnea domain have ranged from 0.53 to 0.84.11 Construct validity has been examined using correlation with VO2max (0.48), FEV1 (0.34–0.66), 6-minute walk (0.26–0.52), and other self-reported instruments (0.20–0.77) in cross-sectional and longitudinal studies.11 The MCID for each of the CRQ domains is 0.5.
In addition to the questionnaire measures, spirometry parameters were obtained using handheld spirometers and functional status was assessed using the distance walked in 2-minute walk (or 2-minute walk test [2MWT]).20 For this test, patients were instructed to walk as far as they could in 2 minutes at their own pace over a flat course, with the distance measured to the nearest meter.20 The 2MWT was used instead of the 6-minute walk traditionally used in studies of pulmonary rehabilitation because of the lower cardiopulmonary endurance found in our older and more debilitated COPD participants.20,21 The 2MWT has been shown to be both reliable and valid for patients with moderate to severe COPD. 20,21 Test-retest reliability is high, with intraclass correlation of 0.99. Validity of the test is supported by correlations with the 6-minute walk distance (0.937) and maximum oxygen uptake (0.555). While an MCID has not been established for the 2-minute walk, the MCID for this test was estimated as one-third (8.7–11.7 m) of the MCID for the 6-minute walk (26–35m) because of the correlation between the 2 tests.22
The main outcome measures at 8 and 16 weeks included the CRQ-dyspnea domain, GDS, and 2-minute walk distance.
After obtaining informed consent and with the aid of a computer random number generator, the study coordinator randomized participants into the 2 intervention groups. Group assignment was then communicated to home health staff responsible for conducting the intervention protocols.
All patients received 24 home visits over an 8-week period that comprised COPD self-management education and either aerobic conditioning (group A) or functional strengthening (group B) (Table 1). Because patients were referred for home health services, it was not possible to have a control group without some form of active intervention. The rationale for the 2 interventions was derived from the pulmonary rehabilitation literature, which suggests that aerobic exercise provides more consistent benefit in quality of life and walking distance than resistance exercise.23 With increasing evidence available on strength training for older adults, including a recent white paper review, resistance exercise appeared to have potential for functional gains patients with COPD.24 In addition, the American College of Sports Medicine (ACSM) guidelines recommend resistance training to counteract the skeletal muscular losses that occur with COPD.25 Unlike outpatient programs for COPD that can include several modes of exercise, homebound patients' initial tolerance for exercise is much lower and therefore exercise is more likely to produce change if focused in one area.
The group-specific exercise protocols were delivered during 20 physical therapy visits for group A and 16 physical therapy visits for group B. Vital signs were measured before starting each protocol. Aerobic conditioning for group A included timed warm-up of active range of motion and stretching upper and lower extremities, ranging from 5- to 10-minute duration with time recorded on flow sheet. The aerobic exercise consisted of supervised walking or restorator exercise, or a combination of the 2. Restorator exercise uses freestanding pedals for stationary cycling that can be placed on the floor in front of a chair. The patient is instructed to pedal continuously at a pace they could continue over several minutes. The goal of the aerobic exercise was to complete a total of 30 minutes of total time of supervised walking and restorator exercise, although this time frame was not always feasible for patients and had to be progressed as possible. The ACSM guidelines state that in cases of COPD, patients may tolerate only a few minutes of exercise at a time,25 which was the case for some patients in our study. The 30-minute goal was indicated on the therapy flow sheet, where all activities were timed and recorded during each session. The aerobic exercise was always self-paced, with emphasis on increasing total time of exercise for endurance; therefore, progression was based on exercise duration rather than intensity.
Heart rate was monitored so that individuals with tendency for higher heart rates were stopped if increases occurred going above age-adjusted norms as given in the ACSM guidelines.25 Individuals in our study were more likely to have dyspnea as the limiting factor, and timing stopped and rest was allowed with patient complaints of dyspnea or oxygen saturation below 90%. Total exercise time recorded did not include rest periods. For some patients, especially those whose heart rate response was decreased with medications, the 20-point perceived exertion scale of Borg25 was used. The 20 points run from 0 to 5 “light exertion” to 18 to 20 “very hard,” with the patient instructed to work to no more than “somewhat hard (13 points)” to “hard (15 points).” To focus on improving duration, strategies to increase total exercise time sometimes included combining restorator and walking in intervals, or walking a maximal amount of time varying speeds, and then adding time with the less intensive restorator activity. Following the aerobic exercise, a cooldown of 3 to 8 minutes of light movement and stretching was done, with monitoring of vital signs, until heart rate and oxygen saturation returned to initial levels.
Strengthening exercises for group B included timed warm-up that was the same as for group A. Following warm-up, strengthening exercises were selected for lower body and postural muscles, usually including 12 to 18 trunk and multijoint extremity exercises. For example, lower body strengthening exercises included repeated sit to stand with slow descent, partial squats, static lunges, heel raises, stepping up and down from 4 to 6 inch step, and variations of straight leg raises for hip flexion, abduction, and extension. Resistance was added with not only elastic bands or light weights but also body weight for functional mobility exercise. Examples of postural exercise included recruitment of posterior shoulder girdle with rowing or bow and arrow movements against elastic resistance or against gravity with weights, rotator cuff recruitment, overhead pull-downs, and pushing activities to recruit abdominals. Balance activities such as trunk circles or weight shifting with reaching also targeted postural muscles. The strengthening exercises focused on increasing repetitions as opposed to increasing amount of resistance, working up to a total of at least 30 minutes of exercise. Although both amount of resistance and number of repetitions were recorded, again exercise duration was the primary focus for progression. Cooldown was performed at the conclusion of exercise in the same manner as that for group A individuals. Tolerance of exercise intensity varied between individuals in both groups, so intensity was adjusted to patient capability.
Exercise tolerance was determined by heart rate and oxygen saturation responses that were monitored throughout the exercise, and rest periods provided as needed for recovery. For both groups, oxygen saturation was monitored throughout exercise, and activity was modified when needed. For those patients using supplementary oxygen, flow was titrated to maintain oxygen saturation at 90% or more. Therapists also addressed safety concerns that included breathing techniques, symptom control, balance, and fall prevention on each visit.
Both groups concurrently received COPD self-management education delivered in 6 modules. To ensure consistent implementation of the intervention protocols among the various home health physical therapists and nurses, everyone was trained in both protocols. Home visit assessments consisted of resting blood pressure, heart rate and oxygen saturation levels, a short description of each activity during the visit, duration of each activity, and repeat vital signs immediately at the completion of the session.
During nursing visits, all participants received nursing assessments and 6 COPD self-management education modules, which were supplemented by written materials. Group A received 4 nursing visits, and group B received 8 nursing visits. Nursing assessments included review of safety concerns including fall prevention, medication use, and oxygen use when applicable. The COPD self-management modules included basic information about COPD such as breathing and coughing techniques; energy conservation for activities of daily living; relaxation techniques; controlled breathing when symptoms occur; action plan for acute exacerbations; nutrition; smoking cessation; sleep habits; healthy lifestyle; and long-term home oxygen therapy.
Comparison of clinical and statistical significance was conducted between and within the 2 groups at baseline, 8 weeks, and 16 weeks. Criteria for determination of clinical significance were previously described. Because the distributions of the outcome variables were not normally distributed, we used median and interquartile ranges to report central tendency and dispersion values, respectively. Moreover, comparisons of statistical significance were made using nonparametric methods across the 3 time periods (baseline, 8 weeks, and 16 weeks) as well as pair-wise contrasts at each time period.
Statistical tests were conducted using the Friedman test for each CRQ domains, GDS, and 2-minute walk distance. Additional post hoc analyses were applied using the Wilcoxon signed-rank test in instances where statistical significance was found via the Freedman method. Pair-wise comparisons between groups were also made at each time period for each outcome variable. All statistical comparisons were considered statistically significant at P < .05.
Of 41 patients (20 women, 21 men) enrolled, 24 completed the 8-week intervention period with 13 randomized to group A and 11 to group B (Table 2). On average, the 17 patients who withdrew were younger (70.1 vs 74.0 years) and had more severe dyspnea than the 24 patients who completed the interventions (MMRC: 3.4 vs 2.8). While all patients who completed the intervention reported being current or former cigarette smokers, only 12% were current smokers. Also, patients assigned to group A tended to be younger and female compared with group B (Table 2) but had similar levels of dyspnea, number of comorbidities, and severity of impairment measured by FEV1 and 2-minute walk distance.
Chronic Respiratory Questionnaire Scores by Domain
Overall, there were no statistically significant differences between the 2 groups for any of the 4 CRQ domains (Figures 1–4). However, compared with the baseline average CRQ, quality-of-life domains improved after the 8-week intervention and continued to improve at 16 weeks in both groups, using the MCID of 0.5 for CRQ scores.17 The largest improvements were in the CRQ-dyspnea domain, which were clinically and statistically different, with absolute improvements at 16 weeks of 1.85 (P = .02) and 2.21 (P = .003) in groups A and B, respectively. Overall, at 16 weeks, 80% of group A and 71% of group B patients had clinically significant improvements of CRQ-dyspnea domain, with no change or worsening among 20.0% and 28.6%, respectively. CRQ-fatigue also improved in both groups, but the absolute improvement at 16 weeks was greater in group A (1.44) (P = .01) than in group B (0.54) (P = .8). Overall, at 16 weeks, 70.0% of group A and 42.9% of group B patients had clinically significant improvements of CRQ-fatigue domain, with no change or worsening among 30.0% and 57.1%, respectively. While group A patients had clinically significant improvements in CRQ-emotion (0.54) (P = .5) and CRQ-mastery (1.14) (p = 0.1) at 16 weeks, group B patients had the smallest improvements in CRQ-emotion (0.35) (P = .6) and CRQ-mastery (0.28) (P = .8), which were not clinically or statistically significant.
Geriatric Depression Scale Scores
At baseline, average GDS scores were higher among group A patients (mean = 5.6, SD = 3.0) than among group B patients (mean = 4.5, SD = 2.7). Scores consistent with mild-moderate depression were found among 53.8% of patients in group A and 18.2% of patients in group B at baseline, with no scores greater than 10 suggesting severe depression. Over the 16-week period, mean depression scores lowered in both groups (group A: mean = 2.6, SD = 1.9; group B: mean = 2.6, SD = 2.4).
Two-Minute Walk Test
The mean 2-minute walking distance at baseline was less for group A patients (mean = 56.0, SD = 23.3) than for group B patients (mean = 69.3, SD = 34.0). However, the proportion of patients completing the test at 16 weeks varied between the groups, with 46% in group A and 70% in group B. While both groups demonstrated MCID at 16 weeks (8.7–11.7 m), the increase in walking distance was greater in group A patients (39.2 m) than in group B patients (15.1 m), but neither difference was statistically significant.
The results of this pilot study demonstrate the feasibility, potential outcomes, and potential limitations for designing future trials of rehabilitation of homebound patients with COPD. Overall, these preliminary results suggest that 8 weeks of rehabilitation that includes self-management education and either aerobic or strengthening activities at home improves dyspnea and other domains of quality of life, and walking capacity. There may also be a “carryover” effect of the exercise beyond the completion of the program, as seen in the 16-week results in this study. The participants of this study fit several characteristics outlined in the American Thoracic Society position paper on home care guidelines for need of services, including being older, living alone, having several comorbidities, limited functional capabilities, inability to attend outpatient therapy but showing the need for supervised rehabilitation and education, unstable or fragile medical status, and need of frequent monitoring of cardiopulmonary status.1 Moreover, all of the patients fit the Medicare definition of being homebound.1
While the benefits of pulmonary rehabilitation have been established,3,7,11 most available investigations have not included homebound patients, which limit the generalizability of results.12 A recent meta-analysis of 31 randomized trials (n = 667 rehabilitation, 609 control) of pulmonary rehabilitation defined as “exercise training for at least 4 weeks with or without education and/or psychological support” summarized many factors found in program studies.11 Of these 31 trials, the rehabilitation programs varied widely in duration (range, 4–52 weeks, median = 10 weeks) and were conducted in different settings including 4 inpatient (1 combined with home-based) (n = 66 rehabilitation, 67 control), 16 outpatient (1 combined with home-based) (n = 380 rehabilitation, 357 control), 10 home-based (n = 206 rehabilitation, 177 control), and 1 community program (15 rehabilitation, 8 control). Of the 10 studies of home-based interventions, only one study26 targeted homebound patients (n = 46) who were randomized to a 12-week exercise intervention or control group. They found clinically and statistically significant improvements in 6-minute walk (39 m) but did not find clinically significant improvement in quality of life.26 Overall, for all of the studies combined, the quality-of-life domains, including dyspnea, and 6-minute walk demonstrated statistically and clinically significant improvements with rehabilitation. The magnitude of improvements in quality of life and functional exercise capacity is at least as great as available pharmacologic interventions.11 However, because results of the various rehabilitation programs were combined in the meta-analysis, it is not possible to determine the relative benefits of different program settings.
Subjective improvements in exercise and benefits of the program were identified in therapist's clinical notes in both groups, although not examined statistically. These included noting improvement (decrease) in resting heart rate over the 8-week period in both groups, patients able to go through exercise with fewer complaints or rest periods needed, an increased interest in exercise/activity in general, and easier time getting up and down from chair or moving around the house. Some therapists reported favorable lifestyle changing events occurring following the therapy interventions. One of the patients in group B became non-homebound by the end of her therapy and joined a gym to continue her strength work. In some cases, pacing of the strength training exercises seemed to be more easily tolerated by patients than the aerobic training. Some patients in the assisted living environments opted to start attending facility exercise classes.
The results of this pilot study need to be interpreted in light of a number of limitations including gender differences, patient dropout, limited data on functional capacity, short duration of follow-up, lack of health care utilization data, and small sample size. There was a difference in percentage of women between groups that may have influenced outcome measures in the CRQ. Also, while a high proportion of patients did not complete the 8-week intervention (42%), similar rates of dropout have been reported with other pulmonary rehabilitation programs.27 Despite the similarity of dropout in other pulmonary rehabilitation programs, the problem of dropout needs to be addressed in future investigations. In addition to program dropout, 29% of patients did not complete data collection at 16 weeks. Moreover, results on functional outcome with the 2MWT need to be interpreted with caution because of inconsistent performance of the test at follow-up, which may bias the results. Therefore, other more feasible home-based measures of functional performance are needed for future studies. Tests of functional leg strength, such as the step test or 5 times sit to stand, and balance screens such as Tinetti Performance-Oriented Mobility Assessment28 could assess useful functional improvements in future studies. Baseline and post manual muscle tests may have provided a more accurate picture of musculoskeletal changes that occurred with training during our pilot. The benefits of pulmonary rehabilitation decline over time and thus longer duration (eg, 6–12 months) of follow-up is needed to determine the duration of benefit.29,30 In addition, longer duration of follow-up is needed to monitor health care utilization and cost-effectiveness of the program.1,6 Finally, while clinical and statistically significant improvements were found for dyspnea, the small sample size limited statistical power for detecting differences in other outcomes. These results will be helpful for designing larger studies in the future.
The results of this preliminary study suggest that home-based pulmonary rehabilitation is feasible and may be effective for improving disease-specific quality of life and physical functioning in homebound patients with COPD. Further study is needed to define interventions, which produce optimal increases in functional strength and endurance.
The authors thank the staff of Paradigm Rehab and Nursing who provided care for study participants.
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aerobic training; dyspnea; functional strength; homebound; self-management© 2012 Academy of Geriatric Physical Therapy, APTA