Repeating pulmonary rehabilitation: prevalence, predictors and outcomes.

BACKGROUND AND OBJECTIVE: Pulmonary rehabilitation (PR) is a cornerstone of care in chronic respiratory diseases; yet its benefits diminish over time. Repeating PR may be beneficial; however, little is known about the characteristics and outcomes of repeaters. This study aimed to establish the proportion of repeaters, identify characteristics that predict repetition and compare the magnitude of benefits achieved between initial and subsequent programmes. METHODS: Patients with stable chronic respiratory diseases who attended PR over a 9-year period were included. Outcome measures included the 6-min walk distance (6MWD) and the Chronic Respiratory Disease Questionnaire-Self-Reported (CRDQ-SR). Independent predictors of repeating were identified. RESULTS: Of 296 patients, 59 (20%) repeated PR, most within 1-3 years. Following the initial programme, repeaters had significant decline in 6MWD (-96.1 ± 84.6 m; P < 0.001) and CRDQ-SR scores (mean decline -3.6 points, range -0.1 to -7.9 points; P < 0.005). The improvement in 6MWD was less in the repeat programme compared with the first (38.4 ± 50.7 m vs 67 ± 40.4 m; P = 0.005), while the change in CRDQ-SR was similar in all domains. A chronic obstructive pulmonary disease diagnosis increased the odds of repeating PR (odds ratio (OR) 4.8; P = 0.005) while improved mastery in the initial programme reduced the odds (OR 0.9; P = 0.033). CONCLUSIONS: One in five patients repeated PR, achieving clinically significant improvements in exercise tolerance and quality of life. Patients with small improvements in disease mastery after initial PR were more likely to repeat the programme and may benefit from earlier intervention or longer duration PR.

Physiotherapy interventions on chest wall mobility in obstructive lung diseases: A systematic review.

PURPOSE: The aim of this systematic review was to investigate the effectiveness of physiotherapy interventions on chest mobility in obstructive lung diseases. METHODS: Searches were performed in PEDro, Pubmed and Cochrane Central Register of Controlled Trials databases without language restrictions between 2010 and 25th December 2020. Randomized controlled trials (RCTs) investigating physiotherapy interventions on chest wall mobility were included. Two independent reviewers screened studies, extracted data, and assessed methodological quality of included studies. The assessment of risk of bias was conducted using the PEDro scale for RCTs. The articles were excluded if they have less than 5 out of 10 score. RESULTS: Five studies included had good to excellent quality. A total of 139 patients were included in all RCTs. Intervention duration ranged from a single session to 12 weeks and the intervention schedules varied, consisting of 1-24 sessions, lasting 5-45 min per sessions. Three studies used respiratory muscle stretching and releasing techniques, one study combined respiratory muscle stretching with aerobic training, and one study planned diaphragmatic breathing. Four studies assessed chest wall mobility with optoelectronic plethysmography, whereas one study used measuring tape. CONCLUSIONS: The result of this first systematic review that investigates the effects of physiotherapy interventions on chest wall mobility in obstructive lung diseases suggests that more and better quality RCTs with objective measurement tools are required.

Home care by outreach nursing for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow obstruction, worsening exercise performance and health deterioration. It is associated with significant morbidity, mortality and health system burden. OBJECTIVES: To evaluate the effectiveness of outreach respiratory health care worker programmes for COPD patients in terms of improving lung function, exercise tolerance and health related quality of life (HRQL) of patient and carer, and reducing mortality and medical service utilisation. SEARCH METHODS: The Cochrane Airways Group Specialised Register of Trials was searched (November 2011). Study references were hand-searched for additional studies we contacted study authors to identify other unpublished studies. SELECTION CRITERIA: We included only randomised controlled trials of COPD patients. We included interventions involving an outreach nurse visiting patients in their homes, providing support, education, monitoring health and liaising with physicians. Studies in which the therapeutic intervention under test was physical training were not included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information. MAIN RESULTS: We pooled mortality data from eight studies and found a non-significant reduction in mortality at 12 months (OR 0.72, 95% CI 0.45 to, 1.15).We pooled four studies that assessed disease-specific heath-related quality of life (HRQL) and found a statistically significant improvement in HRQL (mean difference -2.61, 95% CI -4.82 to -0.40).Hospitalisations were reported in five studies. Although there was no statistically significant difference in the number of hospitalisations (OR 1.01, 95% CI 0.71 to 1.44), there was significant heterogeneity. Although this heterogeneity appeared to be caused by one outlying study with a statistically significant decrease in hospitalisations in patients receiving home care, whereas the other studies showed a non-significant increase in hospitalisations, we could not draw firm conclusions about why this heterogeneity exists. Data on GP visits and emergency department presentations were available, however no consistent effect in these was observed with the intervention. The intervention also incurred higher health care costs than standard care as reported in a single study.Very few studies provided data on lung function or exercise performance, so there was insufficient evidence to assess impact on these outcomes. AUTHORS' CONCLUSIONS: Outreach nursing programmes for COPD improved disease-specific HRQL. However the effect on hospitalisations was heterogeneous, reducing admissions in one study, but increasing them in others, therefore we could not draw firm conclusions for this outcome.

Home care by outreach nursing for chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow obstruction, worsening exercise performance and health deterioration. It is associated with significant morbidity, mortality and health system burden. OBJECTIVES: To evaluate the effectiveness of outreach respiratory health care worker programmes for COPD patients in terms of improving lung function, exercise tolerance and health related quality of life (HRQL) of patient and carer, and reducing mortality and medical service utilisation. SEARCH STRATEGY: The Cochrane Airways Group Specialised Register of Trials was searched (November 2009). Study references were hand-searched for additional studies we contacted study authors to identify other unpublished studies. SELECTION CRITERIA: We included only randomised controlled trials of COPD patients. We included interventions involving an outreach nurse visiting patients in their homes, providing support, education, monitoring health and liaising with physicians. Studies in which the therapeutic intervention under test was physical training were not included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information. MAIN RESULTS: We included five new studies in this update, resulting in a total of nine included studies.We pooled mortality data from eight studies and found a non-significant reduction in mortality at 12 months (OR 0.72, 95% CI 0.45 to, 1.15).We pooled four studies that assessed disease-specific heath-related quality of life (HRQL) and found a statistically significant improvement in HRQL (mean difference -2.61, 95% CI -4.82 to -0.40).Hospitalisations were reported in five studies. Although there was no statistically significant difference in the number of hospitalisations (OR 1.01, 95% CI 0.71 to 1.44), there was significant heterogeneity. Although this heterogeneity appeared to be caused by one outlying study with a statistically significant decrease in hospitalisations in patients receiving home care, whereas the other studies showed a non-significant increase in hospitalisations, we could not draw firm conclusions about why this heterogeneity exists. Data on GP visits and emergency department presentations were available, however no consistent effect in these was observed with the intervention. The intervention also incurred higher health care costs than standard care as reported in a single study.Very few studies provided data on lung function or exercise performance, so there was insufficient evidence to assess impact on these outcomes. AUTHORS' CONCLUSIONS: Outreach nursing programmes for COPD improved disease-specific HRQL. However the effect on hospitalisations was heterogeneous, reducing admissions in one study, but increasing them in others, therefore we could not draw firm conclusions for this outcome.

Alexithymia in respiratory rehabilitation.

PURPOSE: To date, there are no studies that have investigated the role of alexithymia in respiratory rehabilitation. We aimed to observe the prevalence of alexithymia in patients attending respiratory rehabilitation and to verify the presence of a difference between alexithymics and non-alexithymics responsiveness to the respiratory rehabilitation standard protocol. METHODS: A prospective cohort study evaluating the influence of alexithymia on functional recovery of in-patients afferent to the Respiratory Rehabilitation Unit of IRCCS San Raffaele Pisana. Sixty patients were consecutively enrolled into the study and evaluated for alexithymia, anxiety and depression. Functional recovery was assessed with the six-minute walking test (6MWT). Prior and post-completion of this test dyspnoea, oxygen saturation and cardiac frequency were recorded. RESULTS: Alexithymia was not found to be significantly affecting the functional recovery of participants in respiratory rehabilitation. The distance walked at the 6MWT (6MWD) increased in both alexithymics and non-alexithymics (p(alexithymics) = 0.014; p(non-alexithymics) < 0.0001). Dyspnoea strongly improved among non-alexithymics, although a signal for improvement was also found in alexithymics (p(alexithymics) = 0.046; p(non-alexithymics) = 0.0001). CONCLUSIONS: These findings suggest that alexithymia did not have a significant impact on functional recovery of patients in respiratory rehabilitation.

[High altitude and preexisting lung diseases]. / Affections pulmonaires et attitude.

Today, a growing number of people, some of them suffering from lung diseases, travel to high altitude resorts. It is sometimes not easy for the general practitioner to adequately counsel these patients. Based on our knowledge of physiopathology and clinical studies, the present paper addresses the effects of high altitude in patients with preexisting lung diseases and provides recommendations in order to optimize the sojourn at high altitude.

Forced expiratory technique, directed cough, and autogenic drainage.

In health, secretions produced in the respiratory tract are cleared by mucociliary transport, cephalad airflow bias, and cough. In disease, increased secretion viscosity and volume, dyskinesia of the cilia, and ineffective cough combine to reduce secretion clearance, leading to increased risk of infection. In obstructive lung disease these conditions are further complicated by early collapse of airways, due to airway compression, which traps both gas and secretions. Techniques have been developed to optimize expiratory flow and promote airway clearance. Directed cough, forced expiratory technique, active cycle of breathing, and autogenic drainage are all more effective than placebo and comparable in therapeutic effects to postural drainage; they require no special equipment or care-provider assistance for routine use. Researchers have suggested that standard chest physical therapy with active cycle of breathing and forced expiratory technique is more effective than chest physical therapy alone. Evidence-based reviews have suggested that, though successful adoption of techniques such as autogenic drainage may require greater control and training, patients with long-term secretion management problems should be taught as many of these techniques as they can master for adoption in their therapeutic routines.

High-frequency assisted airway clearance.

High-frequency airway clearance assist devices generate either positive or negative transrespiratory pressure excursions to produce high-frequency, small-volume oscillations in the airways. Intrapulmonary percussive ventilation creates a positive transrespiratory pressure by injecting short, rapid inspiratory flow pulses into the airway opening and relies on chest wall elastic recoil for passive exhalation. High-frequency chest wall compression generates a negative transrespiratory pressure by compressing the chest externally to cause short, rapid expiratory flow pulses, and relies on chest wall elastic recoil to return the lungs to functional residual capacity. High-frequency chest wall oscillation uses a chest cuirass to generate biphasic changes in transrespiratory pressure. In any case (positive or negative pressure pulses or both), the general idea is get air behind secretions and move them toward the larger airways, where they can be coughed up and expectorated. These techniques have become ubiquitous enough to constitute a standard of care. Yet, despite over 20 years of research, clinical evidence of efficacy for them is still lacking. Indeed, there is insufficient evidence to support the use of any single airway clearance technique, let alone judge any one of them superior. Aside from patient preference and capability, cost-effectiveness studies based on existing clinical data are necessary to determine when a given technique is most practical.

Risk, protective factors, and supportive interventions in chronic airway obstruction.

Fifty-nine patients with chronic airway obstruction completed the Schedule of Recent Experiences and Social Assets Scale (SAS) to measure life stress and social supports. Patients with highest stress and lowest SAS scores (the high-risk group) were randomly assigned to a pulmonary rehabilitation group, self-help support group, or waiting-list control group. Patients with lower stress and/or higher SAS scores (the low-risk group) served as controls. Six months later, a records review showed that high-risk control patients were hospitalized more often than low-risk control patients and for more days than high-risk patients in rehabilitation and self-help support groups. Discriminant analysis determined that SAS and life stress scores predicted subsequent hospitalization, but age, sex, previous hospitalizations, and severity of illness did not. Measurements of stress and social supports can help identify high-risk patients. In turn, professionals might assist these patients by increasing their supports.

Validation of the Clinical COPD questionnaire in Italian language.

BACKGROUND: The development and validation study of the Clinical Chronic Obstructive Disease (COPD) Questionnaire (CCQ) has recently been published in this journal. The CCQ is the first questionnaire that incorporates both clinician and patient guideline goals in the clinical control evaluation of patients with COPD in general clinical practice. The aim of this study is the validation of the CCQ questionnaire in Italian, in specific pulmonary disease clinical practice. METHODS: Validity was tested on a population of healthy subjects and patients with COPD, using the Italian validated version of the Short Form Health Survey (SF-36) and guideline recommended routine measurement in COPD patients (FEV1, FVC, BMI and functional dyspnoea). Test-retest reliability was tested by re-administering the CCQ after 2 weeks. Responsiveness was tested by re-administering the CCQ after three weeks of hospital pulmonary rehabilitation. Distance walked and Borg breathlessness rating were measured at the end of the six-minute walking test (6 MWT), before and after rehabilitation. RESULTS: Cross-sectional data were collected from 175 subjects (55 healthy; 40 mild-moderate, 50 severe and 25 very severe COPD). Cronbach's alpha was high (0.89). The CCQ scores in patients were significantly worse than in healthy subjects. The CCQ total score in patients with COPD was significantly worse in those with BMI < or = 21. Significant correlations were found between the CCQ total score and domains of the SF-36 (rho = -0.43 to rho = -0.72). The correlation between the CCQ and FEV1 % predicted was rho = -0.57. The correlation between the CCQ and MRC was rho = 0.63. Test-retest reliability was determined in 112 subjects over a period of two weeks (Intra Class Coefficient = 0.99). Forty-six patients with COPD showed significant improvement in CCQ scores, distance-walked and Borg breathlessness rating after 3 weeks of pulmonary rehabilitation, indicating CCQ responsiveness. CONCLUSIONS: The CCQ is self-administered and has been specially developed to measure clinical control in patients with COPD. Data support its validity, reliability and responsiveness in Italian and in specific pulmonary disease clinical practice.

Outpatient oxygen therapy in chronic obstructive pulmonary disease. A review of 13 years' experience and an evaluation of modes of therapy.

Thirteen years' experience with home oxygen for patients with advanced chronic obstructive pulmonary disease are reviewed. Home oxygen is safe and relieves pulmonary hypertension and elevated RBC mass in some, but not all patients. Marked clinical improvement is the most important result of long-term home oxygen use, including reduced hospitalizations and return to gainful employment for a few patients. Chronic compensated carbon dioxide retention is well tolerated and adaptive in cases of severe chronic airflow obstruction. New oxygen concentrators are effective in correcting hypoxemia and may make home oxygen administration more convenient and less expensive.

Results of a comprehensive rehabilitation program. Physiologic and functional effects on patients with chronic obstructive pulmonary disease.

Forty-two patients with chronic obstructive pulmonary disease participated in a comprehensive inpatient rehabilitation program. Criteria for a safe, maximum treadmill exercise regimen were established; all patients pursued this regimen for six weeks, without complications, even though 31 of 39 patients showed a decline in PaO2 with exercise. Postprogram O2 consumption, minute ventilation, heart rate, and respiratory rate were significantly reduced during exercise when compared with preprogram values. Sixteen of 29 patients improved in terms of dyspnea class; an additional 11 of these 29 improved with regard to activities of daily living. Most patients who improved physiologically also improved functionally. Patients able to tolerate higher levels of treadmill exercise initially had the greatest improvement in postcourse exercise performance. The data suggest that precourse functional and exercise classification is useful in selecting candidates who will receive the greatest functional benefits from participation in rehabilitative programs.

[Guidelines for outpatient pulmonary rehabilitation in Austria]. / Richtlinien für die ambulante pneumologische Rehabilitation in Österreich.

Pulmonary rehabilitation has become a standard of care for patients with chronic lung disease. It has been clearly demonstrated that pulmonary rehabilitation improves exercise capacity and quality of life in patients with chronic lung disease and reduces the number of hospital days and other measures of health-care utilization in patients with chronic obstructive pulmonary disease (COPD). This is an update of the guidelines in outpatient pulmonary rehabilitation in Austria, closely related to the official American Thoracic Society and European Respiratory Society Statement published in 2013.The guidelines represent standards of quality for requirements of structural and personal qualifications.

Impact of activities in self-esteem of patients in a pulmonary rehabilitation program.

OBJECTIVE: To evaluate self-esteem and self-image of respiratory diseases patients in a Pulmonary Rehabilitation Program, who participated in socialization and physical fitness activities, and of patients who participated only in physical fitness sessions. METHODS: A descriptive cross-sectional exploratory study. Out of a total of 60 patients analyzed, all enrolled in the Pulmonary Rehabilitation Program, 42 participated in at least one of the proposed activities, 10 did not participate in any activity and 8 were excluded (7 were discharged and 1 died). RESULTS: When the two groups were compared, despite the fact that both demonstrated low self-esteem and self-image, the difference between them was relevant (p<0.05) regarding self-esteem, indicating that those who participated in the proposed socialization activities had better self-esteem than the individuals who only did the physical fitness sessions. Regarding self-image, the difference between the groups was not relevant (p>0.05). CONCLUSION: The Pulmonary Rehabilitation Program patients evaluated presented low self-esteem and self-image; however, those carrying out some socialization activity proposed had better self-esteem as compared to the individuals who did only the physical fitness sessions.

Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: a randomized trial.

PURPOSE: Pulmonary rehabilitation programs are effective in patients with severe chronic obstructive pulmonary disease (COPD) in the short term, but their long-term effects are not known. We investigated the short- and long-term effects of a 6-month outpatient rehabilitation program in patients with severe COPD. SUBJECTS AND METHODS: One hundred patients were randomly assigned to receive either an exercise training program that included cycling, walking, and strength training (n = 50) or usual medical care (n = 50). Thirty-four patients in the training group were evaluated after 6 months (end of training), and 26 were evaluated after 18 months of follow-up. In the control group, 28 patients were evaluated at 6 months and 23 after 18 months. We measured pulmonary function, 6-minute walking distance, maximal exercise capacity, peripheral and respiratory muscle strength, and quality of life (on a 20 to 140-point scale), and estimated the cost-effectiveness of the program. RESULTS: At 6 months, the training group showed improvement in 6-minute walking distance [mean difference (training - control) of 52 m; 95% confidence interval (CI), 15 to 89 m], maximal work load (12 W; 95% CI, 6 to 19 W), maximal oxygen uptake (0.26 liters/min; 95% CI, 0.07 to 0.45 liters/min), quadriceps force (18 Nm; 95% CI, 7 to 29 Nm), inspiratory muscle force (11 cm H(2)O; 95% CI, 3 to 20 cm H(2)O), and quality of life (14 points; 95% CI, 6 to 21 points; all P <0.05). At 18 months all these differences persisted (P <0.05), except for inspiratory muscle strength. For 6-minute walking distance and quality of life, the differences between the training group and controls at 18 months exceeded the minimal clinically-important difference. CONCLUSION: Among patients who completed the 6-month program, outpatient training resulted in significant and clinically relevant changes in 6-minute walking distance, maximal exercise performance, peripheral and respiratory muscle strength, and quality of life. Most of these effects persisted 18 months after starting the program.

Therapeutic approaches to chronic obstructive pulmonary disease: an emerging consensus.

In response to reports of rising asthma morbidity and mortality, several consensus statements have been drafted to guide the treatment of asthma. More recently, attempts have been made to develop similar guidelines for the management of chronic obstructive pulmonary disease (COPD). Just as the two diseases differ in their pathophysiology, their treatment algorithms have differed. For both disease groups, avoidance of further airway injury is the initial step in treatment. For asthmatics, this is often allergen avoidance, but for patients with COPD the usual inciting factor is cigarette smoking, thereby making smoking cessation the necessary first step. Whereas beta 2-agonist bronchodilators are used as needed in asthma management, regular bronchodilator therapy with anticholinergic drugs is the first-line approach in COPD. The role of anti-inflammatory drugs differs markedly between the two disease groups. Asthmatic patients benefit dramatically from inhaled anti-inflammatory drugs; little or no benefit can be demonstrated for the majority of patients with COPD. In COPD, the role of exercise rehabilitation programs can improve exercise tolerance. For selected patients with COPD with persistent hypoxemia, the use of supplemental oxygen can reduce mortality. For both patient groups, educational interventions can play a valuable role in making patients patients effective partners in their own care.

Exercise limitation and pulmonary rehabilitation in chronic obstructive pulmonary disease.

Impairment of exercise tolerance is a common problem in patients with severe chronic obstructive pulmonary disease. The cause of exercise intolerance in patients with severe chronic obstructive pulmonary disease is multifactorial and includes impaired lung mechanics, fatigue of inspiratory muscles, impaired gas exchange, right ventricular dysfunction, malnutrition, occult cardiac disease, deconditioning, and psychologic problems; however, impaired lung mechanics and gas exchange abnormalities seem to be the major limiting factors. Recently, the approach to management of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease has changed because improvement in exercise tolerance has been demonstrated after pulmonary rehabilitation. Other adjunctive measures that have been shown to contribute to the observed improvement in exercise tolerance include administration of oxygen, nutritional support, cessation of smoking, and psychosocial support. The roles of ventilatory muscle endurance training, respiratory muscle rest therapy, nasally administered continuous positive airway pressure, and training of the muscles of the upper extremities are less clearly defined.

Use of factor analysis to consolidate multiple outcome measures in chronic obstructive pulmonary disease.

Multiple outcome measures are often used in clinical research and practice. However, the use of multiple measures inflates the probability of a type I error. In this paper, we used factor analysis techniques to reduce multiple outcome measures to a lesser number of orthogonal dimensions. The data were obtained from 119 patients with chronic obstructive pulmonary disease. Each patient had measurements made of 28 variables, including multiple parameters of pulmonary function, exercise tolerance and gas exchange. Factor analysis using a maximum likelihood iterative solution was performed. The factors were then rotated to a varimax solution. The analysis yielded four meaningful factors: exercise tolerance, disease severity, lung volumes and flow rates. Exercise tolerance and disease severity were the most important factors accounting, respectively, for 44 and 13% of the common variance. For further analyses, these composite factors could be used or a representative clinical measure from each factor might be chosen. We conclude that many physiologic measures provide highly correlated information about chronic obstructive pulmonary disease patients. Factor analysis may help reduce these measures into a smaller number of reliable composites.

Generic and specific measurement of health-related quality of life in a clinical trial of respiratory rehabilitation.

The purpose of this study was to compare the performance of measures of health-related quality of life in a randomized controlled trial of respiratory rehabilitation versus conventional community care for patients with chronic airflow limitation. The study included 89 stable patients with moderate to severe chronic airflow limitation with measurement of health status at 12, 18, and 24 weeks. Outcomes included two disease-specific (the Oxygen Cost Diagram and the Chronic Respiratory Questionnaire [CRQ]) measures, a generic health profile (the Sickness Impact Profile [SIP]), and two utility measures (the Standard Gamble and the Quality of Well-Being index [QWB]). Of the measures, only the four domains of the CRQ (dyspnea, fatigue, mastery, and emotional function) showed statistically significant differences (P < or = 0.05) between treatment and control groups. Correlation between change in the CRQ and change in other relevant measures, including the 6-minute walk test and global ratings of change in dyspnea, fatigue, and emotional function were generally weak to moderate (from 0.19 to 0.51). All correlations between change in the QWB, SIP, and Standard Gamble and other measures were very weak or weak (up to 0.30). Correlation between change in the three generic measures were all very weak (<0.15). The results suggest that unless investigators include responsive and valid disease-specific measures of health-related quality of life in controlled trials in chronic diseases, they risk misleading conclusions about the effect of treatments on health status.

Assessing the minimal important difference in symptoms: a comparison of two techniques.

We have developed a method for estimating the minimally important difference (MID) for health status measures. Whereas the conventional approach requires patients to judge themselves relative to their memories, our method requires patients to judge themselves relative to others with the same condition. In this study we examined whether our method (based on between-patient differences) and the conventional method (based on within-patient changes) provides comparable estimates of the MID for one health status measure: the Chronic Respiratory Questionnaire. Patients with chronic obstructive pulmonary disease who were participating in a supervised respiratory rehabilitation program were included if they were in stable health (n = 112). Their mean score per question in the Chronic Respiratory Questionnaire was 4.5 (range, 1 to 7; where bigger values indicate better health). Our method estimated that the MID was 0.5 (95% confidence interval 0.4 to 0.7). This estimate was similar to the MID previously found using the conventional method. These observations support the role of the Chronic Respiratory Questionnaire for measuring patient's symptoms, the validity of our approach for assessing the MID, and an estimate on the order of 0.5 as the threshold for this particular health status measure.