Context
The care of patients with chronic obstructive pulmonary disease (COPD) has changed radically over the past 2 decades, and novel therapies can not only improve the health status of patients with COPD but also modify its natural course.
Objective
To systematically review the impact of long-acting bronchodilators, inhaled corticosteroids, nocturnal noninvasive mechanical ventilation, pulmonary rehabilitation, domiciliary oxygen therapy, and disease management programs on clinical outcomes in patients with COPD.
Data Sources
MEDLINE and Cochrane databases were searched to identify all randomized controlled trials and systematic reviews from 1980 to May 2002 evaluating interventions in patients with COPD. We also hand searched bibliographies of relevant articles and contacted experts in the field.
Study Selection and Data Extraction
We included randomized controlled trials that had follow-up of at least 3 months and contained data on at least 1 of these clinical outcomes: health-related quality of life, exacerbations associated with COPD, or death. For pulmonary rehabilitation, we included studies that had a follow-up of at least 6 weeks. Using standard meta-analytic techniques, the effects of interventions were compared with placebo or with usual care. In secondary analyses, the effects of interventions were compared against each other, where possible.
Data Synthesis
Long-acting β2-agonists and anticholinergics (tiotropium) reduced exacerbation rates by approximately 20% to 25% (relative risk [RR] for long-acting β2-agonists, 0.79; 95% CI, 0.69-0.90; RR for tiotropium, 0.74; 95% CI, 0.62-0.89) in patients with moderate to severe COPD. Inhaled corticosteroids also reduced exacerbation rates by a similar amount (RR, 0.76; 95% CI, 0.72-0.80). The beneficial effects were most pronounced in trials enrolling patients with FEV1 between 1 L and 2 L. Combining a long-acting β2-agonist with an inhaled corticosteroid resulted in an approximate 30% (RR, 0.70; 95% CI, 0.62-0.78) reduction in exacerbations. Pulmonary rehabilitation improved the health status of patients with moderate to severe disease, but no material effect was observed on long-term survival or hospitalization rates. Domiciliary oxygen therapy improved survival by approximately 40% in patients with PaO2 lower than 60 mm Hg, but not in those without hypoxia at rest. The data on disease management programs were heterogeneous, but overall no effect was observed on survival or risk of hospitalization. Noninvasive mechanical ventilation was not associated with improved outcomes.
Conclusions
A significant body of evidence supports the use of long-acting bronchodilators and inhaled corticosteroids in reducing exacerbations in patients with moderate to severe COPD. Domiciliary oxygen therapy is the only intervention that has been demonstrated to prolong survival, but only in patients with resting hypoxia.
Chronic obstructive pulmonary disease (COPD) affects more than 5% of the adult population,1 and it is the only major cause of death in the United States in which morbidity and mortality are increasing.2 Although COPD is currently the 4th-leading cause of mortality and the 12th-leading cause of disability, by the year 2020 it is estimated that COPD will be the 3rd-leading cause of death and the 5th-leading cause of disability worldwide.3,4 In 1993, the total economic costs of COPD were estimated to be $24 billion in the United States alone; more than 60% of these costs were direct expenditures related to hospital-based care.4 While these figures are alarming, they most certainly underestimate the true health burdens of COPD because airflow obstruction is an important contributor to other common causes of morbidity and mortality, including ischemic heart disease, stroke, pneumonia, and lung cancer.5-8Quiz Ref IDChronic obstructive pulmonary disease is characterized by irreversible airflow obstruction, secondary to airway inflammation and emphysematous changes in the lung parenchyma.9 Airway hyperresponsiveness also is a common feature of COPD, affecting 60% to 80% of patients with COPD.10 In more than 80% of cases, cigarette smoking is causally linked to the development of COPD.9 Other risk factors include exposure to noxious gases, ambient pollution, and chronic respiratory infections.11,12 A diagnosis of COPD should, therefore, be considered in current or former smokers (or in never smokers with other risk factors) who present with cough, sputum production, or dyspnea, with spirometric evidence of irreversible airflow obstruction.9 The latter sign is defined as a postbronchodilator forced expiratory volume in 1 second (FEV1) value of less than 80% of predicted, in association with an FEV1to forced vital capacity ratio (FEV1/FVC) of less than 70%.9 Smoking cessation is the single most important therapy for improving health outcomes in patients with COPD. Unfortunately, even in the best programs, less than one third of smokers become "sustained" quitters.13,14 Furthermore, once individuals develop demonstrable airflow obstruction, their symptoms (cough and/or dyspnea) may persist even after smoking cessation.9
Over the past 20 years, several novel therapies, such as inhaled corticosteroids, long-acting β2-agonists, and anticholinergics, have been introduced for patients with COPD, with the aim of favorably altering lung function and improving patient symptoms. However, most of the studies that have evaluated these therapies have been short and powered to evaluate the impact on physiological end points, such as FEV1 values. Relatively few studies have evaluated the long-term effects of these interventions on clinical end points, such as health-related quality of life, COPD exacerbations, hospitalizations, or mortality. Because the rate of descent in FEV1 is an imperfect surrogate for these clinical end points,15 we conducted a systematic review of the literature to evaluate the effects of commonly used anti-COPD therapies on patient-centered outcomes, such as health-related quality of life, exacerbations associated with COPD, hospitalizations, and/or mortality.
We decided a priori to examine the published evidence for the following anti-COPD therapies: long-acting β2-agonists, long-acting inhaled anticholinergics (tiotropium), combination therapy with short-acting β2-agonists and short-acting anticholinergics, inhaled corticosteroids, combination therapy with inhaled corticosteroids and long-acting β2-agonists, pulmonary rehabilitation, long-term administration of nocturnal noninvasive mechanical ventilation (NIMV), domiciliary oxygen therapy, and disease management programs (which include any combination of patient education, enhanced follow-up, and/or self-management sessions).16
For each of these therapies, we conducted a literature search using MEDLINE. We limited our search to English-language articles published from January 1, 1980, to May 1, 2002, reporting studies of adults (>19 years of age) in randomized clinical trials. To identify only studies in COPD, we used the following terms: obstructive or chronic obstructive or bronchitis or pulmonary emphysema or airway obstruction or emphysema or mediastinal emphysema or subcutaneous emphysema or COPD or lung diseases, obstructive* or pulmonary diseases, obstructive. Detailed search terms for each of the therapies and search results are available on the author's Web site (Table 1e at http://www.mrl.ubc.ca/sin). To supplement this search, we examined the Cochrane Database of Systematic Reviews of Effectiveness as well as bibliographies of published articles and contacted experts in the field. Although we wanted to include only those studies with follow-up times of at least 6 months, we found insufficient numbers of such studies for most of the interventions, so a follow-up time of 3 months was used as the threshold for inclusion (with the exception of pulmonary rehabilitation programs, for which 6 weeks was used as the threshold). Given the controversy over the value of scoring systems for the quality of randomized controlled trials,17 we did not use a scoring system to adjudicate the quality of the trials included in this review, but we did restrict our analysis to trials that were randomized, placebo-controlled, had blinded ascertainment of end points, had complete or near complete follow-up data, and had baseline characteristics that were well balanced between treatment and control groups. Quiz Ref IDWe discarded studies reporting only physiological variables, such as changes in FEV1, because the correlation between spirometric changes and long-term clinical outcomes in COPD has been shown to be weak.15 Crossover trials were included in this review. We restricted analysis of health-related quality of life to 2 well-standardized and validated instruments in COPD: St George's Respiratory Questionnaire (SGRQ)18 and Chronic Respiratory Questionnaire (CRQ).19 These instruments quantify the extent of physical and psychological impairments related to COPD and allow investigators to determine the (beneficial) effects of specific interventions on the functional status of patients with COPD.18
Where possible, for each end point we combined the results from individual studies to produce summary effect estimates (risk ratios). Heterogeneity of results across individual studies was checked using the Cochran Q test. If significant heterogeneity was observed (P<.05), we used the Dersimonian and Laird random-effects model to combine the results; otherwise, a fixed-effects model was used. As part of a sensitivity analysis for the latter situation, we used a random-effects model to determine the robustness of the data. In all cases, the results obtained from the random-effects model and fixed-effects model were similar. Continuous variables were merged using weighted mean difference technique. The use of the standardized mean difference technique produced similar results. All analyses were conducted using Review Manager version 4.1 (Revman; The Cochrane Collaboration, Oxford, England). For completeness, we also present a general overview of other anti-COPD therapies, such as smoking cessation, oral theophyllines, surgical procedures, and vaccine therapies.
Smoking Cessation and Pneumococcal Vaccination
Smoking cessation is the only therapy proven to slow the accelerated decline in lung function related to COPD.14 While the rate of FEV1 decline is approximately 60 mL per year in smokers, it is only approximately 30 mL per year among ex-smokers.14 Moreover, smoking cessation reduces all-cause mortality rates by approximately 27% (95% confidence interval [CI], 1%-47%), driven largely by very significant reductions in cardiovascular mortality (relative risk [RR] compared with continued smokers, 0.54; 95% CI, 0.32-0.92).20 However, smoking cessation is difficult to achieve and even more difficult to sustain over the long term.21 A single physician recommendation for smoking abstinence is associated with an approximate 5% long-term abstinence rate.22 If abstinence is followed by cessation counseling, education, and nicotine replacement therapy (or treatment with antidepressants such as bupropion and nortriptyline), the long-term abstinence rates can be as high as 25% in patients with early COPD.23,24 Thus, physicians should make every attempt to convince their patients to stop smoking. A detailed evaluation of various smoking cessation methods and programs is beyond the scope of this article, but they are available elsewhere.25-28 Although smoking cessation improves the natural history of COPD, once COPD becomes clinically apparent many sustained quitters remain symptomatic and their airways are persistently inflamed.29 Thus, in symptomatic patients with COPD, additional therapies are indicated.9
Although little evidence is available for the usefulness of influenza and pneumococcal vaccinations for patients with COPD per se, they have been demonstrated in the general elderly population to reduce all-cause, pneumonia, and cardiac hospitalizations30,31 and deaths31 by 30% to 40% with only minor excess risks to recipients.30 Since most patients with COPD are elderly and also are at increased risk of hospitalizations and mortality from various cardiovascular conditions and pneumonia,32 influenza and pneumococcal vaccination also should be instituted for most patients with COPD.
Pharmacological Therapies
Bronchodilators. Airflow obstruction is present in all patients with COPD.9 Accordingly, bronchodilators are used almost universally to provide symptomatic relief for patients with COPD.9 Traditionally, inhaled short-acting β2-agonists and short-acting anticholinergics most commonly were used either on an as-needed basis for rescue care or on a regular basis to prevent or to reduce symptoms.33 Although these medications produce only a modest improvement in lung function in patients with COPD, studies have demonstrated that they reduce symptoms and improve exercise tolerance.34-36 However, no evidence shows that these medications have any effect on the rate of decline in lung function14 or survival.37
Because β2-agonists and anticholinergics produce bronchodilation through different pathways, combination products were introduced in the hopes of achieving greater bronchodilation (and, in turn, better symptom control) than with monotherapy. In 3 trials (1399 patients with advanced COPD, mean FEV1 approximately 1 L in all 3 studies) with follow-up of 3 months or longer, combination therapy with a short-acting β2-agonist and an anticholinergic resulted in 32% (95% CI, 9%-49%) fewer COPD exacerbations compared with monotherapy with a short-acting β2-agonist.38-41 However, combination therapy was not superior to monotherapy with ipratropium (Table 1). Mortality rates over the 3-month follow-up were low and similar among patients treated with combination therapy, short-acting β2-agonist, or ipratropium monotherapy. We did not identify any published studies wherein combination therapy was compared directly with a placebo.
Long-acting β2-agonists were introduced several years ago to achieve longer and more predictable improvements in lung function than what was possible with short-acting β2-agonists.42 Nine placebo-controlled clinical trials (4198 patients with moderate to severe COPD and followed up for ≥3 months) demonstrated a 21% reduction (95% CI, 10%-31%) in COPD exacerbation rates (Figure 1).43-51Quiz Ref IDThey also improved health-related quality of life of patients with COPD (SGRQ, 2.8-unit improvement; 95% CI, 1.6-4.1 vs placebo; CRQ, 4.3-unit improvement; 95% CI, 1.6-7.0). The RR for all-cause mortality compared with placebo was 0.76 (95% CI, 0.39-1.48). The effect on FEV1 was variable. In the 2 trials that evaluated FEV1 changes over at least 1 year, long-acting β2-agonists nonsignificantly increased trough FEV1, on average, by 82 mL (95% CI, −26 to 190 mL per year) compared with placebo.52,53
Five clinical trials of tiotropium (3574 patients with moderate to severe COPD) uniformly have demonstrated a beneficial effect in reducing exacerbation rates compared with either placebo (RR, 0.74; 95% CI, 0.62-0.89) or with ipratropium bromide (RR, 0.78; 95% CI, 0.63-0.95) (Figure 2).55-59 Tiotropium also improved health-related quality of life relative to placebo (SGRQ, 2.9-unit improvement; 95% CI, 1.5-4.3). However, no convincing data to date have shown that they are superior (or inferior) to long-acting β2-agonists in reducing exacerbation rates or improving health status in patients with moderate to severe COPD (RR for exacerbations vs long-acting β2-agonists, 0.93; 95% CI, 0.80-1.08). Moreover, the current trials are too short and underpowered to evaluate the effects of these drugs on all-cause mortality. Long-acting anticholinergics have a powerful effect on FEV1. In the 2 trials that had 1-year follow-up, the trough FEV1 increased by 121 mL (95% CI, 102-141 mL per year) compared with placebo or ipratropium monotherapy.55,59 In the 2 trials that compared long-acting anticholinergics with long-acting β2-agonists over 6 months, long-acting anticholinergics had a more favorable effect on trough FEV1 (37 mL; 95% CI, 12-61 mL).56,57
Inhaled Corticosteroids With and Without Long-Acting β2-Agonists. The use of inhaled corticosteroids remains one of the most contentious issues in COPD pharmacotherapy.60,61 In 6 placebo-controlled trials (1741 patients) with at least a 6-month follow-up period, inhaled corticosteroids led to a 24% reduction in COPD exacerbations (95% CI, 20%-28%) (Table 2).62-69 Importantly, this beneficial effect was modified by disease severity, as measured by FEV1 (Figure 3).62-66,68Quiz Ref IDWhereas the study that had the highest mean FEV1 value failed to demonstrate a beneficial effect of inhaled corticosteroids,68 trials that had a mean FEV1 of less than 2.0 L (or <70% of predicted) almost uniformly demonstrated a positive effect of inhaled corticosteroids on exacerbations, regardless of the duration of the study or the specific formulation used.The pooled RR for COPD exacerbation among trials enrolling patients with a mean FEV1 of 2.0 L or less was 0.75 (95% CI, 0.71-0.80) compared with an RR of 0.96 (95% CI, 0.77-1.20) in a trial with an FEV1 greater than 2.0 L. The effect of inhaled corticosteroids on mortality is uncertain. However, a trend was observed toward reduced mortality in patients randomized to inhaled corticosteroid therapy (Table 2). In a sensitivity analysis, we added the inhaled corticosteroid and placebo data from 2 trials that contained 3 treatment groups (inhaled corticosteroids, inhaled corticosteroids/long-acting β2-agonists, and long-acting β2-agonists) to the original steroid analysis.52,54 The results were materially unchanged (RR for exacerbation, 0.76; 95% CI, 0.73-0.80; RR for mortality, 0.75; 95% CI, 0.57-1.00). Inhaled corticosteroids also decelerated the rate of decline in health status (SGRQ, 1.4-unit improvement relative to placebo; 95% CI, 0.6-2.1; Table 2).
The reporting of adverse effects related to corticosteroid use varied across the studies. Six studies reported the incidence of oral thrush, and its risk was increased among users of inhaled corticosteroids (RR, 2.98; 95% CI, 2.09-4.26)53,54,64,65,67,69; 4 studies reported incidence of dysphonia (RR, 2.02; 95% CI, 1.43-2.83)53,64,65,69; 3 studies reported incidence of bruising (RR, 1.62; 95% CI, 1.18-2.22)53,64,67; and 2 studies reported the risk of cataract (RR, 1.05; 95% CI, 0.84-1.31).64,67 Bone mineral density data from the femoral neck and lumbar spine were reported by the Lung Health Study and EUROSCOP.67,70 Over 3 to 4 years of follow-up (N = 972), a net reduction of 1.57% (95% CI, 2.40%-0.74%) and 1.07% (95% CI, 1.86%-0.28%) was reported in the bone mineral density of the femoral neck and lumbar spine, respectively, compared with placebo. No excess risk of fractures was reported within a 3-year follow-up period (RR, 0.70; 95% CI, 0.36-1.37).67,70 The life-time risk of fractures in those patients who continue to use inhaled corticosteroids for longer than 3 to 4 years is unknown.
Inhaled corticosteroids have a modest effect on FEV1. In the first 6 months of therapy, they increased baseline trough FEV1, on average, by 45 mL (95% CI, 22-69 mL) in the 6 largest trials.64-69 However, after the initial 6 months, the rate of FEV1 decline was unaffected by inhaled corticosteroid therapy (5 mL/y; 95% CI, −1 to 11 mL/y relative to placebo) in the 4 trials reporting this outcome over that time frame.64,67-69
Three clinical trials (2951 patients) demonstrated that combination therapy with inhaled corticosteroids plus long-acting β2-agonists is associated with lower exacerbation rates compared with monotherapy with long-acting β2-agonists (RR, 0.80; 95% CI, 0.71-0.90) or with placebo (RR, 0.70; 95% CI, 0.62-0.78).52-54 A trend was observed toward decreased COPD exacerbations compared with inhaled corticosteroid monotherapy, but it did not achieve statistical significance (Table 3).52-54 The beneficial effects of inhaled corticosteroids and long-acting β2-agonists appeared, therefore, to be additive, not synergistic. The effect of this combination on mortality is uncertain (RR vs placebo, 0.52; 95% CI, 0.20-1.34). Combination therapy, however, was effective in improving trough FEV1 compared with placebo (101 mL/y; 95% CI, 76-126 mL/y), long-acting β2-agonists (34 mL/y; 95% CI, 11-57 mL/y), and inhaled corticosteroids (50 mL/y; 95% CI, 26-74 mL/y).
Nonpharmacological Therapies
Respiratory muscle fatigue and dynamic hyperinflation commonly are observed in patients with severe COPD.71-73 Even at rest patients with COPD work harder than patients without COPD because they have to overcome dynamic lung hyperinflation and airflow obstruction, which limit their tidal volume.72,73 Long-term NIMV therapy potentially should unload the inspiratory muscles of respiration and help restore depleted energy stores and partially reverse respiratory muscle fatigue.74 Moreover, nocturnal NIMV may improve central ventilatory drive and responsiveness to chemical and mechanical stimulation by lowering nocturnal PCO2 levels and improving daytime sleepiness, which help the body to reset the ventilatory thresholds to more normal levels.75 Despite these compelling physiological arguments, the long-term use of NIMV cannot be recommended at this time because there is insufficient clinical trial evidence for its efficacy (N = 142; RR for exacerbation/hospitalization vs usual care, 0.87; 95% CI, 0.67-1.12) (Table 4e at http://www.mrl.ubc.ca/sin).76-79
Patients with advanced COPD experience marked dyspnea and exercise intolerance related in part to generalized muscle weakness and dystrophy, cardiac impairments (eg, cor pulmonale), and nutritional deficiencies.80 Pulmonary rehabilitation programs were developed to address some of these adverse physiological changes in patients with COPD.80Quiz Ref IDAlthough the contents of pulmonary rehabilitation vary from center to center, most programs contain 4 major components: exercise training, education, behavioral modification, and outcome assessment.80 The training intensity of the exercise program is heterogeneous. In general, most aerobic training is targeted at 60% to 90% of the predicted maximal heart rate for about 30 minutes.80 Although most programs emphasize endurance training, some centers also incorporate strength and respiratory muscle training. The 19 clinical trials (1447 patients) we identified support the notion that pulmonary rehabilitation improves the health status of patients with moderate to severe COPD (mean FEV1, 1.0 L; mean age, 66 years) and increases their exercise tolerance beyond that achieved by standard care alone, at least during the time patients are engaged in the rehabilitation program (Table 5e at http://www.mrl.ubc.ca/sin; Figure 4).81-98 Although some heterogeneity was observed in the results (likely arising from the variations in the components of pulmonary rehabilitation program across the studies), pulmonary rehabilitation, on average, improved CRQ scores (dyspnea domain) by 4.1 units and SGRQ (total) scores by 4.4 units. Because clinically relevant thresholds for CRQ and SGRQ are considered to be score changes of 0.5 or higher per question for CRQ99 and 4.0 units or higher for SGRQ,100 the overall effect of pulmonary rehabilitation on the health status of patients with COPD was both clinically and statistically significant. These gains were maintained over the ensuing 3 to 18 months of follow-up (2 trials reported long-term CRQ [dyspnea domain] data, 1.11; 95% CI, 0.31-1.9085,86; and 2 trials reported long-term SGRQ data, −5.55; 95% CI, −8.76 to −2.33).81,86 Pulmonary rehabilitationdid not have any significant effect on mortality (RR, 0.90; 95% CI, 0.65-1.24)85,86,88,89,92,93,95,98 or on hospitalization rates (RR, 0.99; 95% CI, 0.56-1.75).86
Supplemental oxygen is effective in prolonging survival of patients with COPD whose resting PaO2 is lower than 60 mm Hg at sea level (2 trials with 290 patients, RR, 0.61; 95% CI, 0.46-0.82) (Table 6e at http://www.mrl.ubc.ca/sin).101,102 However, in trials in which the resting mean PaO2 was 60 mm Hg or higher, no survival advantage was related to oxygen therapy (2 trials with 211 patients, pooled RR, 1.16; 95% CI, 0.85-1.58).103,104 Supplemental oxygen therapy appeared to have a mild beneficial effect on the mean pulmonary arterial pressure and CRQ (dyspnea domain) scores.105-108
Disease management is an approach to coordinate resources across the health care system with the aim of fostering continuity of care and increasing patients' knowledge and control over their chronic disease.109 Because the care of patients with COPD frequently requires multiple caregivers, including physicians (both generalists and specialists), nurses, physiotherapists, pharmacists, and nutritionists, a process to promote integration and seamless care may improve clinical outcomes in COPD. However, the efficacy of disease management programs in COPD remains uncertain (Table 4).110-117 On average, these programs appear to improve health status of patients but may not meaningfully impact hospitalization rates. However, because of marked heterogeneity in the content of the programs and their effects, these data need to be interpreted cautiously and further study is required.
The effects of oral theophyllines on exacerbation and mortality in COPD are uncertain and few well-conducted randomized trials are available powered on these end points.118 However, theophyllines appear to have some beneficial effects on FEV1 as well as on the arterial contents of oxygen and carbon dioxide of patients with moderate to severe COPD.118 Oral theophyllines, however, increase the risk of nausea by approximately 7 fold. Three well-conducted clinical trials (1321 patients) demonstrated that lung volume reduction surgery (LVRS) improves health-related quality of life and exercise tolerance of patients with an FEV1 less than 30% of predicted.119-121 However, even among carefully selected patients, LVRS did not modify all-cause mortality rates over 5 years.119 The short-term mortality was higher among patients who received LVRS than among those who were treated medically.119,121 In those patients with FEV1 less than 20% predicted, LVRS increased the risk of mortality by approximately 4 fold (beyond medical therapy).122 Accordingly, for most patients with COPD, LVRS cannot be recommended at this time. Lung transplantation should be reserved for patients with very advanced COPD (and without major comorbid conditions) and whose projected survival is less than 2 to 3 years.123 Although lung transplantation may improve functional status and exercise tolerance of patients with COPD, no well-conducted studies have been performed to demonstrate survival benefits.124
Chronic obstructive pulmonary disease is common and associated with immense health and economic burdens.9Airflow obstruction is a cardinal feature of COPD, and therapies that produce bronchodilation have been demonstrated to improve patients' health status and reduce exacerbations. Long-acting β2-agonists and tiotropium both reduce exacerbation rates by approximately 25% in patients with moderate to severe COPD. Long-acting β2-agonists induce bronchodilation by relaxing smooth muscle cells through activation of the adenylate cyclase pathways, which in turn increases intracellular concentrations of cyclic adenosine monophosphate.42 In addition, in vitro experiments have suggested that these compounds may have certain anti-inflammatory properties.125 Anticholinergic bronchodilators, on the other hand, induce bronchodilation by attenuating vagal tone in the airways.126 While both ipratropium and tiotropium are nonselective antagonists with similar binding affinity for the muscarinic receptors, tiotropium dissociates more than 100 times more slowly from the receptor complex than ipratropium, making the former more potent and longer acting than the latter.126 In most situations, tiotropium may be used once daily, while ipratropium generally is given 4 to 6 times per day.
The current evidence suggests that these 2 classes of long-acting bronchodilators (long-acting β2-agonists and anticholinergics) have similar efficacy, although only 2 trials (1830 patients) have directly compared them. Whether a combination of these 2 classes of long-acting bronchodilators would have an additive benefit on clinical outcomes (over monotherapy) is unknown. Until such data are published, this practice cannot be routinely recommended.
Inhaled corticosteroids also reduce exacerbation rates by approximately 25%. The mechanisms by which inhaled corticosteroids exert their beneficial effects on COPD outcomes are unclear. However, they attenuate airway hyperresponsiveness,67,127 which may be an important predictor of COPD mortality,128 and reduce some129-132 but not all133,134 components of airway inflammation and oxidative stress. Some caution should be exercised in using inhaled corticosteroids because they are associated with increased risk of certain adverse effects including thrush, oral candidiasis, and bruising. Inhaled corticosteroids also have some deleterious effect on bone mineral density, but the effect was very modest and was not associated with an excess risk of clinically evident fractures during these admittedly short-term trials. While the trials may have been too short to detect any changes, it is possible that inhaled corticosteroids may not increase fracture rates as, by reducing the frequency of COPD exacerbations by one quarter, they will spare patients from exposure to higher doses of systemic corticosteroids.
Theoretically, adding long-acting β2-agonists to inhaled corticosteroid use may amplify the anti-inflammatory effects of corticosteroids135 since long-acting β2-agonists may enhance nuclear localization of glucocorticoid receptors in inflammatory cells,136 making it easier for corticosteroids to effectively block cytokine expression in these cells. Long-acting β2-agonists also may increase the effectiveness of corticosteroids in suppressing expression of adhesion molecules such as intracellular adhesion molecule 1.137 Consistent with these observations, clinical studies suggest that by combining long-acting β2-agonists and inhaled corticosteroids, exacerbation rates are lowered beyond that achieved by individual component therapy. However, the beneficial effects are additive (not synergistic) (RR, 0.70 vs placebo).
Supplemental oxygen therapy improves dyspnea scores, reduces pulmonary arterial pressure, and prolongs survival in those patients with COPD with a PaO2 lower than 60 mm Hg. Pulmonary rehabilitation is effective in improving exercise tolerance and health status of patients with an FEV1 less than 1.5 L. The relative improvements in patients' health status are maintained during the 18 months of follow-up in some studies, but its effects beyond that time frame are uncertain. No compelling evidence is available showing that pulmonary rehabilitation reduces frequency of hospitalizations or death in patients with COPD.
Although conceptually appealing, disease management programs have not yet been shown to improve clinical outcomes in patients with COPD (Table 4). However, this finding may reflect differences in the core components of disease management strategies across various studies. In general, studies that taught self-management skills and provided comprehensive educational services to patients had better outcomes than those that provided closer follow-up (Table 4). Well-designed comparative studies are needed to validate these initial observations.
In summary, consistent with the guidelines from the Global Initiative for Chronic Obstructive Lung Disease committee,9 smoking cessation is the cornerstone of chronic COPD management. Inhaled bronchodilator therapy on an as-needed basis should be considered for patients who experience occasional exacerbations. Regular bronchodilator therapy may be instituted for those with persistent symptoms. Combination therapy (with both a β2-agonist and an anticholinergic) or the use of long-acting agents would appear to be the best approaches in this setting. In symptomatic individuals with moderate to severe disease, addition of inhaled corticosteroids with or without long-acting β2-agonists and pulmonary rehabilitation should be considered. In patients with hypoxia at rest, supplemental oxygen therapy should be instituted. Although little evidence is available specifically examining the effects of influenza and pneumococcal vaccinations in the COPD population, they have been demonstrated to reduce hospitalizations and deaths in the general elderly population with only minor excess risks to recipients, and, thus, they are recommended for most patients with symptomatic COPD.
Corresponding Author and Reprints: Don D. Sin, MD, MPH, 2E4.29 Walter C. Mackenzie Center, University of Alberta, Edmonton, Alberta, Canada T6G 2B7 (e-mail: don.sin@ualberta.ca).
Author Contributions:Study concept and design: Sin, McAlister, Man, Anthonisen.
Acquisition of data: Sin.
Analysis and interpretation of data: Sin, McAlister, Man, Anthonisen.
Drafting of the manuscript: Sin.
Critical revision of the manuscript for important intellectual content: Sin, McAlister, Man, Anthonisen.
Statistical expertise: Sin, McAlister, Man, Anthonisen.
Obtained funding: Sin.
Administrative, technical, or material support: Sin, McAlister, Man, Anthonisen.
Funding/Support: Drs Sin and McAlister are supported by a New Investigator Award from the Canadian Institutes of Health Research and a Population Health Investigator Award from the Alberta Heritage Foundation for Medical Research.
1.Coultas
DB, Mapel
D, Gagnon
R, Lydick
E. The health impact of undiagnosed airflow obstruction in a national sample of United States adults.
Am J Respir Crit Care Med. 2001;164:372-377.
PubMed.
Google ScholarCrossref 2.Murray
CJ, Lopez
AD. Alternative projections of mortality and disability by cause 1990-2020: Global Burden of Disease Study.
Lancet. 1997;349:1498-1504.
PubMed.
Google ScholarCrossref 5.Tockman
MS, Anthonisen
NR, Wright
EC, Donithan
MG. Airways obstruction and the risk for lung cancer.
Ann Intern Med. 1987;106:512-518.
PubMed.
Google ScholarCrossref 6.Engstrom
G, Wollmer
P, Hedblad
B, Juul-Moller
S, Valind
S, Janzon
L. Occurrence and prognostic significance of ventricular arrhythmia is related to pulmonary function: a study from "men born in 1914," Malmo, Sweden.
Circulation. 2001;103:3086-3091.
PubMed.
Google ScholarCrossref 7.Malcolm
C, Marrie
TJ. Antibiotic therapy for ambulatory patients with community-acquired pneumonia in an emergency department setting.
Arch Intern Med. 2003;163:797-802.
PubMed.
Google ScholarCrossref 8.Sin
DD, Man
SF. Why are patients with chronic obstructive pulmonary disease at increased risk of cardiovascular diseases? the potential role of systemic inflammation in chronic obstructive pulmonary disease.
Circulation. 2003;107:1514-1519.
PubMed.
Google ScholarCrossref 9.Pauwels
RA, Buist
AS, Calverley
PM, Jenkins
CR, Hurd
SS, GOLD Scientific Committee. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: NHLBI/WHO Global Initiative for Chronic Obstructive Lung Disease (GOLD) workshop summary.
Am J Respir Crit Care Med. 2001;163:1256-1276.
PubMed.
Google ScholarCrossref 10.Tashkin
DP, Altose
MD, Bleeker
ER, Connett
JE, Kanner
RE, Lee
WW, Wise
R. The Lung Health Study: airway responsiveness to inhaled methacholine in smokers with mild to moderate airflow limitation: the Lung Health Study Research Group.
Am Rev Respir Dis. 1992;145:301-310.
PubMedGoogle ScholarCrossref 13.Kanner
RE, Connett
JE, Altose
MD,
et al. Gender difference in airway hyperresponsiveness in smokers with mild COPD: the Lung Health Study.
Am J Respir Crit Care Med. 1994;150:956-961.
PubMedGoogle ScholarCrossref 14.Anthonisen
NR, Connett
JE, Kiley
JP,
et al. Effects of smoking intervention and the use of an inhaled anticholinergic bronchodilator on the rate of decline of FEV1: the Lung Health Study.
JAMA. 1994;272:1497-1505.
PubMedGoogle ScholarCrossref 15.Spencer
S, Calverley
PM, Sherwood Burge
P, Jones
PW, ISOLDE Study Group. Inhaled steroids in obstructive lung disease: Health status deterioration in patients with chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2001;163:122-128.
PubMedGoogle ScholarCrossref 16.Weingarten
SR, Henning
JM, Badamgarav
E,
et al. Interventions used in disease management programmes for patients with chronic illness—which ones work? meta-analysis of published reports.
BMJ. 2002;325:925.
PubMedGoogle ScholarCrossref 17.Auerbach
AD, Goldman
L. Beta-blockers and reduction of cardiac events in noncardiac surgery: clinical applications.
JAMA. 2002;287:1445-1447.
PubMedGoogle Scholar 19.Guyatt
GH, Berman
LB, Townsend
M, Pugsley
SO, Chambers
LW. A measure of quality of life for clinical trials in chronic lung disease.
Thorax. 1987;42:773-778.
PubMedGoogle ScholarCrossref 20.Multiple Risk Factor Intervention Trial Research Group. Multiple Risk Factor Intervention Trial: risk factor changes and mortality results.
JAMA. 1982;248:1465-1477.
PubMedGoogle ScholarCrossref 21.Ebrahim
S, Smith
GD. Systematic review of randomised controlled trials of multiple risk factor interventions for preventing coronary heart disease.
BMJ. 1997;314:1666-1674.
PubMedGoogle ScholarCrossref 22.Lindholm
LH, Ekbom
T, Dash
C, Eriksson
M, Tibblin
G, Schersten
B. The impact of health care advice given in primary care on cardiovascular risk.
BMJ. 1995;310:1105-1109.
PubMedGoogle ScholarCrossref 23.Murray
RP, Connett
JE, Rand
CS, Pan
W, Anthonisen
NR. Persistence of the effect of the Lung Health Study (LHS) smoking intervention over eleven years.
Prev Med. 2002;35:314-319.
PubMedGoogle ScholarCrossref 24.Hughes
JR, Stead
LF, Lancaster
T. Antidepressants for smoking cessation.
Cochrane Database Syst Rev. 2003;2:CD000031.
PubMedGoogle Scholar 25.Fiore
MC. Treating Tobacco Use and Dependence: A Public Health Service Clinical Practice Guideline. Press Briefing: Center for Tobacco Research and Intervention, University of Wisconsin Medical School, June27 , 2000. US Public Health Service. Available at:
http://www.surgeongeneral.gov/tobacco/mf062700.htm. Accessibility verified October 2, 2003.
26.Ketola
E, Sipila
R, Makela
M. Effectiveness of individual lifestyle interventions in reducing cardiovascular disease and risk factors.
Ann Med. 2000;32:239-251.
PubMedGoogle ScholarCrossref 27.Lancaster
T, Stead
LF. Self-help interventions for smoking cessation.
Cochrane Database Syst Rev. 2002;3:CD001118.
PubMedGoogle Scholar 28.Silagy
C, Lancaster
T, Stead
L, Mant
D, Fowler
G. Nicotine replacement therapy for smoking cessation.
Cochrane Database Syst Rev. 2002;4:CD000146.
PubMedGoogle Scholar 29.Domagala-Kulawik
J, Maskey-Warzechowska
M, Kraszewska
I, Chazan
R. The cellular composition and macrophage phenotype in induced sputum in smokers and ex-smokers with COPD.
Chest. 2003;123:1054-1059.
PubMedGoogle ScholarCrossref 30.Govaert
TM, Thijs
CT, Masurel
N, Sprenger
MJ, Dinant
GJ, Knottnerus
JA. The efficacy of influenza vaccination in elderly individuals: a randomized double-blind placebo-controlled trial.
JAMA. 1994;272:1661-1665.
PubMedGoogle ScholarCrossref 31.Nichol
KL, Nordin
J, Mullooly
J, Lask
R, Fillbrandt
K, Iwane
M. Influenza vaccination and reduction in hospitalizations for cardiac disease and stroke among the elderly.
N Engl J Med. 2003;348:1322-1332.
PubMedGoogle ScholarCrossref 32.Vilkman
S, Keistinen
T, Tuuponen
T, Kivela
SL. Survival and cause of death among elderly chronic obstructive pulmonary disease patients after first admission to hospital.
Respiration. 1997;64:281-284.
PubMedGoogle ScholarCrossref 34.Jenkins
SC, Heaton
RW, Fulton
TJ, Moxham
J. Comparison of domiciliary nebulized salbutamol and salbutamol from a metered-dose inhaler in stable chronic airflow limitation.
Chest. 1987;91:804-807.
PubMedGoogle ScholarCrossref 35.Ikeda
A, Nishimura
K, Koyama
H, Tsukino
M, Mishima
M, Izumi
T. Dose response study of ipratropium bromide aerosol on maximum exercise performance in stable patients with chronic obstructive pulmonary disease.
Thorax. 1996;51:48-53.
PubMedGoogle ScholarCrossref 36.Guyatt
GH, Townsend
M, Pugsley
SO,
et al. Bronchodilators in chronic air-flow limitation: effects on airway function, exercise capacity, and quality of life.
Am Rev Respir Dis. 1987;135:1069-1074.
PubMedGoogle Scholar 37.Anthonisen
NR, Connett
JE, Enright
PL, Manfreda
J, Lung Health Study Research Group. Hospitalizations and mortality in the Lung Health Study.
Am J Respir Crit Care Med. 2002;166:333-339.
PubMedGoogle ScholarCrossref 38.Dorinsky
PM, Reisner
C, Ferguson
GT, Menjoge
SS, Serby
CW, Witek
TJ
Jr. The combination of ipratropium and albuterol optimizes pulmonary function reversibility testing in patients with COPD.
Chest. 1999;115:966-971.
PubMedGoogle ScholarCrossref 39.COMBIVENT Inhalation Aerosol Study Group. In chronic obstructive pulmonary disease, a combination of ipratropium and albuterol is more effective than either agent alone: an 85-day multicenter trial.
Chest. 1994;105:1411-1419.
PubMedGoogle ScholarCrossref 40.COMBIVENT Inhalation Solution Study Group. Routine nebulized ipratropium and albuterol together are better than either alone in COPD.
Chest. 1997;112:1514-1521.
PubMedGoogle ScholarCrossref 41.Tashkin
DP, Ashutosh
K, Bleecker
ER,
et al. Comparison of the anticholinergic bronchodilator ipratropium bromide with metaproterenol in chronic obstructive pulmonary disease: a 90-day multi-center study.
Am J Med. 1986;81:81-90.
PubMedGoogle ScholarCrossref 43.Wadbo
M, Lofdahl
CG, Larsson
K,
et al. Effects of formoterol and ipratropium bromide in COPD: a 3-month placebo-controlledstudy.
Eur Respir J. 2002;20:1138-1146.
PubMedGoogle ScholarCrossref 44.van Noord
JA, de Munck
DR, Bantje
TA, Hop
WC, Akveld
ML, Bommer
AM. Long-term treatment of chronic obstructive pulmonary disease with salmeterol and the additive effect of ipratropium.
Eur Respir J. 2000;15:878-885.
PubMedGoogle ScholarCrossref 45.Chapman
KR, Arvidsson
P, Chuchalin
AG,
et al. The addition of salmeterol 50 microg bid to anticholinergic treatment in patients with COPD: a randomized, placebo controlled trial: chronic obstructive pulmonary disease.
Can Respir J. 2002;9:178-185.
PubMedGoogle ScholarCrossref 46.Jones
PW, Bosh
TK. Quality of life changes in COPD patients treated with salmeterol.
Am J Respir Crit Care Med. 1997;155:1283-1289.
PubMedGoogle ScholarCrossref 47.Rossi
A, Kristufek
P, Levine
BE,
et al. Comparison of the efficacy, tolerability, and safety of formoterol dry powder and oral, slow-release theophylline in the treatment of COPD.
Chest. 2002;121:1058-1069.
PubMedGoogle ScholarCrossref 48.Dahl
R, Greefhorst
LA, Nowak
D,
et al. Inhaled formoterol dry powder versus ipratropium bromide in chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2001;164:778-784.
PubMedGoogle ScholarCrossref 49.Aalbers
R, Ayres
J, Backer
V,
et al. Formoterol in patients with chronic obstructive pulmonary disease: a randomized, controlled, 3-month trial.
Eur Respir J. 2002;19:936-943.
PubMedGoogle ScholarCrossref 50.Rennard
SI, Anderson
W, ZuWallack
R,
et al. Use of a long-acting inhaled beta2-adrenergic agonist, salmeterol xinafoate, in patients with chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2001;163:1087-1092.
PubMedGoogle ScholarCrossref 51.Mahler
DA, Donohue
JF, Barbee
RA,
et al. Efficacy of salmeterol xinafoate in the treatment of COPD.
Chest. 1999;115:957-965.
PubMedGoogle ScholarCrossref 52.Szafranski
W, Cukier
A, Ramirez
A,
et al. Efficacy and safety of budesonide/formoterol in the management of chronic obstructive pulmonary disease.
Eur Respir J. 2003;21:74-81.
PubMedGoogle ScholarCrossref 53.Calverley
P, Pauwels
R, Vestbo
J,
et al. Combined salmeterol and fluticasone in the treatment of chronic obstructive pulmonary disease: a randomised controlled trial.
Lancet. 2003;361:449-456.
PubMedGoogle ScholarCrossref 54.Mahler
DA, Wire
P, Horstman
D,
et al. Effectiveness of fluticasone propionate and salmeterol combination delivered via the Diskus device in the treatment of chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2002;166:1084-1091.
PubMedGoogle ScholarCrossref 55.Casaburi
R, Mahler
DA, Jones
PW,
et al. A long-term evaluation of once-daily inhaled tiotropium in chronic obstructive pulmonary disease.
Eur Respir J. 2002;19:217-224.
PubMedGoogle ScholarCrossref 56.Donohue
JF, van Noord
JA, Bateman
ED,
et al. A 6-month, placebo-controlled study comparing lung function and health status changes in COPD patients treated with tiotropium or salmeterol.
Chest. 2002;122:47-55.
PubMedGoogle ScholarCrossref 57.Brusasco
V, Hodder
R, Miravitlles
M, Korducki
L, Towse
L, Kesten
S. Health outcomes following treatment for six months with once daily tiotropium compared with twice daily salmeterol in patients with COPD.
Thorax. 2003;58:399-404.
PubMedGoogle ScholarCrossref 58.van Noord
JA, Bantje
TA, Eland
ME, Korducki
L, Cornelissen
PJ. A randomised controlled comparison of tiotropium and ipratropium in the treatment of chronic obstructive pulmonary disease: the Dutch Tiotropium Study Group.
Thorax. 2000;55:289-294.
PubMedGoogle ScholarCrossref 59.Vincken
W, van Noord
JA, Greefhorst
AP,
et al. Improved health outcomes in patients with COPD during 1 yr's treatment with tiotropium.
Eur Respir J. 2002;19:209-216.
PubMedGoogle ScholarCrossref 60.Calverley
PM. Inhaled corticosteroids are beneficial in chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2000;161:341-342; discussion 344.
PubMedGoogle ScholarCrossref 61.Barnes
PJ. Inhaled corticosteroids are not beneficial in chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2000;161:342-344; discussion 344.
PubMedGoogle ScholarCrossref 62.Bourbeau
J, Rouleau
MY, Boucher
S. Randomised controlled trial of inhaled corticosteroids in patients with chronic obstructive pulmonary disease.
Thorax. 1998;53:477-482.
PubMedGoogle ScholarCrossref 63.Weir
DC, Bale
GA, Bright
P, Sherwood Burge
P. A double-blind placebo-controlled study of the effect of inhaled beclomethasone dipropionate for 2 years in patients with nonasthmatic chronic obstructive pulmonary disease.
Clin Exp Allergy. 1999;29(suppl 2):125-128.
PubMedGoogle ScholarCrossref 64.Burge
PS, Calverley
PM, Jones
PW, Spencer
S, Anderson
JA, Maslen
TK. Randomised, double blind, placebo controlled study of fluticasone propionate in patients with moderate to severe chronic obstructive pulmonary disease: the ISOLDE trial.
BMJ. 2000;320:1297-1303.
PubMedGoogle ScholarCrossref 65.Paggiaro
PL, Dahle
R, Bakran
I, Frith
L, Hollingworth
K, Efthimiou
J. Multicentre randomised placebo-controlled trial of inhaled fluticasone propionate in patients with chronic obstructive pulmonary disease: International COPD Study Group.
Lancet. 1998;351:773-780.
PubMedGoogle ScholarCrossref 66.van der Valk
P, Monninkhof
E, van der Palen
J, Zielhuis
G, van Herwaarden
C. Effect of discontinuation of inhaled corticosteroids in patients with chronic obstructive pulmonary disease: the COPE study.
Am J Respir Crit Care Med. 2002;166:1358-1363.
PubMedGoogle ScholarCrossref 67.Lung Health Study Research Group. Effect of inhaled triamcinolone on the decline in pulmonary function in chronic obstructive pulmonary disease.
N Engl J Med. 2000;343:1902-1909.
PubMedGoogle ScholarCrossref 68.Vestbo
J, Sorensen
T, Lange
P, Brix
A, Torre
P, Viskum
K. Long-term effect of inhaled budesonide in mild and moderate chronic obstructive pulmonary disease: a randomised controlled trial.
Lancet. 1999;353:1819-1823.
PubMedGoogle ScholarCrossref 69.Pauwels
RA, Lofdahl
CG, Laitinen
LA,
et al. Long-term treatment with inhaled budesonide in persons with mild chronic obstructive pulmonary disease who continue smoking: European Respiratory Society Study on Chronic Obstructive Pulmonary Disease.
N Engl J Med. 1999;340:1948-1953.
PubMedGoogle ScholarCrossref 70.Johnell
O, Pauwels
R, Lofdahl
CG,
et al. Bone mineral density in patients with chronic obstructive pulmonary disease treated with budesonide Turbuhaler.
Eur Respir J. 2002;19:1058-1063.
PubMedGoogle ScholarCrossref 71.Ninane
V, Rypens
F, Yernault
JC, DeTroyer
A. Abdominal muscle use during breathing in patients with chronic airflow obstruction.
Am Rev Respir Dis. 1992;146:16-21.
PubMedGoogle ScholarCrossref 72.Scano
G, Gorini
M, Duranti
R, Misuri
G, Iandelli
I, Gigliotti
F. Physiological changes during severe airflow obstruction in chronic obstructive pulmonary disease.
Monaldi Arch Chest Dis. 1999;54:413-416.
PubMedGoogle Scholar 73.Ninane
V, Yernault
JC, de Troyer
A. Intrinsic PEEP in patients with chronic obstructive pulmonary disease: role of expiratory muscles.
Am Rev Respir Dis. 1993;148:1037-1042.
PubMedGoogle ScholarCrossref 74.Celli
BR, Rassulo
J, Corral
R. Ventilatory muscle dysfunction in patients with bilateral idiopathic diaphragmatic paralysis: reversal by intermittent external negative pressure ventilation.
Am Rev Respir Dis. 1987;136:1276-1278.
PubMedGoogle ScholarCrossref 75.Meyer
TJ, Hill
NS. Noninvasive positive pressure ventilation to treat respiratory failure.
Ann Intern Med. 1994;120:760-770.
Google ScholarCrossref 76.Garrod
R, Mikelsons
C, Paul
EA, Wedzicha
JA. Randomized controlled trial of domiciliary noninvasive positive pressure ventilation and physical training in severe chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 2000;162:1335-1341.
PubMedGoogle ScholarCrossref 77.Casanova
C, Celli
BR, Tost
L,
et al. Long-term controlled trial of nocturnal nasal positive pressure ventilation in patients with severe COPD.
Chest. 2000;118:1582-1590.
PubMedGoogle ScholarCrossref 78.Clini
E, Sturani
C, Rossi
A,
et al. The Italian multicentre study on noninvasive ventilation in chronic obstructive pulmonary disease patients.
Eur Respir J. 2002;20:529-538.
PubMedGoogle ScholarCrossref 79.Meecham Jones
DJ, Paul
EA, Jones
PW, Wedzicha
JA. Nasal pressure support ventilation plus oxygen compared with oxygen therapy alone in hypercapnic COPD.
Am J Respir Crit Care Med. 1995;152:538-544.
PubMedGoogle ScholarCrossref 81.Finnerty
JP, Keeping
I, Bullough
I, Jones
J. The effectiveness of outpatient pulmonary rehabilitation in chronic lung disease: a randomized controlled trial.
Chest. 2001;119:1705-1710.
PubMedGoogle ScholarCrossref 82.Hernandez
MT, Rubio
TM, Ruiz
FO, Riera
HS, Gil
RS, Gomez
JC. Results of a home-based training program for patients with COPD.
Chest. 2000;118:106-114.
PubMedGoogle ScholarCrossref 83.Stulbarg
MS, Carrieri-Kohlman
V, Demir-Deviren
S,
et al. Exercise training improves outcomes of a dyspnea self-management program.
J Cardiopulm Rehabil. 2002;22:109-121.
PubMedGoogle ScholarCrossref 84.Behnke
M, Taube
C, Kirsten
D, Lehnigk
B, Jorres
RA, Magnussen
H. Home-based exercise is capable of preserving hospital-based improvements in severe chronic obstructive pulmonary disease.
Respir Med. 2000;94:1184-1191.
PubMedGoogle ScholarCrossref 85.Guell
R, Casan
P, Belda
J,
et al. Long-term effects of outpatient rehabilitation of COPD: a randomized trial.
Chest. 2000;117:976-983.
PubMedGoogle ScholarCrossref 86.Griffiths
TL, Burr
ML, Campbell
IA,
et al. Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: a randomised controlled trial.
Lancet. 2000;355:362-368.
PubMedGoogle ScholarCrossref 87.Ringbaek
TJ, Broendum
E, Hemmingsen
L,
et al. Rehabilitation of patients with chronic obstructive pulmonary disease: exercise twice a week is not sufficient!
Respir Med. 2000;94:150-154.
PubMedGoogle ScholarCrossref 88.Ries
AL, Kaplan
RM, Myers
R, Prewitt
LM. Maintenance after pulmonary rehabilitation in chronic lung disease: a randomized trial.
Am J Respir Crit Care Med. 2003;167:880-888.
PubMedGoogle ScholarCrossref 89.Engstrom
CP, Persson
LO, Larsson
S, Sullivan
M. Long-term effects of a pulmonary rehabilitation programme in outpatients with chronic obstructive pulmonary disease: a randomized controlled study.
Scand J Rehabil Med. 1999;31:207-213.
PubMedGoogle ScholarCrossref 90.Larson
JL, Covey
MK, Wirtz
SE,
et al. Cycle ergometer and inspiratory muscle training in chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 1999;160:500-507.
PubMedGoogle ScholarCrossref 91.Wedzicha
JA, Bestall
JC, Garrod
R, Garnham
R, Paul
EA, Jones
PW. Randomized controlled trial of pulmonary rehabilitation in severe chronic obstructive pulmonary disease patients, stratified with the MRC dyspnoea scale.
Eur Respir J. 1998;12:363-369.
PubMedGoogle ScholarCrossref 92.Bendstrup
KE, Ingemann Jensen
J, Holm
S, Bengtsson
B. Out-patient rehabilitation improves activities of daily living, quality of life and exercise tolerance in chronic obstructive pulmonary disease.
Eur Respir J. 1997;10:2801-2806.
PubMedGoogle ScholarCrossref 93.Ries
AL, Kaplan
RM, Limberg
TM, Prewitt
LM. Effects of pulmonary rehabilitation on physiologic and psychosocial outcomes in patients with chronic obstructive pulmonary disease.
Ann Intern Med. 1995;122:823-832.
PubMedGoogle ScholarCrossref 94.Goldstein
RS, Gort
EH, Stubbing
D, Avendano
MA, Guyatt
GH. Randomised controlled trial of respiratory rehabilitation.
Lancet. 1994;344:1394-1397.
PubMedGoogle ScholarCrossref 95.Wijkstra
PJ, Van Altena
R, Kraan
J, Otten
V, Postma
DS, Koeter
GH. Quality of life in patients with chronic obstructive pulmonary disease improves after rehabilitation at home.
Eur Respir J. 1994;7:269-273.
PubMedGoogle ScholarCrossref 96.Lake
FR, Henderson
K, Briffa
T, Openshaw
J, Musk
AW. Upper-limb and lower-limb exercise training in patients with chronic airflow obstruction.
Chest. 1990;97:1077-1082.
PubMedGoogle ScholarCrossref 97.Simpson
K, Killian
K, McCartney
N, Stubbing
DG, Jones
NL. Randomised controlled trial of weightlifting exercise in patients with chronic airflow limitation.
Thorax. 1992;47:70-75.
PubMedGoogle ScholarCrossref 98.Troosters
T, Gosselink
R, Decramer
M. Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: a randomized trial.
Am J Med. 2000;109:207-212.
PubMedGoogle ScholarCrossref 99.Jaeschke
R, Singer
J, Guyatt
GH. Measurement of health status: ascertaining the minimal clinically important difference.
Control Clin Trials. 1989;10:407-415.
PubMedGoogle ScholarCrossref 100.Jones
PW. Interpreting thresholds for a clinically significant change in health status in asthma and COPD.
Eur Respir J. 2002;19:398-404.
PubMedGoogle ScholarCrossref 101.Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial.
Ann Intern Med. 1980;93:391-398.
PubMedGoogle ScholarCrossref 102.Medical Research Council Working Party. Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema.
Lancet. 1981;1:681-686.
PubMedGoogle Scholar 103.Gorecka
D, Gorzelak
K, Sliwinski
P, Tobiasz
M, Zielinski
J. Effect of long-term oxygen therapy on survival in patients with chronic obstructive pulmonary disease with moderate hypoxaemia.
Thorax. 1997;52:674-679.
PubMedGoogle ScholarCrossref 104.Chaouat
A, Weitzenblum
E, Kessler
R,
et al. A randomized trial of nocturnal oxygen therapy in chronic obstructive pulmonary disease patients.
Eur Respir J. 1999;14:1002-1008.
PubMedGoogle ScholarCrossref 105.Eaton
T, Garrett
JE, Young
P,
et al. Ambulatory oxygen improves quality of life of COPD patients: a randomised controlled study.
Eur Respir J. 2002;20:306-312.
PubMedGoogle ScholarCrossref 106.McDonald
CF, Blyth
CM, Lazarus
MD, Marschner
I, Barter
CE. Exertional oxygen of limited benefit in patients with chronic obstructive pulmonary disease and mild hypoxemia.
Am J Respir Crit Care Med. 1995;152:1616-1619.
PubMedGoogle ScholarCrossref 107.Fletcher
EC, Luckett
RA, Goodnight-White
S, Miller
CC, Qian
W, Costarangos-Galarza
C. A double-blind trial of nocturnal supplemental oxygen for sleep desaturation in patients with chronic obstructive pulmonary disease and a daytime PaO2 above 60 mm Hg.
Am Rev Respir Dis. 1992;145:1070-1076.
PubMedGoogle ScholarCrossref 108.Timms
RM, Khaja
FU, Williams
GW. Hemodynamic response to oxygen therapy in chronic obstructive pulmonary disease.
Ann Intern Med. 1985;102:29-36.
PubMedGoogle ScholarCrossref 110.Bourbeau
J, Julien
M, Maltais
F,
et al. Reduction of hospital utilization in patients with chronic obstructive pulmonary disease: a disease-specific self-management intervention.
Arch Intern Med. 2003;163:585-591.
PubMedGoogle ScholarCrossref 111.Hermiz
O, Comino
E, Marks
G, Daffurn
K, Wilson
S, Harris
M. Randomised controlled trial of home based care of patients with chronic obstructive pulmonary disease.
BMJ. 2002;325:938.
PubMedGoogle ScholarCrossref 112.Weinberger
M, Murray
MD, Marrero
DG,
et al. Effectiveness of pharmacist care for patients with reactive airways disease: a randomized controlled trial.
JAMA. 2002;288:1594-1602.
PubMedGoogle ScholarCrossref 113.Watson
PB, Town
GI, Holbrook
N, Dwan
C, Toop
LJ, Drennan
CJ. Evaluation of a self-management plan for chronic obstructive pulmonary disease.
Eur Respir J. 1997;10:1267-1271.
PubMedGoogle ScholarCrossref 114.Gallefoss
F, Bakke
PS. Impact of patient education and self-management on morbidity in asthmatics and patients with chronic obstructive pulmonary disease.
Respir Med. 2000;94:279-287.
PubMedGoogle ScholarCrossref 115.Littlejohns
P, Baveystock
CM, Parnell
H, Jones
PW. Randomised controlled trial of the effectiveness of a respiratory health worker in reducing impairment, disability, and handicap due to chronic airflow limitation.
Thorax. 1991;46:559-564.
PubMedGoogle ScholarCrossref 116.Cockcroft
A, Bagnall
P, Heslop
A,
et al. Controlled trial of respiratory health worker visiting patients with chronic respiratory disability.
Br Med J (Clin Res Ed). 1987;294:225-228.
PubMedGoogle ScholarCrossref 117.Weinberger
M, Oddone
EZ, Henderson
WG. Does increased access to primary care reduce hospital readmissions? Veterans Affairs Cooperative Study Group on Primary Care and Hospital Readmission.
N Engl J Med. 1996;334:1441-1447.
PubMedGoogle ScholarCrossref 118.Ram
FS, Jones
PW, Castro
AA,
et al. Oral theophylline for chronic obstructive pulmonary disease.
Cochrane Database Syst Rev. 2002;4:CD003902.
PubMedGoogle Scholar 119.Fishman
A, Martinez
F, Naunheim
K,
et al. A randomized trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema.
N Engl J Med. 2003;348:2059-2073.
PubMedGoogle ScholarCrossref 120.Geddes
D, Davies
M, Koyama
H,
et al. Effect of lung-volume-reduction surgery in patients with severe emphysema.
N Engl J Med. 2000;343:239-245.
PubMedGoogle ScholarCrossref 121.Goldstein
RS, Todd
TR, Guyatt
G,
et al. Influence of lung volume reduction surgery (LVRS) on health related quality of life in patients with chronic obstructive pulmonary disease.
Thorax. 2003;58:405-410.
PubMedGoogle ScholarCrossref 122.National Emphysema Treatment Trial Research Group. Patients at high risk of death after lung-volume-reduction surgery.
N Engl J Med. 2001;345:1075-1083.
PubMedGoogle ScholarCrossref 124.Hosenpud
JD, Bennett
LE, Keck
BM, Edwards
EB, Novick
RJ. Effect of diagnosis on survival benefit of lung transplantation forend-stage lung disease.
Lancet. 1998;351:24-27.
PubMedGoogle ScholarCrossref 127.Verhoeven
GT, Hegmans
JP, Mulder
PG, Bogaard
JM, Hoogsteden
HC, Prins
JB. Effects of fluticasone propionate in COPD patients with bronchial hyperresponsiveness.
Thorax. 2002;57:694-700.
PubMedGoogle ScholarCrossref 128.Hospers
JJ, Postma
DS, Rijcken
B, Weiss
ST, Schouten
JP. Histamine airway hyper-responsiveness and mortality from chronic obstructive pulmonary disease: a cohort study.
Lancet. 2000;356:1313-1317.
PubMedGoogle ScholarCrossref 129.Hattotuwa
KL, Gizycki
MJ, Ansari
TW,
et al. The effects of inhaled fluticasone on airway inflammation in chronic obstructive pulmonary disease: a double-blind, placebo-controlled biopsy study.
Am J Respir Crit Care Med. 2002;165:1592-1596.
PubMedGoogle ScholarCrossref 130.Confalonieri
M, Mainardi
E, Della Porta
R,
et al. Inhaled corticosteroids reduce neutrophilic bronchial inflammation in patients with chronic obstructive pulmonary disease.
Thorax. 1998;53:583-585.
PubMedGoogle ScholarCrossref 131.Sugiura
H, Ichinose
M, Yamagata
S, Koarai
A, Shirato
K, Hattori
T. Correlation between change in pulmonary function and suppression of reactive nitrogen species production following steroid treatment in COPD.
Thorax. 2003;58:299-305.
PubMedGoogle ScholarCrossref 132.Yildiz
F, Kaur
AC, Ilgazli
A,
et al. Inhaled corticosteroids may reduce neutrophilic inflammation in patients with stable chronic obstructive pulmonary disease.
Respiration. 2000;67:71-76.
PubMedGoogle ScholarCrossref 133.Culpitt
SV, Maziak
W, Loukidis
S,
et al. Effect of high dose inhaled steroid on cells, cytokines, and proteases in induced sputum in chronic obstructive pulmonary disease.
Am J Respir Crit Care Med. 1999;160:1635-1639.
PubMedGoogle ScholarCrossref 134.Cox
G, Whitehead
L, Dolovich
M,
et al. A randomized controlled trial on the effect of inhaled corticosteroids on airways inflammation in adult cigarette smokers.
Chest. 1999;115:1271-1277.
PubMedGoogle ScholarCrossref 135.Barnes
PJ. Scientific rationale for inhaled combination therapy with long-acting beta2-agonists and corticosteroids.
Eur Respir J. 2002;19:182-191.
PubMedGoogle ScholarCrossref 136.Baluk
P, McDonald
DM. The beta 2-adrenergic receptor agonist formoterol reduces microvascular leakage by inhibiting endothelial gap formation.
Am J Physiol. 1994;266:L461-L468.
PubMedGoogle Scholar 137.Silvestri
M, Fregonese
L, Sabatini
F, Dasic
G, Rossi
GA. Fluticasone and salmeterol downregulate in vitro, fibroblast proliferation and ICAM-1 or H-CAM expression.
Eur Respir J. 2001;18:139-145.
PubMedGoogle ScholarCrossref 138.Waterhouse
JC, Fishwick
D, Burge
PS, Calverley
PMA, Anderson
JA, on behalf of the ISOLDE Trial group. What caused death in the ISOLDE study?
Eur Respir J. 1999;14(suppl 30):387S.
Google Scholar