Haemodynamic compensations for exercise tissue oxygenation in early stages of COPD: an integrated cardiorespiratory assessment study.

BACKGROUND: Cardiovascular comorbidities are increasingly being recognised in early stages of chronic obstructive pulmonary disease (COPD) yet complete cardiorespiratory functional assessments of individuals with mild COPD or presenting with COPD risk factors are lacking. This paper reports on the effectiveness of the cardiocirculatory-limb muscles oxygen delivery and utilisation axis in smokers exhibiting no, or mild to moderate degrees of airflow obstruction using standardised cardiopulmonary exercise testing (CPET). METHODS: Post-bronchodilator spirometry was used to classify participants as 'ever smokers without' (n=88), with 'mild' (n=63) or 'mild-moderate' COPD (n=56). All underwent CPET with continuous concurrent monitoring of oxygen uptake (V'O2) and of bioimpedance cardiac output (Qc) enabling computation of arteriovenous differences (a-vO2). Mean values of Qc and a-vO2 were mapped across set ranges of V'O2 and Qc isolines to allow for meaningful group comparisons, at same metabolic and circulatory requirements. RESULTS: Peak exercise capacity was significantly reduced in the 'mild-moderate COPD' as compared with the two other groups who showed similar pulmonary function and exercise capacity. Self-reported cardiovascular and skeletal muscle comorbidities were not different between groups, yet disease impact and exercise intolerance scores were three times higher in the 'mild-moderate COPD' compared with the other groups. Mapping of exercise Qc and a-vO2 also showed a leftward shift of values in this group, indicative of a deficit in peripheral O2 extraction even for submaximal exercise demands. Concurrent with lung hyperinflation, a distinctive blunting of exercise stroke volume expansion was also observed in this group. CONCLUSION: Contrary to the traditional view that cardiovascular complications were the hallmark of advanced disease, this study of early COPD spectrum showed a reduced exercise O2 delivery and utilisation in individuals meeting spirometry criteria for stage II COPD. These findings reinforce the preventive clinical management approach to preserve peripheral muscle circulatory and oxidative capacities.

Cost-Effectiveness of an Extended Home Visit Program for Oxygen-Dependent COPD Patients.

BACKGROUND: Long-term oxygen therapy in COPD is usually supervised through home-care respiratory programs. Such programs often involve an intensive education intervention at the initiation of long-term oxygen therapy, followed by an extended follow-up period that aims toward home oxygen adherence. The objective of this study was to estimate the cost-effectiveness ratio of such a maintenance program. METHODS: A simulation model was developed that compared 2 strategies after the intensive education intervention: (1) enrollment and (2) no enrollment in a maintenance program. The study population consisted of a hypothetical cohort of 200 patients (100 patients per group; mean age, 74 years; 45% men; mean FEV1 of 43% predicted value; and mean resting PaO2 while breathing air, 50 mm Hg). Effectiveness assumptions of the program were derived from a current literature review. The primary outcome was the ratio of the incremental cost of the program per quality-adjusted life-years gained. Only direct costs were considered; a health-care system perspective was adopted. Costs are reported in 2020 Canadian dollars (Can $). RESULTS: Over a 5-year period, an extended home-visit program may prevent 9 deaths and provide an additional 39 years of life and 24 quality-adjusted life-years. Compared with usual care (ie, no enrollment in the maintenance program), the incremental cost-effectiveness ratio was Can $17,197 per quality-adjusted life-years gained. Sensitivity analyses demonstrated the robustness of the model. Only a reduction in adherence of 25% per year would increase the incremental cost-effectiveness ratio per quality-adjusted life-years beyond the threshold of Can $50,000 that is usually considered as acceptable from a health-care system perspective. CONCLUSIONS: An extended home-visit program to maintain or improve adherence to long-term oxygen therapy in patients with COPD would most likely be cost-effective.

Economic Evaluation of Umeclidinium/Vilanterol versus Umeclidinium or Salmeterol in Symptomatic Non-Exacerbating Patients with COPD from a UK Perspective Using the GALAXY Model.

INTRODUCTION: Dual bronchodilators are recommended as maintenance treatment for patients with symptomatic COPD in the UK; further evidence is needed to evaluate cost-effectiveness versus monotherapy. Cost-effectiveness of umeclidinium/vilanterol versus umeclidinium and salmeterol from a UK healthcare perspective in patients without exacerbations in the previous year was assessed using post hoc EMAX trial data. METHODS: The validated GALAXY model was populated with baseline characteristics and treatment effects from the non-exacerbating subgroup of the symptomatic EMAX population (COPD assessment test score ≥10) and 2020 UK healthcare and drug costs. Outputs included estimated exacerbation rates, costs, life-years (LYs), and quality-adjusted LYs (QALYs); incremental cost-effectiveness ratio (ICER) was calculated as incremental cost/QALY gained. The base case (probabilistic model) used a 10-year time horizon, assumed no treatment discontinuation, and discounted future costs and QALYs by 3.5% annually. Sensitivity and scenario analyses assessed robustness of model results. RESULTS: Umeclidinium/vilanterol treatment was dominant versus umeclidinium and salmeterol, providing an additional 0.090 LYs (95% range: 0.035, 0.158) and 0.055 QALYs (-0.059, 0.168) with total cost savings of £690 (£231, £1306) versus umeclidinium, and 0.174 LYs (0.076, 0.286) and 0.204 QALYs (0.079, 0.326) with savings of £1336 (£1006, £2032) versus salmeterol. In scenario and sensitivity analyses, umeclidinium/vilanterol was dominant versus umeclidinium except over a 5-year time horizon (more QALYs at higher total cost; ICER=£4/QALY gained) and at the lowest estimate of the St George's Respiratory Questionnaire treatment effect (fewer QALYs at lower total cost; ICER=£12,284/QALY gained); umeclidinium/vilanterol was consistently dominant versus salmeterol. At willingness-to-pay threshold of £20,000/QALY, probability that umeclidinium/vilanterol was cost-effective in this non-exacerbating subgroup was 95% versus umeclidinium and 100% versus salmeterol. CONCLUSION: Based on model predictions from a UK perspective, symptomatic patients with COPD and no exacerbations in the prior year receiving umeclidinium/vilanterol are expected to have better outcomes at lower costs versus umeclidinium and salmeterol.

Indoor air quality assessment in dwellings with different ventilation strategies in Nunavik and impacts on bacterial and fungal microbiota.

Indoor air quality is a major issue for public health, particularly in northern communities. In this extreme environment, adequate ventilation is crucial to provide a healthier indoor environment, especially in airtight dwellings. The main objective of the study is to assess the impact of ventilation systems and their optimization on microbial communities in bioaerosols and dust in 54 dwellings in Nunavik. Dwellings with three ventilation strategies (without mechanical ventilators, with heat recovery ventilators, and with energy recovery ventilators) were investigated before and after optimization of the ventilation systems. Indoor environmental conditions (temperature, relative humidity) and microbiological parameters (total bacteria, Aspergillus/Penicillium, endotoxin, and microbial biodiversity) were measured. Dust samples were collected in closed face cassettes with a polycarbonate filter using a micro-vacuum while a volume of 20 m3 of bioaerosols were collected on filters using a SASS3100 (airflow of 300 L/min). In bioaerosols, the median number of copies was 4.01 × 103 copies/m3 of air for total bacteria and 1.45 × 101 copies/m3 for Aspergillus/Penicillium. Median concentrations were 5.13 × 104 copies/mg of dust, 5.07 × 101 copies/mg, 9.98 EU/mg for total bacteria, Aspergillus/Penicillium and endotoxin concentrations, respectively. The main microorganisms were associated with human occupancy such as skin-related bacteria or yeasts, regardless of the type of ventilation.

Patient registries for home oxygen research and evaluation.

Randomized clinical trials are the preferred study design to address key research questions about the benefits or harms of interventions. However, randomized trials of oxygen therapy are difficult to conduct and have limitations. The purpose of this article is to offer our view on the potential use of patient registries in the field of home oxygen in COPD as an alternative to randomized trials by referring to the Swedish experience with a national registry for respiratory failure. Patient registries use observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure. As opposed to administrative databases, patient registries serve one or more predetermined scientific, clinical, or policy purposes. By systematically and prospectively compiling relevant data, patient registries may describe the natural history of a disease, determine effectiveness and cost-effectiveness, assess safety or harm, and measure quality of care. Registry-based randomized trials (ie, randomized trials within a clinical registry) combine the advantages of a prospective randomized trial with the strengths of a large-scale all-comers clinical registry. Challenges and issues in the design and implementation of patient registries include the representativeness of participants, data collection, quality assurance, ownership, and governance. Notwithstanding their limitations, patient registries represent valuable tools in the conduct of research in the area of home oxygen therapy.

Incorporating telemedicine into the integrated care of the COPD patient a summary of an interdisciplinary workshop held in Stresa, Italy, 7-8 September 2017.

This report is a summary of a workshop focusing on using telemedicine to facilitate the integrated care of chronic obstructive pulmonary disease (COPD). Twenty-five invited participants from 8 countries met for one and one-half days in Stresa, Italy on 7-8 September 2017, to discuss this topic. Participants included physiotherapists, nurses, a nurse practitioner, and physicians. While evidence-based data are always at the center of sound inference and recommendations, at this point in time the science behind telemedicine in COPD remains under-developed; therefore, this document reflects expert opinion and consensus. While telemedicine has great potential to expand and improve the care of our COPD patients, its application is still in its infancy. While studies have demonstrated its effectiveness in some patient-centered outcomes, the results are by no means consistently positive. Whereas this tool may potentially reduce health care costs by moving some medical interventions from centralized locations in to patient's home, its cost-effectiveness has had mixed results and telemonitoring has yet to prove its worth in the COPD population. These discordant results should not be unexpected in view of patient complexity and the heterogeneity of telemedicine. This is reflected in the very limited support offered by the National Health Services to a wider application of telemedicine in the integrated care of COPD patients. However, this situation should challenge us to develop the necessary science to clarify the role of telemedicine in the medical management of our patients, providing a better and definitive scientific basis to this approach.

Cost-effectiveness of FreeO2 in patients with chronic obstructive pulmonary disease hospitalised for acute exacerbations: analysis of a pilot study in Quebec.

OBJECTIVE: Conduct a cost-effectiveness analysis of FreeO2 technology versus manual oxygen-titration technology for patients with chronic obstructive pulmonary disease (COPD) hospitalised for acute exacerbations. SETTING: Tertiary acute care hospital in Quebec, Canada. PARTICIPANTS: 47 patients with COPD hospitalised for acute exacerbations. INTERVENTION: An automated oxygen-titration and oxygen-weaning technology. METHODS AND OUTCOMES: The costs for hospitalisation and follow-up for 180 days were calculated using a microcosting approach and included the cost of FreeO2 technology. Incremental cost-effectiveness ratios (ICERs) were calculated using bootstrap resampling with 5000 replications. The main effect variable was the percentage of time spent at the target oxygen saturation (SpO2). The other two effect variables were the time spent in hyperoxia (target SpO2+5%) and in severe hypoxaemia (SpO2 <85%). The resamplings were based on data from a randomised controlled trial with 47 patients with COPD hospitalised for acute exacerbations. RESULTS: FreeO2 generated savings of 20.7% of the per-patient costs at 180 days (ie, -$C2959.71). This decrease is nevertheless not significant at the 95% threshold (P=0.13), but the effect variables all improved (P<0.001). The improvement in the time spent at the target SpO2 was 56.3%. The ICERs indicate that FreeO2 technology is more cost-effective than manual oxygen titration with a savings of -$C96.91 per percentage point of time spent at the target SpO2 (95% CI -301.26 to 116.96). CONCLUSION: FreeO2 technology could significantly enhance the efficiency of the health system by reducing per-patient costs at 180 days. A study with a larger patient sample needs to be carried out to confirm these preliminary results. TRIAL REGISTRATION NUMBER: NCT01393015; Post-results.

Multi-center, randomized, placebo-controlled trial of nocturnal oxygen therapy in chronic obstructive pulmonary disease: a study protocol for the INOX trial.

BACKGROUND: Long-term oxygen therapy (LTOT) is the only component of the management of chronic obstructive pulmonary disease (COPD) that improves survival in patients with severe daytime hypoxemia. LTOT is usually provided by a stationary oxygen concentrator and is recommended to be used for at least 15-18 h a day. Several studies have demonstrated a deterioration in arterial blood gas pressures and oxygen saturation during sleep in patients with COPD, even in those not qualifying for LTOT. The suggestion has been made that the natural progression of COPD to its end stages of chronic pulmonary hypertension, severe hypoxemia, right heart failure, and death is dependent upon the severity of desaturation occurring during sleep. The primary objective of the International Nocturnal Oxygen (INOX) trial is to determine, in patients with COPD not qualifying for LTOT but who present significant nocturnal arterial oxygen desaturation, whether nocturnal oxygen provided for a period of 3 years decreases mortality or delay the prescription of LTOT. METHODS: The INOX trial is a 3-year, multi-center, placebo-controlled, randomized trial of nocturnal oxygen therapy added to usual care. Eligible patients are those with a diagnosis of COPD supported by a history of past smoking and obstructive disease who fulfill our definition of significant nocturnal oxygen desaturation (i.e., ≥ 30% of the recording time with transcutaneous arterial oxygen saturation < 90% on either of two consecutive recordings). Patients allocated in the control group receive room air delivered by a concentrator modified to deliver 21% oxygen. The comparison is double blind. The primary outcome is a composite of mortality from all cause or requirement for LTOT. Secondary outcomes include quality of life and utility measures, costs from a societal perspective and compliance with oxygen therapy. The follow-up period is intended to last at least 3 years. DISCUSSION: The benefits of LTOT have been demonstrated whereas those of nocturnal oxygen therapy alone have not. The INOX trial will likely determine whether supplemental oxygen during sleep is effective in reducing mortality, delaying the need for LTOT and improving health-related quality of life in patients with COPD who desaturate overnight. TRIAL REGISTRATION: Current Controlled Trials ISRCTN50085100 ; ClinicalTrials.gov NCT01044628 (date of registration: January 6, 2010).

The COPD Assessment Test: Can It Discriminate Across COPD Subpopulations?

BACKGROUND: The COPD Assessment Test (CAT) is a valid disease-specific questionnaire measuring health status. However, knowledge concerning its use regarding patient and disease characteristics remains limited. Our main objective was to assess the degree to which the CAT score varies and can discriminate between specific patient population groups. METHODS: The Canadian Cohort Obstructive Lung Disease (CanCOLD) is a random-sampled, population-based, multicenter, prospective cohort that includes subjects with COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] classifications 1 to 3). The CAT questionnaire was administered at three visits (baseline, 1.5 years, and 3 years). The CAT total score was determined for sex, age groups, smoking status, GOLD classification, exacerbations, and comorbidities. RESULTS: A total of 716 subjects with COPD were included in the analysis. The majority of subjects (72.5%) were not previously diagnosed with COPD. The mean FEV1/FVC ratio was 61.1 ± 8.1%, with a mean FEV1 % predicted of 82.3 ± 19.3%. The mean CAT scores were 5.8 ± 5.0, 9.6 ± 6.7, and 16.1 ± 10.0 for GOLD 1, 2, and 3+ classifications, respectively. Higher CAT scores were observed in women, current smokers, ever-smokers, and subjects with a previous diagnosis of COPD. The CAT was also able to distinguish between subjects who experience exacerbations vs those who had no exacerbation. CONCLUSIONS: These results suggest that the CAT, originally designed for use in clinically symptomatic patients with COPD, can also be used in individuals with mild airflow obstruction and newly diagnosed COPD. In addition, the CAT was able to discriminate between sexes and subjects who experience frequent and infrequent exacerbations. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00920348; Study ID No.: IRO-93326.

Undiagnosed Chronic Obstructive Pulmonary Disease Contributes to the Burden of Health Care Use. Data from the CanCOLD Study.

RATIONALE: Chronic obstructive pulmonary disease (COPD) remains undiagnosed in many individuals with persistent airflow limitation. These individuals may be susceptible to exacerbation-like respiratory events that consume health care resources. OBJECTIVES: To compare exacerbation-like respiratory events, event prevalence, and differences in the odds of using medication and/or health services between subjects with diagnosed and undiagnosed COPD. METHODS: Subjects sampled from the general population participating in the CanCOLD (Canadian Cohort Obstructive Lung Disease) study, with at least 12 months of exacerbation-event follow-up who were classified as having physician-diagnosed or undiagnosed COPD were assessed. Exacerbation-like respiratory events were captured using a questionnaire administered every 3 months. MEASUREMENTS AND MAIN RESULTS: A total of 355 subjects were undiagnosed and 150 were diagnosed with COPD. Undiagnosed subjects were less symptomatic and functionally impaired, had been prescribed fewer respiratory medications, and had better health status. The incidence of reported exacerbation-like events was higher in diagnosed subjects and increased in both groups with the severity of airflow obstruction. Although subjects with diagnosed COPD were more often prescribed medication for exacerbation events, health service use for exacerbation events was similar in both groups. CONCLUSIONS: Most subjects with COPD in Canada remain undiagnosed. These subjects are less symptomatic and impaired, which may partly explain lack of diagnosis. Although patients with undiagnosed COPD experience fewer exacerbations than those with diagnosed COPD, they use a similar amount of health services for exacerbation events; thus, the overall health system burden of exacerbations in those with undiagnosed COPD is considerable.

Eligibility for home oxygen programs and funding across Canada.

BACKGROUND: In Canada, although medical insurance is generally universal, significant differences exist in the provision of home oxygen therapy across the country. OBJECTIVE: To systematically compare the terms of reference for home oxygen across Canada, with a focus on the clinical inclusion criteria to the programs. METHODS: The authors searched the terms of reference of the 10 Canadian provinces and three territories, focusing on general eligibility criteria for home oxygen (including blood gas criteria, and eligibility criteria for ambulatory and nocturnal oxygen), and compared the eligibility criteria to the widely accepted criteria of the Nocturnal Oxygen Therapy Trial (NOTT) trial, the clinical recommendations of the Canadian Thoracic Society and the results of Cochrane reviews. RESULTS: The terms of reference for nine provinces were retrieved. All jurisdictions have similar criteria for long-term oxygen therapy, with slight differences in the thresholds of prescription and the clinical criteria defining 'pulmonary hypertension' or 'cor pulmonale'. The use of oxyhemoglobin saturation as a criterion for funding is inconsistent. All nine provinces fund nocturnal oxygen, all with different clinical criteria. Funding for portable oxygen widely varies across provinces, whether the ambulatory equipment is offered to patients on long-term oxygen therapy or to those who have isolated exercise-induced desaturation. The terms of reimbursement are very heterogeneous. CONCLUSIONS: Heterogeneity exists in the criteria for eligibility to home oxygen programs and funding across Canada. Terms of prescription and reimbursement of oxygen are not necessarily supported by available evidence from the current literature in several Canadian jurisdictions.

Utility Scores In Patients With Oxygen-Dependent COPD: A Case-Control Study.

BACKGROUND: Utility measures that summarize the health-related quality of life of an individual using a single number usually between 0 (death) and 1 (full health) are useful to quantify the benefits of health care interventions in terms of quality-adjusted life years (QALYs) and to help prioritizing limited health resources from cost-effectiveness analyses among patients with different health conditions. OBJECTIVE: To determine utility scores in patients with oxygen-dependent chronic obstructive pulmonary disease (COPD). METHODS: Patients with oxygen-dependent COPD (the cases) were matched, on a 1:2 basis, to COPD controls according to gender, age (± 5 years) and FEV1 (±5% predicted). Utility scores were obtained from the SF-6D, a measure derived from the SF-36. RESULTS: From a cohort of 102 patients with oxygen-dependent COPD, 68 (42 men; mean age: 71 years; mean FEV1: 35% predicted) were successfully matched with 136 controls. We found clinically and statistically significant differences in mean utility scores between cases (0.588 ± 0.071) and controls (0.627 ± 0.085; p = 0.001). The same differences were observed in men and women. CONCLUSION: Oxygen-dependence adds to the burden of disease in terms of quality of life. These utility scores may be useful in cost-utility analyses involving patients with oxygen-dependent COPD.

Assessment of daily life physical activities in pulmonary arterial hypertension.

BACKGROUND: In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient's daily life physical activities (DL(PA)). Whether DL(PA) are decreased in PAH and whether the 6MWT is representative of patient's DL(PA) remain unknown. METHODS: 15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities >3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DL(PA). RESULTS: The mean number of daily steps and the mean daily energy expenditure and duration of physical activities >3 METs were all reduced in PAH patients compared to their controls (all p<0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r = 0.76, p<0.01 and r = 0.85, p<0.01), respectively. CONCLUSION: DL(PA) are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DL(PA) in PAH.

Comparative assessment of the quadriceps and the diaphragm in patients with COPD.

Chronic obstructive pulmonary disease (COPD) and other chronic diseases such as heart failure are accompanied by skeletal muscle alterations that further enhance morbidity and mortality in affected individuals. Several studies have highlighted important structural and biochemical modifications in limb and respiratory muscles in COPD. Reviewing the similarities and differences between the two most studied muscles in COPD, the quadriceps and the diaphragm, may be helpful in providing important clues about the mechanisms underlying muscle changes associated with this disease. Although oxidative stress is present in both muscles, other muscle alterations are clearly distinct between the quadriceps and the diaphragm. For example, the oxidative metabolism varies in opposite directions, the diaphragm exhibiting increased resistance to fatigue while the quadriceps in COPD is characterized by premature fatigability. Differences in muscle phenotypic expression between the diaphragm and the quadriceps indicate that, in addition to systemic factors, the local microenvironment must participate in the reorganization seen in these two skeletal muscles in COPD.

Assessment of muscle fatigue during exercise in chronic obstructive pulmonary disease.

Contractile fatigue is associated with exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Contractile fatigue may be assessed by quantifying the decline in strength after a fatiguing protocol but this may pose practical problems. The purpose of this study was to investigate the relationship between the decline in quadriceps strength, quadriceps electrical activity, perception of leg fatigue, and arterial lactate level in patients with COPD during constant work-rate cycling exercise. The decline in quadriceps strength was significantly associated with the decrease in electromyographic median frequency (r = 0.606), leg fatigue perception (r = 0.453), and arterial lactate level (r = 0.384). Using the receiver-operating-characteristic curve, it was found that a 4% decline in electromyographic median frequency had a 94% sensitivity and a 75% specificity to predict contractile fatigue. We conclude that contractile fatigue commonly occurs during cycling exercise in COPD. The electromyographic median frequency appears to be a valuable indirect marker to predict contractile leg fatigue.

The Canadian Optimal Therapy of COPD Trial: design, organization and patient recruitment.

BACKGROUND: There are no published studies that have assessed whether adding long-acting beta 2-agonist bronchodilators and/or inhaled steroids to chronic therapy with tiotropium would provide additional clinical benefit to patients with moderate to severe chronic obstructive pulmonary disease (COPD). METHODS: The Canadian Optimal Therapy of COPD Trial is a randomized, prospective, double-blind, placebo-controlled, multicentre trial funded by the Canadian Institutes of Health Research that has been designed to determine which combination of inhaled medications will most effectively prevent exacerbations and optimize disease-specific quality of life in patients with COPD. The trial is the first to evolve from the Canadian Thoracic Society Clinical Trials Group. The study will randomize 432 patients with moderate to severe COPD to one of three parallel treatment arms for 52 weeks: tiotropium and fluticasone/salmeterol; tiotropium and salmeterol; or tiotropium and placebo inhaler. The participants will be allowed to use salbutamol as required throughout the trial period. OUTCOMES: The primary outcome measure is the proportion of patients in the three treatment groups who experienced a respiratory exacerbation within 52 weeks of randomization. Other outcomes that will be assessed over the 52-week trial period will include: changes in disease-specific quality of life and changes in dyspnea, health care use and changes in lung function. A pharmacoeconomic analysis will also be performed to evaluate the cost of these therapies. RESULTS: The study commenced recruitment in October 2003. It is currently operating at 22 centres across Canada and has randomized 137 patients during the first four months of recruitment. Recruitment is scheduled to continue until April 2005 or until 432 patients have been randomized. CONCLUSION: The present randomized, placebo-controlled trial offers a unique opportunity to answer the question, what is the best combination of inhaled medications to use for COPD patients? It is hoped that optimal use of inhaled medications will improve patient health and quality of life, reduce patient respiratory exacerbations, and ultimately, reduce health care resource use.

French-Canadian version of the Chronic Respiratory and St George's Respiratory questionnaires: an assessment of their psychometric properties in patients with chronic obstructive pulmonary disease.

BACKGROUND: French versions of the Chronic Respiratory Questionnaire (CRQ) and the St George's Respiratory Questionnaire (SGRQ) have largely been used in Canada, although the process by which they were translated remains unknown and the psychometric properties of these translated versions have not been assessed in a properly designed study. OBJECTIVE: To translate and evaluate the psychometric properties of the French-Canadian versions of the CRQ and the SGRQ. METHODS: The questionnaires were translated according to standardized guidelines for cross-cultural adaptation. Measurements were made at baseline and again after two weeks in 27 chronic obstructive pulmonary disease (COPD) patients known to have stable disease. Measurements were also taken pre- and post-treatment in patients with acute exacerbation of COPD (33 patients) or in pulmonary rehabilitation (32 patients). RESULTS: The CRQ showed high test-retest reliability (the majority above 0.70), although it was slightly lower for the dyspnea dimension (0.58 to 0.65). The SGRQ also showed high test-retest reliability (above 0.80), although it was lower for the symptoms dimension (0.54 to 0.58). The internal consistency reliability coefficients ranged from 0.73 to 0.90 for the CRQ and above 0.80 for the SGRQ, except for the symptoms dimension. The Pearson's correlation coefficients were low (less than 0.30) between most of the translated questionnaire dimension scores and forced expiratory volume in 1 s, 6 min walking test and dyspnea measures. The correlation was generally high (greater than 0.50) between the two questionnaires and the 36-item short form health survey, and for those domains that measured the same construct. The changes in the total and subscale scores of the CRQ and the SGRQ (except for the symptoms domain) were all largely above the variability of the score in the stable disease group. CONCLUSION: The present study confirms that the French-Canadian translated versions of the CRQ and the SGRQ perform well with respect to their psychometric properties. They are both suitable for their intended purpose, ie, to detect change in health status in patients with COPD when assessing if a treatment is beneficial. However, the symptoms domain of the SGRQ cannot be used to assess acute change with respect to a given therapy.