French-Canadian Version of the Chronic Respiratory and of the 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

Fatigability of Lower Limb Muscles during Walking in Chronic Obstructive Pulmonary Disease

Background: Patients with chronic obstructive pulmonary disease (COPD) perceive much less quadriceps fatigue during walking compare to cycling. Whether other lower limb muscles could develop fatigue during walking is unknown. The purpose of this study was to assess the electrical activity of five lower limb muscles during a 6-minute walking test in 11 healthy subjects and in 10 patients with COPD matched for age and activity level. Methods: Surface electromyographic (EMG) data were recorded in five muscle groups (soleus, gastrocnemius (GM), tibialis anterior, vastus lateralis and rectus femoris) of the right leg during the walking test. The EMG median frequency of all contractions at minute 2 and 6 were averaged for each muscle group. Ventilation, oxygen consumption and CO2 production were also continuously measured throughout the test. Results: Although the walking distance (494 &#177; 116 vs. 625 &#177; 50 m; P < 0.01) and the walking speed (1.7 &#177; 0.4 vs. 2.1 &#177; 1.2 m&#183;s-1; P < 0.01) were reduced in COPD compared with controls, patients worked at a higher percentage of their estimated maximum voluntary ventilation during the test (118 &#177; 32 % vs. 51 &#177; 14 %; P < 0.01). The time course of the EMG median frequency from minute 2 to 6 differed between patients with COPD and healthy controls for the soleus, GM and tibialis anterior suggesting the occurrence of a muscle fatiguing profile in COPD. Conclusions: Evidences of a fatiguing profile was found in three lower limb muscle groups during walking in COPD despite a slower walking speed compared to healthy controls

Predicting the rate of oxygen consumption during the 3-minute constant-rate stair stepping and shuttle tests in people with chronic obstructive pulmonary disease

Background: The 3-minute constant-rate stair stepping (3-min CRSST) and constant-speed shuttle tests (3-min CSST) were developed to assess breathlessness in response to a standardized exercise stimulus. Estimating the rate of oxygen consumption (V'O2) during these tests would assist clinicians to relate the stepping/shuttle speeds that elicit breathlessness to daily physical activities with a similar metabolic demand. This study: (I) developed equations to estimate the V'O2 of these tests in people with chronic obstructive pulmonary disease (COPD); and (II) compared the newly developed and American College of Sports Medicine (ACSM) metabolic equations for estimating the V'O2 of these tests. Methods: This study was a retrospective analysis of people with COPD who completed a 3-min CRSST (n=98) or 3-min CSST (n=69). Multivariate linear regression estimated predictors (alpha <0.05) of V'O2 to construct COPD-specific metabolic equations. The mean squared error (MSE) of the COPD-specific and ACSM equations was calculated and compared. Bland-Altman analyses evaluated level of agreement between measured and predicted V'O2 using each equation; limits of agreement (LoA) and patterns of bias were compared. Results: Stepping rate/shuttle speed and body mass were identified as significant predictors of V'O2. The MSE of the COPD-specific equations was 0.05 L.min?1 for both tests. Mean difference between measured and predicted V'O2 was 0.00 L.min?1 (95% LoA ?0.46, 0.46) and 0.00 L.min?1 (95% LoA ?0.44, 0.44) for the 3-min CRSST and 3-min CSST, respectively. For the ACSM metabolic equations, the MSE was 0.10 L.min?1 and 0.18 L.min?1 for the 3-min CRSST and 3-min CSST, respectively. The ACSM metabolic equations underestimated V'O2 of the 3-min CRSST by ?0.18 L.min?1 (95% LoA ?0.68, 0.32), and overestimated V'O2 of the 3-min CSST by 0.35 L.min?1 (95% LoA ?0.14, 0.84). Conclusions: This study presents metabolic equations to predict V'O2 of the 3-min CRSST and 3-min CSST for people with COPD that are more accurate than the ACSM metabolic equations

Behavioural interventions targeting physical activity improve psychocognitive outcomes in COPD

This study explored the impact of a self-management behaviour modification (SMBM) programme with/without bronchodilators and with/without exercise training (ExT) to improve daily physical activity on psychological and cognitive outcomes in COPD patients as a secondary analysis of the PHYSACTO trial. A 12-week, four-group, randomised, partially double-blind, placebo-controlled, parallel-group trial of SMBM in addition to tiotropium 5 µg, tiotropium/olodaterol 5/5 µg, tiotropium/olodaterol 5/5 µg plus ExT, or placebo was conducted in 304 patients. Outcomes included anxiety (Hospital Anxiety and Depression Scale (HADS)-A), depression (HADS-D and Patient-Health Questionnaire (PHQ)-9) and cognitive function (Montreal Cognitive Assessment (MoCA)). All outcomes showed statistically and clinically significant improvements after 12 weeks independent of treatment group. However, greater improvements in HADS-A and MoCA were seen in patients who exhibited greater increases in physical activity and exercise capacity, respectively, whereas greater improvements in HADS-D and PHQ-9 were seen in patients who exhibited increases in either physical activity or exercise capacity. The results indicate that SMBM with/without bronchodilators or ExT was associated with improved psychological and cognitive functioning. Anxiety reduced with increased physical activity, cognitive function improved with increased exercise capacity, and depression reduced with increases in either physical activity or exercise capacity. Interventions that increase daily physical activity or exercise capacity may improve psychological and cognitive outcomes in COPD.status: publishe

Intraindividual variability in serum alpha-1 antitrypsin levels

Background: Measuring alpha-1 antitrypsin (AAT) serum levels is often the first step when investigating for alpha-1 antitrypsin deficiency (AATD). The purpose of this study was to determine the test-retest reproducibility of AAT serum levels and to determine if between-measurements variability was associated with acute phase markers of inflammation. Methods: We retrospectively analyzed a sample of 255 patients from a community respirology practice with chronic obstructive pulmonary disease (COPD) in whom AAT serum levels were measured twice, on separate visits. White blood cell count and fibrinogen were also measured at the time of the second blood sampling as markers of acute phase inflammation. Intraclass correlation coefficient (ICC), Pearson correlation coefficient, and Bland-Altman analysis were used to document test-retest reproducibility. Regression analyses were used to identify potential correlates of test-retest AAT level differences. Results: Although the 2 AAT serum levels were significantly correlated, the between-measurement agreement was weak (ICC of 0.38 [95% confidence interval (CI), 0.27 to 0.48]; Pearson correlation coefficient of 0.34 [95% CI, 0.23 to 0.44]) and Bland-Altman analysis revealed wide 95% limits of agreement. Considering that an AAT serum level below 1.13g/L should trigger further investigations to confirm the AAT status, discrepancies between the test-retest AAT levels resulted in reconsidering requirement for further investigation in 22% of patients. A significant correlation between the fibrinogen value and the second AAT level was found (r=0.21, p=0.004 [n=173]). Conclusions: Serum AAT levels showed weak intra-individual reproducibility which could lead to AATD status misclassification and potentially a missed diagnosis of AATD.</p

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.Peer Reviewe